by Frank Justice

At present these instructions are written around the sliding canopy only since that is what I built. You can still use some of the sections if you have the tip-up.

Brake Hoses and Tubing
  1. The single brake system for the RV-6 is shown on drawing #40 and the RV-6A and dual brake systems are shown in drawing #49. There is also some information in the construction manual. Install the fluid reservoir and the lines and elbows on the cylinders. The elbows need to be screwed in fairly tight right up to where they should be pointed; if you have to back them out a little bit they may leak so be careful. Use gasket sealing compound on the elbows. In order to get the brass inserts to go all the way inside the plastic tubing you may need to put the outer ferrule on the tube, start the insert in the tube, heat the end in near boiling water, and then force the insert in by pushing the tube end against a wall. If on the other hand the insert is too loose and won't stay in place, put a little sealing compound on it first to hold it. The reservoir needs to be installed above the upper firewall stiffener just high enough that you can screw in the nylon Tee fitting to it after the reservoir is mounted; keep in mind you will need to be able to see the fluid level at the top.
  2. Install the elbows in the firewall (RV-6) or straight fittings in the angle on the firewall (RV-6A) and connect the hoses from the master cylinders to them. For the RV-6A install the elbows along along the sides of the fuselage and connect aluminum tubing from these back to the fittings on the firewall angle. The elbows should be placed far enough forward of the F-602 bulkheads so they do not interfere with the later placement of the F-696 tank attach angles (drawing #46). There is room between the wing and the fuselage to later route the brake line from this elbow along the fuselage to the gear leg. The elbow is not placed right next to the gear leg because there is a gap between the fuselage skin and the heavy gusset in this area and tightening the elbow in place deflects the skin.

Tank Vent Tubes
Install the tank vent tubing inside the fuselage as shown in drawing 49. Make a hole about 3/8" diameter in the fuselage side skin for the tube to go out to the tank. The hole location is not critical as there is plenty of room between the outside of the skin and the inside wall of the tank to make bends in the tubing. There should be about one foot of tubing outside the hole. If you do not have the bottom skin on at this time just leave a little extra length at the forward end of the tube so it can be fitted later.

Empenage Fairings
  1. The empenage is faired in with a molded fiberglass top piece F-649B and aluminum strips F-649A on the sides under the horizontal stabilizer. These are shown in drawing #46. The fiberglass fairing normally needs considerable rework; most builders find that it will not go far enough back to properly fit around the leading edges of the horizontal stabilizers because it hits the vertical stabilizer. If it is cut out around the vertical stabilizer enough to allow the leading edges to lay properly on the horizontal stabilizer, it may not overlap the F-610 bulkhead where attaching screws must go. It is actually fairly easy to cut off a section that is incorrect and remake it to the proper shape.
  2. Trim the fairing as necessary to make it sit in the desired location. If your fairing is as described above you can trim some at the front of the vertical stabilizer (but not so much that it moves so far back there is not enough fairing left to attach to the F-610 bulkhead), then cut off the part of the sides that do not conform to the horizontal stabilizer leading edges. You then only have to rebuild those two small areas as described below.
  3. Hold the fairing in place and drill #40 the holes for attachment of it to the stabilizers, making sure they all go through rib flanges and miss other ribs and rivets, where you can attach nutplates later. Also drill one hole on each side at the front just above the cut-out area such that it will go through the flange of the bulkhead and not just the topskin.
  4. On the inside of the fairing grind off all high spots, and if you had to cut through any flanges that go right against a skin bevel them back about one inch on the inside.
  5. Coat the area on the skins where the fairing will touch them with fiberglass mold-releasing compound to keep new resin from sticking to them. A film of old-fashioned carnuba auto wax will also work; put it on and allow it to dry. Auto polish will not work well, and do not use a wax with silicone in it as it will keep paint from sticking later. Some types of packaging tape also work well; test it first, and lay it on without any creases.
  6. Working with polyester resin and cloth is quite easy if you do it right. Get a bunch of cheap acid brushes (stiff, ragged bristles, metal tube handle); these are used to mix the resin, to apply it, and also to move the fiberglass cloth around. Nothing else, not even your fingers, will have to touch the stuff. Things to remember: the strength is in the fiberglass, not the resin; use only enough resin to wet the cloth at each stage; make sure the cloth is thoroughly wet (no white spots remain) and that there are no gaps between cloth layers (also visible as lighter-colored areas); the wet cloth will stick to and be pulled out of shape by anything you touch it with except the wet brush; wet fiberglass cloth can be easily made to conform to any shape imaginable, although you may have to experiment some with the best angle to cut out you piece with respect to the direction of the weave of the cloth. One other trick when working with larger pieces is cloth (you may not need it here) is to brush on some resin, let it start setting up, then stick the cloth to it; it will stay in place and you can work it with your fingers. Also, remember to thoroughly clean any surface that may have the wax or mold release compound on it before trying to apply another layer of resin.
  7. Cut out a few pieces of medium weight fiberglass cloth of the right shape to make new areas and also overlap the existing fairing by about one inch. Mix a small batch (about two teaspoons) of polyester resin (auto body or boat repair types are fine). You will have about five minutes from the time you mix a batch until it starts getting stiff. Brush it on the inside of the fairing. Lay a piece of cloth on the fairing and wet the rest of the cloth; lay another piece of cloth on the first. Put the fairing in place and cleco it down. Use the brush to work the cloth into the right shape and to get it completely wetted. Lay another piece of cloth on top and wet it. After this hardens you can do more layers until you get the new area formed. Then grind off the outside in the area around the joint just deep enough that you can do one layer of fiberglass there. Be sure to pull out the clecos before the resin gets too hard (about 1 hour).
  8. To finish the fairing, trim it all around until it extends only about three-quarters of an inch past the future screw holes. Then lay a layer of fiberglass and resin on the inside on all the surfaces that lay against the empenage skins and cleco the fairing down. Use the brush to smooth and fill all the edges. When the resin sets up, smooth out the new areas and round all the edges. The final thickness of the flanges where the screws go must be at least 1/8" to provide enough material to countersink for the screw heads.
  9. While you are waiting for resin to set up you can make the F-694A gap covers (bottom fairings) as shown in drawing #46.. An easy way to get them the right shape is the carpet-layer's trick; measure the distance down from the lowest point on the horizontal stabilizer to where the bottom edge of the fairing will be (about the same level as the bottom of the main longeron), tape the fairing material on the fuselage with the bottom edge parallel to the main longeronand the forward edge butted against the top skin rather than overlapping it, mark a point on the fairing the same distance up from the bottom and the same location as what you measured previously, measure from the bottom of the horizontal stabilizer down to this mark, then make a series of marks this same distance down from the horizontal stabilizer. Cut along these points and it should fit almost exactly along the stabilizer and will not need trimming on the bottom edge. Mark good locations for mounting holes down on the side skin where you can see them with the fairing in place. Tape the fairing in place and drill it #40 to the main longeron. Remove it, drill out the holes to #30, and dimple them.
  10. Remove the stabilizers. Mount nutplates on the stabilizers and the fuselage at F-610. Drill out the holes in the fairing and countersink them. Drill out the holes for the bottom fairing in the main longeron. The drawings show to tap these holes for 6-32 screws, and countersink them. This is not easy because the tap has a tendency to bind up and break in thick aluminum. Since you can install this fairing now and never have to take it off again, it is easier to just use locking nuts on the fairing attach screws. If you do tap the holes, do not tap them completely; stop at a point where when you put the screw in it is a little hard to turn. Use cutting oil or kerosene for a lubricant and work the tap in and out as you go to reduce friction. Install the bottom fairings.
  11. You can now permanently install the stabilizers, the top fairing, the rudder, and elevators, or you can set them aside for later if you expect to have to move the project to finish it.

Sliding Canopy Windscreen Supports Installation
  1. Thi section describes mounting the Wd-641 windscreen frame and its forward support on the cockpit deck as shown in drawings SC-1 and SC-2. First drill the holes in the Wd-641 bottom plates such that the bolts will go through the canopy decks just inside of the main longeron. Then drill the holes in the canopy decks through them. Rivet the four C-668 spacers (found in bag #908) in place to the main longerons with a single AN426AD3 rivet each, then drill them for the bolts. Do not make the shims for the forward bolt holes yet. Mount the Wd-641 using non-locking nuts (1/4-28 or 1/4" FINE or 1/4" UNF thread) but do not tighten the nuts on the bolts completely.
  2. The standard windscreen frame support bar Wd-643 is made out of a steel alloy that can cause errors in compass readings if the compass is mounted on or next to it. For this reason Van's makes a non-magnetic stainless steel support bar as an option at a small extra cost with trade-in of the standard bar. You will not need this if you are planning a panel-mounted compass located in the middle of the pilot's half of the instrument panel; a compass is best not located in the center of the panel anyway because that will put it too close to electronics which are likely to cause indication errors.
  3. Cleco the forward structure and forward topskin in place. Figure out where the Wd-643 windscreen frame support bar will go. Use drawing SC-1 which shows the plate on the bar extending aft of the F-6109 plate on the center rib; this will probably give you the best results in terms of the lower end of the tube part of Wd-643 laying flat on the topskin. Exact placement of the Wd-643 is not critical; it just must not touch the F-6105 bulkhead flange. Decide where the rear end of the slot must be for the Wd-643. From the underside drill a hole #30 right next to the left side of the center rib in the general area of the slot; use this hole for reference to make the rest of the slot. To make the shortest possible slot, plan on holding the bar vertical, putting the plate through the slot, and then tilting the bar back and down into place. Trim the bar and plate as required to allow it to sit right on the skin without distorting it. Cut the excess off the top end of the bar so it will fit in the channel in the Wd-641. Verify that the Wd-641 is vertical (actually, perpendicular to the main longerons). Drill the bolt hole just over 1/4" for attaching the Wd-643 to the Wd-641windscreen support. With the support bar in place put a bolt in the hole. Verify again that the Wd-641 is vertical, then drill one of the two holes #12 for the bolts that will attach the Wd-643 plate to the F-6109 plate and F-6108 center rib.
  4. Find the thinnest piece of aluminum strip you have that is no more than about 1 1/2" wide and is as long as the distance between the firewall and the plate on the Wd-643. This is to be made into a template for cutting the piece of angle that will go between the firewall and the Wd-643 plate as shown in drawing SC-2. Slide this strip between the end of the F-6105 half and the center rib, then trim its ends to be just like the angle must be; make sure you have oriented it to take into account the one mounting hole you have already drilled. Mark on the F-6105 bulkhead where it must be cut out to allow the angle to pass through. Remove the strip and use it to make the support angle. Cut out the F-6105 for the angle to pass through. The side of the angle that sticks out is toward the bottom (one view on SC-2 shows it on top which is incorrect). You do not need to cut out the flange part of the F-6105 if you don't want to. Put everything back in place and drill the support angle to the Wd-643 and the center rib and F-6109 plate in two places. Drill #30 the support angle to the firewall stiffener.
  5. Remove the topskin and drill more holes as needed to secure the F-6109 plate to the center rib; avoid areas where they would hit the support angle or the Wd-643 plate.

Finishing Rear Top Skin and Canopy Decks for Sliding Canopy
  1. Place the steel canopy frame on the fuselage with the front end almost touching the Wd-641 windscreen support. Place the C-677 channel pieces on the canopy deck located as shown in drawing SC-1; the rear edge of the channel should be about even with the point of the "V" made by the canopy frame rear hold-down pin and the plate it is attached to. Mark the position of the forward end of the C-677 channels on the canopy decks.
  2. Attach the rear top skin F-6112 (labelled incorrectly as F-674 in earlier drawings) with a few clecos and mark a line on the inside of it that follows the curve of the rear edge of the canopy frame. Set the canopy frame and windscreen support aside. Remove and trim the canopy deck ends.
  3. Remove the rear top skin. Make a new line on it about two and one-half inches to the rear of the one drawn along the canopy frame except right at the ends. See drawing SC-1 which shows the edge of the skin as trimmed with the funny little curve near the main longerons. The skin should overhang the F-606 bulkhead along the top of the fuselage by about one and one-half inches. Trim the the skin along the new line. Save the piece that you cut out as a template to give to fellow builders.
  4. Replace the rear top skin on the fuselage and drill the F-6111 stiffener channels to it. You will have to move the stiffeners around to find the exact place where the web part matches the curve of the skin, then bend the flanges in or out as required to make them lay against the skin so they do not alter the natural curve of it. Otherwise, you will have a tough time making the canopy rear skirt close on the skin right. Dimple and rivet the stiffeners to the skin.
  5. Rivet the rear top skin to the fuselage.
  6. Rivet together the forward structure (it may be easier to do this on the bench instead of on the fuselage) including the three ribs, the F-6105 bulkhead halves, and F-6109. Rivet the forward structure to the fuselage and firewall. Rivet the canopy decks to the fuselage and the forward structure.
  7. Put the Wd-641 windscreen support in place. Make the wedge-shaped shims that go under the Wd-641 at the front bolts, making sure that they are of the proper thickness that the Wd-641 is perpendicular to the canopy decks. Put the bolts in to hold down the Wd-641 still using non-locking nuts.

Canopy Frame Mounting
  1. Assemble the canopy frame forward end rollers to the Wd-644 brackets. The roller parts are found in bag #908; see drawing SC-1. The smaller brass spacer may have to be forcibly pressed into the larger one in a vise; the ends line up on one end. The screw is a washer-head type, and the locknut is a thin type. Tighten the nut firmly; if the roller does not rotate freely, shave a little off the flat side so the screw head will squeeze only on the brass spacers and not on the roller. Tape the roller assemblies to the canopy frame for now; do not drill them.
  2. Cut the piece of canopy track extrusion material C-657 in half and lay the pieces on the canopy decks. Mark and cut the tracks to the same length as the canopy deck pieces. Set the canopy frame in place with the tracks on the rollers; clamp the tracks in place such that the canopy frame stays centered on the fuselage and the rollers stay centered in the tracks as you move the canopy backward and forward. Drill 11/64" the canopy tracks to the canopy decks (for #8 screws). Secure the tracks to the decks with a couple of screws and non-locking nuts.
  3. Look carefully at Detail B of SC-1and you will see a flap of the rear topskin that is bent down starting at the forward edge of the F-606 bulkhead. This flap is two inches wide and centered on the fuselage (the gap where the flanges of the two bulkhead halves meet). Slice the skin and bend it down as shown.
  4. The rear canopy track is made by drilling and riveting the C-662 strip and C-663 bar together. First place the bar on the topskin as shown in SC-1 detail B. Modify the straight part if necessary to make it lay flat against the skin. Bend the strip to match the bar curvature. In the center of the bent-down part of the strip at its forward end drill a hole for attaching the C-664 1/4" threaded rod. Drill and rivet the strip to the bar as shown. Note that the bottom side of the bar is countersunk as well as the top side of the strip. Put the rivets in from the top side.
  5. Drill the C-661 plastic block to the canopy frame 3/16". Note that this block must pivot to some extent as the rear of the canopy moves from an open to a closed postion; locate the holes carefully. Put in a bolt to hold the block in place.
  6. Mark lines on the topskin sideways out from all the rivets that are along the fuselage centerline.
  7. Put the canopy frame in place with the rollers in the tracks. Slide the rear track into the rear block on the frame and tape it to the fuselage positioned so that as the canopy frame moves rearward it stays centered on the fuselage. Mark the position on the track where the rear edge of the block sits when the canopy frame is slid back to where the rollers come to the ends of the canopy tracks. Cut off the rear track just aft of this point. Drill the track to the fuselage 5/32" (for #6 screws) using the previously-made rivet locator marks to avoid them. Countersink these holes. Attach the track with the proper hardware; it will not have to be removed later.
  8. Slide the canopy frame back and forth to make sure nothing binds up at the rear.
  9. Drill a hole through the F-606 bulkhead for attaching the rear end of the C-664 1/4" threaded rod; the hole does not have to line up precisely with the hole in the track. Put the C-664 rod in place but do not tighten the nuts. The three AD316-4 nuts called out here may not be in your kit; you can either call Van's to get them or find ordinary zinc-plated steel 1/4-28 nuts (may be labelled as 1/4 FINE or 1/4 UNF) where a large selection of hardware is sold.
  10. Place the C-677 channels (in bag #908) at the rear ends of the canopy tracks and drill them 3/16" or #12 to the canopy decks as shown in drawing SC-2 detail A. Make sure you avoid existing rivets and the flange of the bulkhead. Attach them securely with the washer-head screws using non-locking nuts.
  11. Put the plastic blocks C-665 (in bag #908) in place in the channels and drill the attachment holes 3/16" or #12. Make sure these holes are out of the way of the opening you will be making for the canopy frame pin (see drawing SC-1).
  12. Drilling the holes in the blocks for the canopy frame lockdown pins properly requires a little thinking. When the canopy is completely closed the outer edge of the frame should be 1/16" inboard of the outside of the side skin; this allows for the thickness of the canopy side skins which will be put on later. The canopy frame is actually slightly wider than this at the rear, so it must be pulled in by the pins engaging the blocks as the canopy closes. It is also helpful in sealing the canopy edges if the canopy is also pulled downward slightly as it closes. The holes in the block are drilled at an odd angle; this angle is determined not by the amount of pulling but by the angle of the locking pin on the canopy frame. The angle of the locking pin with respect to the frame is designed to provide the proper pulling action. In order for the pulling actions to occur properly, the entrance of the holes on the rear edges of the blocks must be located such that they correspond with the desired position of the locking pin body when the canopy is completely closed.
  13. Punch a hole in a piece of duct tape the same size as the canopy frame locking pin. Slide the canopy frame all the way forward. Hold the rear corner of the canopy frame slightly down and inward as described above and attach the tape over the rear of the C-677 channel with the locking pin in the hole in the tape. Slide the canopy out of the way and ecure the blocks to the channels with screws (no nuts required). Mark the entrance hole using the hole in the tape as a guide.
  14. Drill the C-665 blocks starting with a #30 and then enlarge the hole with a drill that is just a little larger than the locking pin. The angle of the hole in the block is not critical but should match the angle of the locking pin. Slide the canopy frame forward and file the rear edge of the block as necessary to accomodate the plate that holds the locking pin and also the downward movement of the pin as it is pulled by the block.

Canopy Latch
  1. Place the big brass bushing C-667 (in bag #908) on the shaft of the Wd-642 latch handle as shown in drawing SC-1 section A-A'. It may be necessary to file out the inside of the bushing slightly. Attach the C-654 latch as shown. It may be necessary to file the latch to allow it to fit completely over the bushing. Drill holes for the spring and attach it.
  2. Slide the canopy latch assembly into the tube in the canopy frame. Trim off the latch mounting tube on the inside of the canopy frame just enough to allow the latch arm to swing into the the proper position on the latch pin on the windscreen support frame.
  3. Put the canopy latch mechanism in place up as far as it will go. Set the upper latch handle on the tube sticking out of the top of the canopy, leaving just enough space for the C-671 plastic ring to fit between the handle and the top of the canopy frame tube (this is the rain seal). With the latch in the closed position turn the handle so it is pointing rearward and drill the latch tube through the hole in the handle. Remove the latch, drill out the latch tube big enough to accomodate a #8 screw, and tap the handle for a #8 screw (you will probably have to drill the handle to about #24 for this). Countersink the hole in the handle. Do not install the handle at this time.
  4. Leave the latch closed for fitting the canopy.

Fitting the Canopy and Windscreen to the Frame and Fuselage
  1. The following instructions are for more recent canopies sold by Van's; earlier canopies may require slightly different techniques in the early stages of trimming.
  2. Put a piece of duct tape over the top of the latch tube that sticks out of the canopy frame to keep it from scratching the canopy. Put masking tape over the surfaces of the canopy frame and the windshield frame everywhere the canopy will touch them; do not push the tape down hard; lay it on lightly.

Initial Canopy Placement and Drilling to Windscreen Frame
  1. Trim off all parts of the canopy related to its support during the molding process; that is, everything that you know will not be there in the end. Use the abrasive cutoff wheels supplied in the kit (bag 908) for this. The best tool to drive the cutoff wheel is a drill that will run about 800 to 1200 RPM and is variable speed. A die grinder doesn't have enough power. Push down with moderate pressure and move the tool fast enough that you only cut about one-third of the way through in each pass. If you lay a strip of masking tape with its edge along the cut line for the final trim you will be able to make a straighter cut. Always move in the direction that the cutting wheel pulls you; if you are cutting the other way when the wheel cuts all the way through it will be pulled down into the slot and this may cause trouble. Be especially careful in making the last pass in areas where the cut line is curved; the wheel will bind up and try to jump out of the groove.
  2. The canopy needs to be located at the right fore-aft position so that it touches the canopy frame (Wd-640) and windscreen frame (Wd-641) at all points except possibly at some points along the front bow of the canopy frame. (The front bow of the canopy frame and the windscreen frame may not have quite the same curve so you fit to the windscreen frame and later put shims in as required between the canopy and the canopy frame front bow.) As the canopy comes from the factory it sits much too high off the frame to be able to determine the right fore-aft position. The canopy latch rod will at some point in the process get in the way by holding the canopy off the frame, but by the time you have reached that point you should be able to determine the correct canopy position so the hole for the latch tube can be drilled in the canopy. To accomplish proper fitting you must trim the canopy a little at a time, mostly at the front, slowly bringing the canopy down and always rechecking the fore-aft position. Move it forward and backward until the curve of the top of the canopy seems to match that of the top fore-aft bar in the canopy frame. When the canopy is close enough to the frame that you can tell it is correctly positioned, cut off the rear of the canopy about 1" aft of the canopy frame rear bow. When the canopy gets so low it hits the top of the latch tube, carefully center it by seeing how the front of it sits on the forward top skin and how the rear sits on the canopy frame rear bow, then drill the hole for the latch tube to go through the canopy. Before trimming further you must pull in the sides of the canopy so they touch the canopy frame side bars. This is necessary to make the front fit correctly (as you pull in the sides the front changes shape). You will have to trim off the sides of the canopy about even with the center of the canopy frame side bars in order to put clamps on. Keep trimming the front until the canopy sits on the windscreen frame and the canopy frame top fore-aft bar, and does not quite touch the forward top skin.
  3. Push the canopy down on the windscreen frame and canopy frame; as you do you will see the masking tape turn darker right where the canopy touches it. This marks the line you want to drill on, as it will be centered on the tubes. If there is any point where this mark is not made on the windscreen bow because the canopy frame front bow sits higher than the windscreen frame, file down one or both ends of the canopy frame front bow where the roller brackets go so it will sit lower. Tape the canopy in place at the front and drill it #40 to the windscreen frame, starting at the top and working down on both sides.

Final Front Roller Adjustment and Drilling to Canopy Frame Front
  1. Try pushing up on the canopy frame from inside; if it will go up some before it contacts the canopy at the top, hold the roller bracket down while pushing up on the frame and fill the resulting gap between the bracket and tube end by wrapping a turn of wire of the proper gauge around the roller bracket tube.
  2. Drill #40 the canopy to the canopy frame front bow. Be careful to center these holes on the tube and to make them perpendicular to the canopy surface where you don't have a mark on the masking tape to go by.
  3. Make shims about 1/2" square with #30 holes in the center as required to fill any gap between the canopy and the canopy frame. Label the shims to correspond to their proper locations. A quick way to do this is to make a bunch of small strips of thin aluminum and record how many srips are required at each location to fill the gap. Then make all the real shims later using the number of strips as a measurement guide. I thought about trying to modify the shape of the canopy frame front bar so it would more closely match that of the windscreen frame but did not try it. Another builder told me he tried but found the bar was too hard to bend.

Drilling to Canopy Frame Top Bar
Refer to drawing SC-1 section C-C' for the attachment of the canopy to the top of the canopy frame. Mark a line down the center of the C-653 and C-678 aluminum strips. Make some marks on the canopy so you can place the C-653 strip exactly centered on the canopy frame fore-aft tube. Drill #40 through the C-653 strip, the canopy, and the canopy frame tube. Remove the C-653 strip and use it as a guide to drill the C-678 strip. Cleco the top strip and the canopy to the canopy frame; set the inside strip aside for now.

Cutting the Canopy Away from the Windscreen
Make this cut approximately halfway between the windscreen support bow and the canopy front bow tube. You can remove some of the clecoes holding the canopy to the windscreen frame for this operation. When you make the cut, do not cut all the way through at the bottom and right at the top until you have cut through everywhere else; this will hold the two sides together so they won't bind up on the cutting wheel. Replace the clecoes in the windscreen frame.

Making Side Skirts
  1. Clamp the rear of the canopy to the rear bow of the canopy frame Starting at the top and working down, making sure the canopy makes good contact with the tube along its length. Make sure you have good marks in the masking tape for the center of the canopy frame side tubes, then trim off the sides of the canopy even with the tops of the canopy frame side bars. Make a mark along the center of the dark mark in the masking tape.
  2. Using a straightedge make marks on the forward top skin and the aft top skin that correspond to the center of the canopy frame side tubes and to the top of the canopy deck. Also verify that the side tube does not bow up or down; if it does, note by how much at the center. Lay a strip of masking tape on the canopy extending up from the bottom edge by about 1". On this strip make a series of marks exactly one inch above the center of the canopy frame tube. Cut off the joggled part of the inside side skirt C-659 at and beyond where it would hit the upright bows of the canopy frame. Also cut off just enough of the main part of the skirt aft of the rear bow to clear the aft top skin. File off any welding bead along the side of the canopy frame that would keep the skirt from laying flat on it. Put it in place as shown in SC-1 (Canopy Rivet Detail) and SC-2 detail A. Using the marks on the top skins mark the centerline of the rivet holes for attaching the skirt to the canopy frame side tube. Verify the location of this centerline using the marks on the masking tape. This line must bend if the tube was bowed up or down. Mark the location of the rivet holes. Remove the skirt and drill #40 the rivet holes. These holes must be centered on the tubes precisely or the canopy skirt will lean in or out and not line up with the fuselage side skin; if you do have a problem with this you can "move" the holes a little as you drill them out to final size later.
  3. Lay the drilled side skirt on top of the C-660 outside side skirt with one edge of the C-660 even with the edge of the C-659 nearest the joggle. Drill #40 the C-660 through the C-659. Also drill #41 the line of holes for the rivets that hold the inner and outer skirts together at the bottom; the rearmost hole of this line should be at least two inches forward of the end of the side tube. Cut off the rear end of the outside skirt so it will not overlap the aft top skin.
  4. Put just the C-659 inside side skirt in place with the mark on the side tube visible through the holes in the skirt. Carefully drill the side skirt to the tube, making sure the drill does not wander and take the side skirt with it. Remove the skirt, cleco the outer skirt to it just at the center, and cleco this assembly to the side tube just at the center. Working from the center outward, cleco the assembly to the tube and redrill through the holes so the clecoes will go in easily (This is necessary because you drilled the outside skirt with it flat but the relationship of the holes between skirts shifts as you bent them to fit the canopy frame tubes.) This should result in a nice even curve of the skirt.
  5. Drill #40 the side skirts to the canopy. With clecos in these holes the side skirts will probably swing out at the bottom and not align with the fuselage sides anymore. This is because the canopy side is not exactly vertical where the skirts attach. This will be fixed later. Put in place the thick plastic strip that the canopy attachment screws go into. This is labelled C-652 in earlier drawings and manuals but is later kits use C-624 for this. Drill this through the holes in the skirts and canopy.
  6. Mark a line on the outside skirt so you can trim it even with the top of the canopy deck and just forward of the aft top skin. You can also trim the skirt so that it overlaps the side skin a little in order to give a better seal; not that in order for the canopy to slide open you cannot have this overlap in the forward few inches of the skirt. Remove the skirts and trim. Put them back on.

Fitting the Canopy Rear Skirt
  1. Remove the clamps holding the rear of the canopy to the canopy frame. The clecos in the side skirts must hold the canopy in place against the frame rear bow or very nearly so. If not, you must use heavy tape secured to the frame, not the fuselage, to achieve this.
  2. Make a 4" long straightedge out of scrap. Hold this with the forward end even with the center of the canopy frame rear bow and the rear end straight behind against the aft top skin. If at any point the straightedge ENDS cannot touch the canopy and the skin at the same time, fix it so they will. This may require trimming more off the rear edge of the canopy or adjusting the position of the nuts holding the end of the rear track to the fuselage.
  3. Cut out the C-666 rear skirt halves using the pattern already marked on the aluminum sheet. Deburr the edges.
  4. Apply masking tape to the canopy at the rear, starting just forward of the center of the canopy frame bow center and extending forward from there by about three inches. Make a series of marks on this tape at 1/2" forward of the center of the tube center and 2" forward of the tube center.
  5. Raise the rear of the canopy frame at the rear by about 1/8" by loosening the rear holddown block bolts and sliding shims under the blocks. This will allow you to get a tighter final fit of the rear skirt to the aft topskin when the canopy is closed.
  6. Lay a rear skirt piece on the canopy and fuselage. Bend it to make it fit without requiring significant force to hold it down. This cannot be done by brute force. The bending must be along a diagonal rather than straight across the skirt, that is, bend and twist at the same time so that the skirt will lay down on both the canopy and the skin as it curves down and forward. Bend just a little at a time so as not to develop waves in the skirt. Neither the front nor the rear edge of the skirt will line up properly with the canopy frame or the aft skin; just make sure the skin front edge does not completely uncover any of the marks that are 1/2" forward of the canopy frame tube. The skirt will probably overlap both the fuselage centerline at the top and the side skirt at the bottom in the best-fitting position. Start at the top; when the first third is properly curved tape it to the aft skin at the top and pull down and forward on the bottom edge to see how the rest will fit; pull down to make it conform to the canopy and pull forward to make it conform to the aft skin. Recheck the position and shift it if necessary. Then remove, bend some more, and repeat.
  7. When the skirt is bent enough that it will stay in place when taped down, mark a cut line on it that is 1/2" forward of the canopy frame tube using the marks you have on the masking tape for reference. Also mark the fuselage centerline at the top and an area to notch out to clear the canopy rear track. Remove the skirt and trim it. Replace it and tape it down securely. Using the marks on the tape for reference drill #40 the skirt to the canopy and canopy frame starting at the top. Use 2" spacing; earlier drawings show 3" on one view. Drill the rear skirt to the side skirts by continuing the lower line of holes in the side skirts rearward, making sure none of the holes will hidden behind the canopy frame rear pin support plates where you won't be able to buck rivets later.
  8. Mark a line on the bottom edge even with the bottom edge of the side skirt. Make a mark on the side skirt at the forward edge of the rear skirt. Note whether there is a slight bulge in the skirts where the side tube and the rear bow of the canopy frame join; if so this will be fixed later. Remove the skirt and trim the bottom edge.
  9. Make the skirt for the other side in the same way, except after you drill it cleco the first skirt on top of it and mark the top end of the first skirt onto the second. Remove the rear skirts. Trim the second skirt along the line.
  10. Reattach the rear skirts at least at the top. Make a cover for the area at the top where you notched out the skirts to clear the rear canopy track. It should be about three inches wide and should extend rearward of the rear of the skirts enough to insure that rain will not come in. Joggle it in such a way that it is flat at the front but a channel develops going rearward that is just high and wide enough at the back to clear the track. It will be very difficult to make the required bends in aircraft aluminum alloy unless you have a press brake, so get some soft aluminum about 0.016 thick (flashing material or the stuff they make the walls out of for outdoor aluminum room enclosures). Cut out a rectangle 3 1/2" wide and about 1" longer than the width of the rear skirt at the top. Mark two parallel lines 1" apart down the middle (long way). Make another line outside of each, meeting the other line at one end and 5/16" away at the other. Bend more than 90 degrees along the inner lines to make a channel, then bend out along the other lines so you wind up with a hat section at one end an a flat surface at the other. Trim to suit your eye. Drill it #41 to the skirt halves in the area between the plexiglass and the rear topskin. Remove this item and the rear skirt halves. If the track cover also covered up holes for attaching the rear skirt and canopy to the canopy frame, back drill the cover through the side skirts.

Completing the Canopy Assembly
  1. Enlarge to #30 and countersink the holes in the side skirt that are for attaching them to the canopy frame tubes.
  2. Enlarge the holes in the rear skirts to #30 except the ones that are for joining them only to the side skirts and to the rear track cover plate. If the rear track cover plate covered up one of the holes for attaching the rear skirt to the canopy frame, cleco the cover to the skirt and drill it through the skirt. Enlarge the holes in the canopy frame.
  3. Remove the side skirts and the top strip. If you had a bulge in the side and rear skirts due to the canopy frame rear bow, mark on the canopy where it hits the rear bow, remove the canopy, and grind out a depression about 1 1/2" long and about as deep as the bulge was so the canopy material won't push the skirts out. Round the edges of the skirts and top strip where they lay against the plexiglass. Bevel the underside of the rear of the rear skirts and so they won't dig into the paint on the aft topskin.
  4. Dimple the lower and upper row of holes in the side skirts, all of the holes in the rear skirts and the rear canopy track cover, and the holes in the top strip. Countersink all of the holes in the canopy.
  5. It is easier to paint the canopy skirts and top strips on their inside surfaces with the finish color now before you attach them to the plexiglass. The canopy frame, canopy latch mechanism, windscreen frame, and windscreen support bar should also be painted now. In fact, this is really the best time to paint the whole inside. Then you won't have trouble getting paint into corners and you won't have to mask anything. For best results remove the canopy tracks and rear brackets for painting.
  6. Make sure the canopy frame roller brackets are oriented in the frame so the rollers will roll straight. Clamp the tube tightly so it squeezes on the roller braket. Drill #12 the canopy frame to the roller bracket. Attach the roller brackets to the frame with the proper hardware.
  7. Install the canopy tracks and the windscreen frame with the correct hardware. Set the canopy frame in the tracks and put in the bolt to hold the rear slider block (no nut needed now). Install the rear blocks at the end of the tracks. Leave the frame back a few inches rather than in the closed position. Set the canopy in position on the frame.
  8. Rivet the rear skirt halves together with the rear track cover; this should be at least partially done with a couple of clecoes holding each rear skin to the canopy and frame so that the rear skirt assembly will fit later. Remove the rear skirt assembly.
  9. Cleco the outer side skirts to the canopy just well enough that you can lay a strip of masking tape on the canopy even with the top of the skirt. Cleco on the rear skirts and do the same. Remove the skirts. Lay a fairly thick bead of clear RTV or regular aircraft windshield sealant on the inside of a side skirt right at the top (don't go below the line of holes). Cleco the skirt to the canopy only, using a cleco in every hole. Do the other skirt. Lay a bead of sealer along the leading edge of the rear skirt assembly and put it in place with a cleco in every hole including the ones that attach it to the side skirts.
  10. After the sealer has set up, remove the clecoes holding the side skirts and carefully put the inside part of the side skirts in place. Put clecos in the holes through the canopy first to avoid loosening the canopy to skirt seal. Rivet the bottom row of holes that hold the inner skirt to the outer one and also to the rear skirt. You can loosen clecoes that hold the canopy to the frame if necesssary to reach all of these rivets.
  11. Cleco the side skirts to the canopy frame and close the canopy. If the bottom of the skirt lines up with the fuselage side skin you can rivet it to the canopy frame now. If not, you will have to force the canopy into the right alignment with some kind of hardening filler such as Bondo between the skirt and the canopy frame so that when the filler hardens the skirt will keep its position.
  12. Put the top strips in place and rivet the canopy top to the canopy frame. Rivet the rear skirt and canopy to the canopy frame. Rivet the front of the canopy to the canopy frame with the shims. The rivets supplied with the kit for this may be either too long or too short. In some cases the remainder of the mandrel may protrude out from the head of the rivet and it must be cut off with a cutoff wheel. In the area where you had to use shims at the front bow of the canopy frame, make sure the rivet grips properly; it won't if the shim had to be more than about 3/32" thick. You must obtain longer grip length rivets for these locations.
  13. Seal around the hole in the canopy with RTV and assemble the latch mechanism to the frame. You may want to use a rubber O-ring rather than the plastic washer supplied in order to get a better seal between the handle and the tube.
  14. Verify that the canopy will open freely; the shop heads of some of the rivets you just put in may hit the rear topskin. Trim and/or bend the topskin as required.

Completing the Forward Topskin
  1. Notch the forward top skin approximately as shown in drawing SC-2 and put the windscreen in the slot. Mark the skin for trimming aft of the slot so it will overlap the canopy by about 3/4".
  2. Drill the skin #30 to the fuselage in any areas where you did not go previously, such as in the area aft of the notch.
  3. Remove the skin and trim. Also round off the sharp corner forward of the notch to a radius of about 1"and bevel the outside edge of the section of skin where it will lay against the outside of the windscreen. Dimple the skin as required. Countersink any remaining holes in the fuselage. Replace the skin.
  4. If you plan to install a lighted compass on the stainless steel windscreen support bar, drill a hole in the skin for a pair of wires to go up through the bar and put a grommet in it. You will also need to drill a hole in the bar for the wires to exit. Note that the windscreen bow is an aircraft alloy steel and can cause errors if the compass is too close to the top of the support bar. While the compass can be compensated for this to some extent you might end up wanting to move it down on the bar a little; keep this in mind when drilling the hole for the wires. About 6" down the bar is a good location.
  5. Install the windscreen support bar with the proper hardware (put the compass light wires in it first, making sure the wires are tightly twisted together for the upper eight inches so they will not create a magnetic field that interferes with compass operation).
  6. You can rivet the topskin to the fuselage except along the firewall flanges now but it is not essential for finishing the windscreen. If you have already riveted on the forward bottom skin you should seriously consider not riveting on the topskin at this time because there is still a lot to be done under it.

Finishing the Windscreen
  1. The procedure for finishing the windscreen in the construction manual is straightforward and calls for attaching it permanently with made-in-place fiberglass-epoxy trim. I decided to see if I could make the windscreen more removable so that the fiberglass work would not have to be redone if the windscreen ever had to be replaced. I was also worried about rain getting in where the canopy meets the windscreen. The following procedure is the result. For those who hate fiberglass work it is a little easier.
  2. If necessary trim the lower edge of the windscreen so it does not quite touch the forward topskin. There should not be any large gaps however as that make finishing harder. Finish the rear edge so it is straight and does not have cutmarks in it. It should be a smooth edge or rain leaks will occur. The gap between the windscreen and canopy edges should be consistent. You can gauge the straightness better by filing it while it is still attached to the windscreen bow.
  3. If you want to make the windscreen removable make a hold-down bracket for the front of the windscreen. This is not shown in the plans because in normal construction the windscreen is simply bonded to the fuselage with adhesive. It is a strip of 0.032" aluminum about 1 1/4" wide and 6" long, bent up about 30 degrees along a line 1/2" from one side. This is slipped under the windscreen at center with the smaller side against the topskin and the larger side against the back side of the windscreen. Drill it to the topskin, drill the winscreen to it in two places near the ends, mount platenuts on it at the two windscreen holes, and rivet it to the topskin. Put temporary screws in to hold the windscreen in place at this bracket. Additional shorter brackets can be placed at various points along the topskin but these are not necessary if you use a strong sealing compound when you mount the windscreen.
  4. Van's manual calls for making a molded-in-place fiberglass strip to overhang the windscreen at the rear by 1/4 to 1/2". This covers up the gap to provide smooth airflow and hold down the canopy front but by itself will not seal out rain. It also presents the risk of serious finger shortening if you aren't careful closing the canopy. The latch seems to do a good job of holding the canopy down. You will need to have a thin strip of rubber in the gap between the windscreen and canopy anyway, so you could just make the strip overhang by just enough to cover this. Do not try to get by without this strip; if you install flush-head screws directly into plexiglass it will soon crack at the holes from the lateral stress caused by tightening the screws.
  5. Instead of making the gap cover strip out of fiberglass, you can easily make it out of aluminum instead. Remove the clecoes on one side of the windscreen, including the one in the center. Drill #30 through two or three of the holes for screws that will hold the windscreen to the bow on that side. Countersink the windscreen at the enlarged holes and put in #6 flathead screws. If you use throwaway screws (you can force them in but it tears up the threads) you won't have to tap the holes.
  6. Make a heavy paper pattern first. Cut a strip about 6" wide and long enough to reach from below the forward topskin lower edge to past the center of the windscreen at the top. Tape it at the lower end and then force it down on the windscreen at the trailing edge. Mark it along the underside at the edge of the windscreen. Remove the pattern and trim it so it is a curved strip about 2" wide. Mark this onto a piece of 0.032 aluminum and cut out the strip. Smooth the edges of the strip and and lay some tape on the windscreen to avoid scratches. Verify that the strip fits like you want.
  7. Since it would be difficult to find and reuse the holes already drilled in the windscreen, we will mark their positions on the trailing edge of the windscreen and drill new ones that avoid the old ones. You also need to record how far back from the windscreen edge each hole is.
  8. Starting at the lower end force the strip onto the windscreen so that it lays flat and overhangs the edge of the windscreen by the amount you want plus about 1/2" extra. Drill new holes #40 starting just above the forward topskin edge and continuing around to near the center. Also drill a hole that will hold the top edge of the forward topskin and the windscreen to the bow. Be very careful to drill these holes perpendicular to the strip surface. Mark the windscreen center on that end of the strip, the top edge of the forward topskin on the other end, and the edge of the windscreen on the underside of the strip. Remove the strip and trim the ends. Trim the long edge leaving an overhang of 1/8 to 1/4" or whatever your choice is based on the previous discussion of this.
  9. Drill out the holes in the strips and the one in the top of the forward topskin to #30, dimple them, then drill them out more if necessary to allow a #6 screw to go through.
  10. Make the strip for the other side in the same manner.
  11. Remove the windscreen. Drill the new holes in the windscreen to allow a #6 screw to go through. Countersink these holes.
  12. Drill the holes in the windscreen support bow to #36 and tap these holes 6-32. Be very careful here; the tap will tend to bind up in this hard steel and break unless you hold it aligned exactly with the hole. You should also work the tap in and out, advancing in very small steps.
  13. Bevel the front edge of the strips and round the rear edge. Set the strips aside for now.
  14. The fairing around the front of the windscreen can be made partly or completely out of aluminum. The part that starts at the rear edge and goes about 12" forward does not need to have a compound curve so it can easily be made of aluminum. The area covered here is fairly large and in fiberglass represents a lot of labor. The rest of the fairing around the front of the windscreen would normally have a considerable compound curve to it so would be harder to make out of aluminum without a metal shrinker. It can be done without this if you are patient and use pure soft aluminum such as roof flashing material rather than an aircraft alloy. If you can make the strip narrow and thin enough you will be able to force it to conform the the windscreen curve without buckling due to the windscreen-to-topskin bend. One builder says he even left the strip flat and it still looked good. On the other hand, this area is fairly easy to do in fiberglass. If you plan to make the windscreen removable and want to do part or all of the fairing in fiberglass, apply masking tape to the windscreen and wax it where the resin will touch it. If you do this you can use polyester resin instead of epoxy since the resin will not touch the plexiglass. You can finish installing the windscreen now, but if you plan to put in defrost ducts or make some kind of dashboard cover you should leave the windscreen out until that is done.

Windscreen Defrost Suggestion
  1. No provision is made in the kit for windscreen defrost. You should consider making this based on your own experiences and flying plans. Here is one way to do it if you have the sliding canopy. There is very limited space behind the instrument panel for defrost ductwork; it is so tight that for some instruments you may have to punch a clearance hole in the bulkhead behind the panel.
  2. Cut 2" diameter holes in the F-6105 bulkhead (the one behind the instrument panel) about 1" below the topskin and 1" to the outside of each F-6107 rib. Buy two of the 2" duct flanges from Vans (part number VENT DL-03) or make your own and drill them to the forward side of the F-6105 bulkhead at the holes.
  3. Make a wedge-shaped plenum to go aft of the bulkhead to direct the air from the hole in the bulkhead to a hole in the topskin (not made yet). This plenum should be about 5 1/2" wide, 5 1/2" from front to back, and about 2 1/2" high at the forward edge. Make a template out of stiff cardboard first, then when you transfer it to aluminum add tabs all the way around. Bend this up and drill it to the topskin, the rib, and the bulkhead.
  4. Use the holes you drilled in the topskin as a guide to make an air opening in it. This hole should be about 4" long and about 1" wide. Make a screen for the hole to keep things from falling in an rivet it in place. Rivet in the wedge and the tube flange.
  5. The rest of this is left to the builder to connect. You can now install the windscreen if you desire.

Cowling Mounting Hinges
  1. Measure the thickness of your cowling to determine how thick the spacers under the hinge sections should be. The drawing calls out 0.032 material for the spacers but a thicker one is likely to be needed, especially across the top, so that you don't have to shave down the cowling to get a smooth skin line. See drawing #31.
  2. Drill the 17" long heavy hinges to the firewall sides including the spacer material as shown in sections D-D' and E-E'. Use the piece of hinge material that is just over 34" long for these. Verify that the side skins completely covers the spacer and the firewall side pieces; if not, trim them carefully making sure you do not cut into the side skins (the straight edge of the side skins makes it easier to trim the cowling to fit). Rivet these on and the remainder of the side skin to the firewall, but leave out about two at the bottom so you will be able to get the forward bottom skin on later.
  3. After riveting, check the lay of the skin line in this area to make sure it is satisfactory to you; the angle of the flanges on the firewall sides is normally not quite right but it tends to improve after riveting. If you want to make it straighter make a heavy wooden block to fit inside the flange, notched to clear the hinge eyes, and beat on the skin side (protected with a smaller block).
  4. Make the hinges and shims that will support the cowling top as shown in drawing #31. Make sure the gap at the top is on the right side of the aircraft (or on the side where the oil dipstick access door will be for the engine you plan to use). Rivet on the hinges and spacers to the topskin and firewall. Hold the mating hinge sections up to these; note that because of the bow in the hinge you will have to file the hinge eyes to make the hinge sections fit together easily. You will also have to flute the cowling hinge to make it not stick up the wrong way.
  5. Make the short hinge sections that go on the bottom of the firewall. Note that the bottom skin is thicker than the side and top skins so the shim required under the hinge may not need to be as thick as the others. Do not rivet these on.

Mounting the Engine Mount
  1. Sometimes the engine mount you get will not line up exacly with the holes in the firewall. Most of the time the error is not great enough to cause any trouble. There is a fair amount of flex possible in the upper two mounting points but not in the bottom. For this reason the process of enlarging the bolt holes starts at the bottom.
  2. Have an assistant hold the engine mount up to the firewall and see if the two bottom holes can be lined up almost exactly with the holes in the firewall. If so, drill out one of the holes to 3/8", put a bolt in to hold that point, and drill the other hole through the engine mount to get perfect alignment. If there is considerable misalignment you will first have to file one or both of the holes in the direction that will produce better alignment so that the drilling operation will not tear up the engine mount. Put a bolt in the new hole.
  3. Drill the other two bottom holes through the engine mount by first drilling a smaller pilot hole. You will find a piece of 3/8" outside diameter tubing in the kit that you can insert in the engine mount hole to use as a guide for a smaller drill bit. The drill out the holes to 3/8".
  4. Verify that the upper engine mount holes line up with the holes in the firewall. If they don't, file them out so they line up better. Drill the upper two holes to 3/8".
  5. Install the six bolts and tighten them. Do not put in the cotter keys. Normally the bolts would be put in from the cockpit side so you can tighten the nuts more easily; if you expect to remove the engine mount later and are by yourself it will be easier to get the mount on installing the bolts from the engine mount side.

Sequence of Engine Mounting/Cowling Fitting/ Bottom Skin Riveting
You will need to mount the engine in order to make the cowling and to do everything else in the engine compartment and firewall. You will probably want to leave the forward bottom skin off for a while to do the instruments and engine hookups but you need the skin mounted at least temporarily to fit the bottom cowling. You can't drive some of the bottom skin to cowling hinge rivets with the engine mount in place unless you use pop rivets in a few places (depending on how skinny your squeezer or bucking bar is). The engine is hard to get mounted on a Dynafocal motor mount but it is easy to get the motor mount lined up with the firewall. The following is a brief description of the order in which these instructions go. You should consider changing the order if it does not fit your long-range plans or if you don't mind using pop rivets. If you already have the bottom skin riveted on but not the top skin, this is not a concern because the motor mount does not interfere with riveting the top skin. The considerations might include how you plan to transport the finished fuselage to the airport. When you have reached this point nothing is made extremely difficult or impossible by having the forward bottom skin riveted on.
  1. Mount the engine more or less permanently to the motor mount.
  2. Cleco on the forward bottom skin.
  3. Trim the top and bottom cowling to fit.
  4. Cleco the cowling bottom-attach hinge halves to the firewall.
  5. Finish the cowling and leave it off.
  6. Remove the bottom skin.
  7. Finish the engine hookup and instruments.
  8. Remove the engine by removing the motor mount to firewall bolts.
  9. Rivet on the forward bottom skin and hinge.
  10. Remount the engine/motor mount assembly permanently.

Mounting the Engine
  1. Engine mounting is adequately described in the construction manual. Use the right hardware so that the holes in the bolts line up with the slots in the nuts. The exact number and type of big washers to use is determined partly by the motor mount design, so look in the construction manual for this rather than in the sheet that comes with the rubber shock vibration absorbers. As of this date there is a washer between the engine and the rubber mount on the bottom bolts but not on the top. You can put in the cotter keys now but you might as well wait just in case you need to readjust the hardware. If so, put tape at the bolts so you won't forget before you fly. Some builders have reported that after the engine was run for a little while (a few minutes to a couple of hours) the rubber mounts would compress and allow the engine front to sag by about 1/8"and not line up with the cowling any more. Not all builders have seen this. Either you find some way to run the engine for a while before fitting the cowling or you plan to fix it by either adding another washer later on the bottom (the bolt is long enough) or you leave off the extra large washer on the bottom mount while fitting the cowling then add it back in later.
  2. If you are building a -6A you will need to provide some means to prevent the fuselage from falling on its nose when you mount the engine. You will also need to have the nose gear leg in place to finish the cowling on the -6A. To solve both problems, put the nose gear leg in place in the motor mount but twist it upside down (the bottom end pointing up), with some blocks of wood under the end. On the -6 you may need to add some weight or a tiedown to the tail; any brace you put under the engine would be in the way of cowl fitting.

Carburetor Air Box (first steps)
  1. The carburetor airbox needs to be made and mounted to the engine before the cowling air scoop can be fabricated and attached. Van's sells kits for airboxes for different engines (the O-360 is larger).
  2. The air box and the air scoop on the cowling must be aligned and built together. For now, attach the VA-131-C mount plate to the carburetor and cut out an opening to clear the carburetor drain structure if necessary with your carburetor. You may also find it necessary to make a gasket to go between the carburetor and the mount plate so the plate will sit flat and not hit some built-up areas on the carburetor. Do not bother to cut the nose off the airbox at this time as the directions say. Remove the mount plate. Tape the mount plate to the VA-131-B top plate with the 5 degree angle as described (this is because the carburetor on the O-360 is located about 1" to the left of the engine centerline).
  3. If you are building an RV-6A, attach the mount plate/top plate assembly to the carburetor. Make a cutout in the rear of the air box so that the box will not come closer than about 1/2" to the nose gear leg when fitted onto the top plate. The rest of the air box is finished later.

Mounting the Cowling
  1. The instructions for making the cowling in the construction manual section 12 are fairly complete but not in the right order (things you need at the beginning are found at the end). Read that whole section before starting. There is a separate article from the RVator (Cowling Installation: Making that Other Material Work") which describes how to use heat to get the distortion out of the front of the cowling sections. Do this first. It is not necessary that you get it perfect at first; you will go back and tweak it later. To quickly understand the nature of the distortion, tape the top and bottom halves of the cowling together and set this assembly nose-up on the floor. Place the spinner rear bulkhead on top and note that it doesn't lay flat. You must reach inside and squeeze the ends of the air inlet ducts together to force the front surfaces into alignment while applying heat. You will find it useful to place a 1500 watt room heater on the floor inside this assembly to help provide heat since hair dryers do not work very well on the white outer surface. While you have the top and bottom sections taped together and the spinner bulkhead laying on them note about how much you will be able to trim the cowling edges where the top and bottom meet so that you will have a perfect circle at the front.
  2. If you have the right cowling for the propeller and extension you plan to use, you will only have to trim an inch more or less at the rear of the cowling. The rear spinner bulkhead is used as the reference for the location of the front of the cowling. For a fixed-pitch prop mount your prop extension on the starter gear ring and mount the spinner bulkhead on the extension. If you are going to mount a compact-hub constant-speed propeller (like Van's sells) the rear spinner bulkhead mounts on the propeller rather than behind it. Since it is easier to work on the cowling without the prop in place, make a spacer block out of wood that is 2" thick. This comes from how far forward of the starter ring gear front surface that the FRONT surface of the rear spinner bulkhead sits on the compact-hub constant-speed prop (2 1/4") and the thickness of the spinner bulkhead. Here you mount the rear spinner bulkhead REAR surface on this block to help you fit the cowl.
  3. Carefully mark a trim reference line 1 1/2" back from the front edge of the side and top skins.
  4. During the trimming process it is very important to have the cowling fixed firmly in the proper position and you must be able to take it off and get it back on in exactly the same position. To get the top cowling aligned properly for trimming first make horizontal marks 2" long on the side skins 17 3/4" up from the bottom of the firewall as mentioned in the manual. Tape the spinner bulkhead to the starter or engine block so it cannot rotate. Stick some foam rubber or wadded-up newspaper on top of the engine to hold the cowling front about the right level until you can clamp it to the bulkhead.
  5. Put the top cowling in place and clamp it directly to the spinner bulkhead (the bulkhead is already about 1/8-inch rearward of its normal position if mounted on the propeller). Make sure the front of the cowling is level by measuring up from the floor to points on both sides; if you try to do this just by looking at the front you may be fooled because the engine doesn't look the same on both sides. Make marks on the spinner bulkhead and the cowling so you can later get the cowling back on in the exact same position. Make sure the cowling bottom edges overlap the marks you made on the sides an equal amount on both sides. Mark the rear trim line on the cowling using the reference marks on the side and top skins as a starting point. Remove the cowling and and cut along your line, preferably using the cutting disk supplied with the kit for cutting the canopy. Put the cowling back in place and clamp it to the spinner bulkhead. Make a reference mark at the center of the rear of the cowling onto the top skin so you can easily get it back in the right position. You can now trim the rear edge of the cowling for a perfect fit. The side of the cutting disk works well for this but don't push too hard and break the disk. It helps to tape one side to secure it while you trim on the other side. As you trim the high spots you can add spacers between the spinner bulkhead and the cowling. You should wind up with about 1/8" spacing between the cowling and the spinner bulkhead; with the propeller installed the gap will be somewhere between 3/16 and 1/4".
  6. Grind off the inside of the rear of the cowling to make the thickness the same in the area where the hinges will attach. Attach the cowling half hinges to the firewall half hinges with a piece of .095" hinge pin (smaller than the pin that came with those hinges). Make sure the hinges are fluted enough in the curved part that they won't hold up the cowling. Lay the cowling in place and verify that the outer surface aligns with the top and side skin surfaces. If not, grind some more; you can also bend the hinge eyes up or down a little if necessary.
  7. Drill #40 the cowling to the hinges.
  8. Mark the bottom edge trim lines. Use the reference marks on the side skins as the starting point at the rear. The manual refers to some trim lines on the cowling bottom edges. These are very hard to see but they are there. Don't cut on those lines; use them only as a reference to keep your line straight and level. You should actually try to cut off as little as possible of the top cowling as necessary to get a straight edge all the way around it. Leave the cowling off when finished.
  9. Cleco on the forward bottom skin just a few places along the side and right in the center at the firewall. Mark the trim reference line on it.
  10. Trim the bottom cowling to clear the gear legs for the RV-6. For the RV-6A trim out an area almost as wide as what you will remove later when you install the air scoop but only go forward enough to allow the cowling to clear the nosewheel leg and mount. For the RV6 trim to the same width but go forward only about 5" for now; this provides access to clamp the cowling to the bottom hinges without making the cowling too floppy to handle easily.
  11. Clamp the cowling in place to the side skins and to the spinner bulkhead with the 1/8" spacers and mark reference lines on it and the spinner bulkhead. Mark the rear trim line just along the bottom and around the corners; not up the sides. Remove the cowling and trim it. Clamp it back in place against the bottom hinge eyes and mark the sides for trimming. Remove and trim.
  12. Attach the cowling hinge halves to the firewall hinge halves with the proper hinge pins. Trim the cowling to fit properly. Drill it #40 to the bottom hinges only. The radius of the corner of the cowling will probably not match that of the forward bottom skin; if not, heat up the cowling in the corners and modify the radius (but it might be easier just to use Bondo to reshape the radius). Then drill the cowling to the side hinges.
  13. Set the top cowling down on and overlapping the bottom one and use it to mark and trim the top of the bottom cowling. Trim a little at a time until the top and bottom halves mate properly. Remove the top cowling.
  14. Remove the pin and cut the hinge pieces that will join the top and bottom cowling halves out of the long piece of hinge. Cut the pin in half. Drill the hinge halves to the top of the bottom cowling. Attach the top half hinges to the bottom halves with the pins. Set the top cowling back in place and drill it to the top half of the hinges. Remove the top cowling by pulling the clecos.
  15. Finish shaping the hinge pins at the front to provide a means to lock them in place. See the construction manual for ideas. Another variation is to trim a little off both the top and bottom cowling and bend the pin so that it follows the cowling contour in this gap all the way around the front and back into the air inlet where the end can be bent and held with a screw or just stuck into a plate-reinforced hole in the cowling. Make sure any bends made are not very sharp and you do not nick the pin during bending; otherwise the pin will break under the heavy vibration experienced in this area. The fanciest method is to make the pins removable from inside the cockpit so that nothing is seen from the outside.
  16. Make and install the hinge pieces that hold the top and bottom cowling halves together just aft of the spinner. Be sure you use the special hinge with the eyes that are solid, not bent over. There is a lot of force and vibration in this area so make it strong. You may prefer to do this area with a plate riveted to the bottom cowling and nutplates on it to attach the top half. It is easy to get screws in and out in this area with a stubby screwdriver. You must always install the screws tightly with a countersunk washer to avoid having the holes in the top cowling elongated in flight.
  17. Remove both cowlings. Bond and rivet all the hinge halves to the bottom cowling and just the bottom edge hinges to the top cowling (not the ones at the firewall). Join the top and bottom cowling halves with the hinge pins. Work these pins in and out of the hinges or spin them with a drill until they move reasonably freely. Rather than making an exact cone point on the pins, make the point offset since the hinge is curved. If they go in and jam up suddenly at some point look for a hinge eye that has been distorted by the riveting operation. Polish them with a scotchbrite pad or very fine sandpaper. Coat with light oil or a dry lubricant.
  18. Make the final hinge pins for the sides of the bottom cowling out of the steel pin that was supplied with the kit. Work these pins as above to make them go in and out more easily. Bend the top of the pins over to make a handle to pull. The softer pins that came with the hinges are used on the bottom of the cowling. For now these pins are left long and straight. Put the bottom cowling back on the fuselage.
  19. Install the inlet ducts in the top cowling as shown in the manual SK-101. With the top cowling off drill holes for the clecos. After applying the adhesive, you can pop-rivet the front ends on, put the cowling in place, drill new cleco holes in the rear of the ducts through the original holes in the top of the cowling (the duct will have shifted when you installed the cowling), put in the clecos, and let the adhesive start to set up. Pull the clecoes out as soon as the adhesive is firm enough to hole the ducts. Later you can smooth out the front end and fill the cleco holes with Bondo.
  20. Make the access door for the dip stick and top hinge pins in the cowling top as shown in the construction manual. If the finger-operated latches offend you, buy the screwdriver-operated fasteners. Leave the top cowling off when finished.
  21. Mount the carburetor air box mount plate/top plate assembly to the carburetor and push the air box onto the top plate. Cut out the bottom cowling some more as necessary to allow this. Place the air scoop on the bottom cowling such that the front end is centered laterally on the cowling, there is adequate clearance between the inside of the scoop and the air box (at least 1/2"), and the contour of the scoop closely matches that of the bottom of the cowling. This should result in the rear of the scoop being about centered on the fuselage also; the scoop has a bulge to accomodate the offset carburetor placement. The rear of the scoop will probably overhang the rear of the cowling by about 1". If necessary, rough trim a little off the nose of the airbox to allow the scoop to be properly located. Mark the outline of the scoop on the cowling.
  22. Remove the cowling and set it upside down on the floor. Line up the scoop with its outline and drill the scoop #40 to the cowling at about 3" intervals. Trim off the cowling around the scoop inside edges as described in the airbox and construction manuals. Do not bond the scoop on yet.
  23. If you are building an RV-6A cut a slot right in the center of the scoop just wide enough to clear the nose gear leg. It will have to be about 14" long to start. The gear leg will be in the way of getting the lower cowling on and off easily. Remove the air box from the carburetor and lengthen the slot in the scoop until you can get the cowling on and off. The spinner rear bulkhead should be in place for this. The forward edge of the slot needs to be rounded. You can enlarge the slot a little to the side if you didn't get it properly centered. That part of the slot behind the gear leg needs to be widened to 1 1/4" to accomodate the rear hold-down to be installed later. The width and shape of the slot at and forward of the leg is not critical; you will finish it later.
  24. Attach the airbox to the carburetor and see if you can still get the cowling on and off with the spinner rear bulkhead in place. If not, you can shorten the nose of the airbox and/or lengthen the RV-6A scoop slot. The nose of the air box will be about 1 1/4" back from the rear edge of the air intake hole in the scoop at this point.

Remove the scoop from the cowling.
  1. Attach the bottom cowling to the fuselage. Cleco on the scoop and note whether the centerline of the airbox nose points directly at the center of the airscoop opening. If not, loosen the tape holding the airbox mount plate to the top plate and shift the direction of the nose as described in the Air Box Alignment section of the air box manual.
  2. At this point I found that I could not continue with the airbox construction exactly as described in its instructions. Because of the angle of the airbox nose with respect to the centerline of the fuselage the predrilled outer bolt holes in the VA-131-C mounting plate were not in a good location for attaching it to the VA-131-B top plate or for holding the filter retaining clips. Also, in one area there was not enough overlap of the two plates to allow holes to be drilled in more correct locations. There were three solutions I could think of. One was to drill the six bolt holes in the VA-131-B top plate in the proper locations (four need to be the right distance from the edge of the large opening so that the filter retaining clips will overhang the opening just a little), then make a new larger VA-131-C mount plate drilled using the top plate as a template. Another was to use the existing mount plate but drill new bolt holes; one of the holes would almost or completely miss the mount plate because the edges of the two plates did not overlap enough. In my case the edge of the bolt head still caught the edge of the mount plate so this worked but it looked unprofessional. The third was to rivet the top plate to the mount plate and use screws rather than rivets to attach the fiberglass air box to the top plate. This offers two advantages for filter servicing; a screwdriver can be used to remove the air box easily whereas a wrench is required to gain access to the filter with the first two methods, and you do not have to touch the carb heat system connections. If this method is used, metal countersunk washers must be used with the screws to avoid having vibration enlarge the holes in the fiberglass box. It is not essential that a lot of screws be used since small gaps in the seal will not affect air pressure inside the box. This method cannot be used with the RV-6A because the nose gear leg is in the way and you cannot get the airbox on over the filter without knocking it loose from the retaining clips and you can't get the filter back in the right position with the box in place.
  3. Finish the airbox and its seal to the air scoop as described in the instructions. To make this easier do a final trim of the nose of the airbox at an angle to the top plate centerline so that it is perpendicular to the centerline of the fuselage when installed. If you are planning to fly IFR in cold conditions you may not get enough carb heat with the air box pulling in engine compartment air as described in the instructions. An approach at low power will result in the engine compartment air cooling off to just a few degrees above outside air. Modify the air box to accept air from an exhaust heat muff instead. This will require attaching a hose connector to the air box nose and changing the door operating mechanism. Vans sells a 2" tube flange (part number VENT DL-03) that can be used. For this, make only a 2" opening in the top plate and make a long slot in the plate to allow the door actuator arm to extend through it. The actuator must attach to the bottom of the door rather than the top so that the door will swing all the way up.
  4. Bond the scoop to the cowling as described in the manual. You can grind off the outer edge of the scoop to a feather edge before attaching if you desire so you will not have to do much finish work at the joint.
  5. Sand the surface of the cowlings to remove the weave marks so they won't show after painting. You won't see these until you begin to sand and look at the cowling in a direct light. Also sand off almost all of the white surface at the front around the sharp bends. This is gelcoat; it is quite brittle and cracks easily. Coat any areas where the gelcoat has been removed with a primer that fills; these areas are likely to have a lot of pinholes that will show through paint. Also, be sure to seal the edges with primer as moisture can get in and cause the edges to swell.

Engine Cooling Baffles
  1. The plans show how to cut all the pieces used to make the cooling baffles for the engine so you can make your own. I recommend buying the baffle kit from Van's instead; all the pieces are already cut approximately to size and all the bends are done. Also, the baffle kit includes all the unique hardware required. Constructing the baffle system must be taken very seriously; the vibration it experiences is intense and any sloppines will lead immediately to cracks and failure.
  2. Van's baffle kit uses the top cowling as the top of the airbox; if you are really ambitious you can design and build your own baffle system that has a top as part of it and does not require the air to make any sharp turns. If done right you can decrease your cooling drag and gain a few miles per hour in top speed.
  3. The directions that come with Van's baffle kit are fairly complete, but as always some things are out of order and you need to read the whole thing through a time or two before starting. In spite of what the directions say about compatibility, expect to have to trim some parts to make them fit right. Also expect that some parts will not be trimmed quite like the drawings show.
  4. Be very careful in locating holes for rivets especially in the front area where several pieces come together as you can easily come out with a situation where it is impossible to drive some of the rivets.
  5. It is practical to mount an oil cooler on the rear baffle on the left side as is done in some factory airplanes. The cooler that Van's sells will fit here. If you do this, be sure to strongly reinforce this area or the engine vibration together with the heavy cooler will shake the baffle system to bits.

Landing Gear Finishing
At this point if you have left the forward bottom skin loose so you can more easily work in the forward part of the cockpit it will be easier to get in and out if you raise the fuselage up by installing the landing gear. In the -6 this is no problem; just pick up the front end by the engine with a hoist and insert the gear legs. In the -6A it is a bit more work.

Nose Gear on the -6A
  1. Remove any support you had under the rear of the fuselage and lift up the front by the engine far enough that you can turn the gear leg over in its normal position. Install the bolt that holds it to the engine mount (it will not have to be removed after this).
  2. Attach the fork to the gear leg as shown in drawing #62. The two disc springs U-611 are placed so that only their outer edges touch. Tighten the castellated nut until the proper force is required to move the fork as described in the construction manual. Drill the gear leg for the cotter key that will hold the nut and install the cotter key.
  3. Assemble the tube, tire, and wheel, making sure you do not pinch the tube between the wheel halves. Inflate the tire.
  4. Assemble the wheel to the fork as shown in the drawing. You may find that it will not go in because the U-610 spacers stick out too far. You can shave them down, but note that as you tighten the bolt the fork is supposed to push the U-610 spacers against the wheel bearings and the U-609 axle is not supposed to be hit the fork. This way tightening the bolt will force the tapered wheel bearings inward and seat them securely.
  5. The way to tighten the bolt is to tighten the nut until the wheel no longer spins freely, back the nut off some, then tighten it again just until the wheel will only go around about three times when you spin it as hard as you can. This takes up all the play in the wheel bearings. Do not tighten the nut on the bolt for now.
  6. Make the nosewheel fairing as described in the construction manual. It will probably be necessary for you to cut a hole in the bottom of the nose section of the fairing to clear the bottom of the gear leg. Make a fiberglass dome to cover the hole. You can permanently install the fairing at this time or wait until you have painted it. For now, leave the wheel installed.
  7. Make the fairing and wooden reinforcement for the leg. Oak is the best wood to use for this as it provides the best dampening in case of poor landings. The least finish work will be required and the most crack-resistant structure will be obtained if you cut a single piece of fiberglass cloth large enough to extend the full length of the leg and go around it at least four times. Glue the wooden stiffener pieces together, then glue this to the leg. When set up, staple the edge of the cloth to the stiffener. Finish the fairing by wrapping the cloth around the leg three times applying resin as you go. Pull the cloth tight directly to the rear using the excess cloth clamped between two sticks as a handle until the resin begins to set up. A hair dryer will speed this up.
  8. Smooth out the fairing by adding another coat of resin and sanding it down. Make the fairing at the top between the leg and the cowling by installing the cowling, covering the bottom side around the leg hole with packaging tape, and builing up a fairing with Bondo or Microballoon filler. The top edge of the fairing should not be larger than the opening in the cowling so that the cowling can drop down for removal.

Main Gear on the -6A
  1. Make a sawhorse out of 2x4's that is 36 inches long and 28 inches high. Pad the top with about one inch of very stiff foam rubber.
  2. Attach an engine hoist to the engine mount as far back as you can (the crossbar behind the engine is OK) with a rope or fabric sling and lift up the front a few inches. This is essential to keep the fuselage from falling over while you raise the rear and it also makes the rear a little easier to lift. Work the sawhorse under the fuselage starting at the rear and move it forward until you get it right under the baggage compartment rear bulkhead F-606. Adjust the height of the engine hoist so that some but not all of the engine weight is supported by the hoist.
  3. Remove the old support legs from the wooden temporary spars.
  4. Install the landing gear mounts using at least four bolts each and non-locking nuts through the wooden spar substitute. The bolts and screws holding the mounts to the side of the fuselage can be permanently installed now.

Main Gear Mounting, -6 and -6A
  1. Put the gear legs in place temporarily. It may be necessary to tilt the fuselage a little on the -6A to start the legs into the mounts.
  2. Mount the brakes, wheels, fairing support, and wheel fairings to the legs as described in the construction manual and drawing #57. The brake caliper is mounted with the caliper to the rear, the bleed valve pointing down, and the main body inboard. Remove the two bolts holding the caliper assembly together to take the wheel on and off. Your plans may show an AN5-17A bolt attaching the brake attach flange to the gear leg. A bolt head is too large to work here so Van's supplies an allen-head screw instead and this is included with more recent kits. Some gear legs were made too large so that the wheel bearings will not fit on them. Sand down the legs just enough that the bearings will go on without forcing. Cut a fairly generous section out of the inside of the wheel fairing to allow it to be placed over the gear leg; this area will be rebuilt later to fair it to the gear leg fairing.
  3. Make the section of brake line that goes up the leg to the fuselage and tape it in place.
  4. Make the gear leg stiffeners and fairing. The aluminum fairings provided in the kit are easy to build but you can make fairings out of fiberglass with a lot more labor that look better if you get closer than three feet. With the aluminum fairings you can replace the brake line later if you have to. To do the aluminum fairings, attach the wooden stiffeners to the rear of the gear leg using at least three layers of fiberglass cloth and then sand off any big bumps (the aluminum fairings fit tight and any bumps will show through). Paint a smooth layer of resin over the leg so that the aluminum fairing will not be worn through by the leg as it flexes.
  5. Run the brake line up the front of the leg and tape it in place. Connect the tube to the elbow on the fuselage side. Make sure you do the loop of the tubing at the lower end around the bottom of the axle and back up to the brake cylinder as shown in the construction manual so that activation of the brake will not flex the tubing very much at any one place.

Wing Mounting
Fitting the wings to the fuselage should be the last thing you do before taking it to the airport if you are working at home. The idea is to have as little left to do as possible when you take it to where working on it is less convenient. Almost all of the wing mounting tasks can be done in a two-car garage or similar space if necessary by a process involving doing one wing at a time. Since it is not possible to set the wing sweep accurately with only one wing installed you cannot drill the front and rear attach bolt holes or the fuselage skin-to-wing holes. You can make the wing root fairings and install the nutplates for them on the wing but figure that you will have to trim the inboard edge after final placement of the wings.

Wingtip Mounting
  1. You are now ready to assemble the wingtip rib to the wingtip, build in whatever lighting you plan, and install the tip on the wing. You may want to make the wingtip removable if you expect to try to use wingtip antennas or install strobe light power supplies in the wings. If you bond it on, it is useful to place the wingtip position light fixture in line with the largest (forward) lightening hole in the main rib so you can install or pull out the aileron push rod without removing the wing.
  2. With the wing on the fuselage, in a cradle, or on a cart, install the aileron with temporary bolts and nuts but using the right washers and spacers. Fix the aileron in the neutral position.
  3. Clean all the excess gelcoat out of the indented edge of the wingtip. Measure on the wing the maximum depth that the tip can go in and trim the edge of the tip if necessary to insure that it will go far enough in that the wing skin completely covers the indentation for it. Stuff the tip with foam rubber scraps or newspapers as necessary to make it slightly fatter than the end of the wing. Hold the tip up to the wing, see where it hits the aileron brackets and trim the tip to clear them. Also trim to leave approximately 1/4" between the wingtip and the aileron.
  4. Insert the wingtip rib into the wingtip with the flange side out and flange edges about 1/4" inward from the wingtip edge (there is no right and left rib; both are the same), and shift it fore and aft until it forces the rear of the tip to have the same shape as the aileron. Drill the rib to the wingtip #40 only at the rib ends. Leave the rib clecoed in place for all the following steps so the rear edge will not curl up or down as the wingtip is forced to fit the wing.
  5. Tape several stiff wood strips to the top of the wing extending out over where the wingtip will be; these are to insure that the wingtip surface lines up straight with the rest of the wing surface. You should also verify the skin line using the airfoil template made from the side of the wing crate. Getting the wingtip to align properly on both the top and the bottom at the same time is a little tricky since there is some twist and warp in this part. It may even be necessary to split the tip at the rear and up the side a little ways and re-bond it to get it to match the airfoil shape. Put the tip in place and insure that it goes in far enough that the wing skin comes all the way to the edge of the indented area on the wingtip on top and bottom at the same time. Push the tip as far forward as possible. If its shape does not match that of the leading edge skin very well, heat up the wingtip with a hair dryer and reshape it. Drill the wingtip #30 to attach it to the top side wing skin starting at the forward end and spaced 3" apart. The drill the bottom sde starting at the front. Remove the tip.
  6. If you want to make the tip removable, make strips of .032 aluminum about 3/4" wide as backup for nutplates. Half-inch 6-32 flathead 100 degree stainless steel screws (AN507C632R-8, available from Van's) work best here. Bend the strips to match the contour of the wing and hold them in place inside the tip to drill them #30. Then mount nutplates on the strips and bond them in place inside the tip. Use screws as well as clamps to hold the strips, but pull the screws out before the adhesive has fully cured. You can use K1000 nutplates, but rivnuts (threaded inserts you install with an upsetting tool, ATA2-632 from Van's) work just as well and are much quicker to install. Countersink the wingtip holes and dimple the wing holes with a standard 1/8" flush rivet dimple die. If you are using the rivnuts, you can dimple the aluminum strips with the dies for 8-32 screws before installing them so the strip will lay flat against the inside of the wingtip.
  7. If you do not want to have the wing removable, make strips of .025 or .032 aluminum to as backup for pop rivets and bond them to the inside of the tip. When secure, drill them #30 through the holes in the tip. Countersink the holes in the tip and dimple the holes in the wing skin. Do not bond in place yet.
  8. If you plan to bond the wingtip rib in place you need only put rivets in the holes previously drilled at the ends of the ribs. If you want to use rivets, drill the rest of the rib to the wingtip #40. You can permanently install the rib now using either all flush rivets or mostly epoxy structural adhesive.
  9. The standard molded wingtips supplied with the wing kit may begin to get wavy across the top in the first summer after installation on the wing. You can purchase an improved wingtip from several sources (ask Van's who is currently selling them). You can also improve the wingtips you have by making a sandwich reinforcing area on the inside of the top; use polyester resin (not epoxy) and fiberglass cloth over a 3/16" thick by 6" wide panel of balsa wood or 1/2" rigid foam that is compatible with the resin. The grain of the balsa wood should run fore and aft. To start, put resin on the inside of the top of the wingtip and put the balsa wood or foam in it. Stuff the tip with foam rubber tight enough to force the wood or foam to conform to the shape of the wingtip and attach the tip to the wing. When this sets up, finish with couple of layers of glass and resin.

Navigation Lights
  1. Most bulders seem to prefer the three-way wingtip lights; red/green forward, white aft, and strobe all in the same fixture, with a power supply in each wing mounted on the outboard rib. This meets the FAA requirements and requires the least work because no other lights are needed. The reason for using the more expensive dual power supplies is that you will not have a long run of wire carrying the noise-generating pulse of current to the flash bulbs; this could interfere with navigation radios but so far I have not heard from anyone who actually had a problem with this. The light fixture must be mounted out far enough that the colored and white lights will be visible from straight forward and straight back. The strobe lights must be visible upward and downward also.
  2. To mount these lights you can buy a molded mount from several sources including Van's or make your own. The advantage of Van's is that it can easily be mounted flush with the wingtip surface so that almost no finish work is required. To make your own mount, make a solid mount out of modeling clay, using a little water on your fingers at the last to help make the surface smooth. Bake the mold just enough to dry it out good. Use that to make a female mold out of clay. Make an aluminum mounting plate the same size as the base of the light fixture and attach nutplates to it to allow easy removal of the light fixture later. If you are bonding on the wingtip the hole in the plate should be large enough for the aileron push rod to go through (1 1/4" diameter). Make the mounting platform for the fixture by laying up several layers of fiberglass and resin in the mold, with the mounting plate on the inside. You can also just lay fiberglass on top of the clay mount you made to form the final mount but this may actually take longer in finishing the outside surface.

finish.doc 4/13/96 by Frank Justice

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