---------------------------------------------------------- Kitfox-List Digest Archive --- Total Messages Posted Sun 01/23/11: 19 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:14 AM - Re: Composites and mold work (WurlyBird) 2. 02:53 AM - Re: Kitfox-List Digest: 8 Msgs - 01/22/11 (great bear) 3. 03:48 AM - Re: Re: Composites and mold work (Lynn Matteson) 4. 06:37 AM - Re: Re: Composites and mold work (Lynn Matteson) 5. 06:49 AM - Re: Re: Composites and mold work (Noel Loveys) 6. 07:03 AM - Re: Re: Composites and mold work (Noel Loveys) 7. 07:27 AM - Re: Re: Composites and mold work (Lynn Matteson) 8. 08:39 AM - Re: Composites and mold work (Guy Buchanan) 9. 09:03 AM - Re: Re: Composites and mold work (Patrick Reilly) 10. 10:10 AM - Re: Re: Composites and mold work (Lynn Matteson) 11. 10:17 AM - Re: Re: Composites and mold work (Michael Logan) 12. 10:25 AM - Re: Composites and mold work (Lynn Matteson) 13. 02:55 PM - Re: Kitfox-List Digest: 8 Msgs - 01/22/11 (EMAproducts@aol.com) 14. 03:35 PM - Re: Re: Composites and mold work (Noel Loveys) 15. 04:13 PM - Re: Re: Composites and mold work (Noel Loveys) 16. 04:51 PM - Re: bleed problem (jridgway) 17. 06:48 PM - Re: Re: Composites and mold work (Lynn Matteson) 18. 08:22 PM - 582 throttle cable (369PL) 19. 09:04 PM - Re: Re: Kitfox-List Digest: 8 Msgs - 01/22/11 (Lowell Fitt) ________________________________ Message 1 _____________________________________ Time: 12:14:25 AM PST US Subject: Kitfox-List: Re: Composites and mold work From: "WurlyBird" Good point Guy, I completely forgot to mention the TOOL factor (not me, the actual tools). I am always collecting more tools, it drives my wife crazy. I always claim I can build something for less then it can be bought, of course I never factor in all the tools I don't yet have to that cost. One day though, I will have all the tools I need :D -------- James Kitfox 3 / 582 / 70" IVO 2 blade GA 50 hrs on the Fox in between deployments, now she lies in wait Read this topic online here: http://forums.matronics.com/viewtopic.php?p=327979#327979 ________________________________ Message 2 _____________________________________ Time: 02:53:54 AM PST US From: great bear Subject: Kitfox-List: Re: Kitfox-List Digest: 8 Msgs - 01/22/11 A followup on vacuum bagging and heating fiberglassfor curing...There is a lot of structural work in building a Glasair...I never vacuum bagged any part...everything was hand layed two or three layers at a time...as long as the room temps was close to 60- 70 degrees the glass would cure to sandable over night so there was no need to heat anything if ambient was close to that range....most builders (including myself) would wait for a cool day ( 45-50) to layup big stuff like the wing spars and major assemblies so that the working time and pot life would be long enough to make adjustments, but keep in mind the cure time would be days for those parts under those conditions but the bond would be just as strong..and heat the room...not the parts if you must...it seems like there is many approaches to this subject but I definitely agree that vacuum bagging parts is a waste of material and time for the projects we are doing...if you were building one of rutans space planes or 50 foot windmill props I could see a reason....but fuel tanks and speedcuffs, cowling..little fairings....not worth the time and extra material..west epoxy is almost clear so it works great if your going to leave parts natural..best stuff I have used so far...I didnt start out with that system but once I found out about it I wouldnt recommend anything else so far.......Gary ..,,,,,KF5 Outback.0-200 at 80%....Glasair 1TD flying... and Cessna 170A (My daily driver) ________________________________ Message 3 _____________________________________ Time: 03:48:59 AM PST US From: Lynn Matteson Subject: Re: Kitfox-List: Re: Composites and mold work OK, if the part being built is a flat instrument panel, then no bag is required. Just lay out your shape on a plate of glass. The glass side will be the outside of the panel. You probably won't even have to wax it. By the way, I bought and used the mold release wax, and the spray-on release compound, and they both work fine, but so did the Johnson's Paste Wax that I have used prior to buying the "professional mold releases"...and a lot cheaper, too. A friend of mine made a very nice clip board using carbon fiber which he laid out on glass and it came out looking super...very smooth, because he squeeged the excess resin off the layup, and used the glass side as the front surface....a sheet of nylon or plastic works too. Lynn Matteson Kitfox IV Speedster, taildragger Jabiru 2200, #2062 Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives Electroair direct-fire ignition system Rotec TBI-40 injection Status: flying...1078+ hrs (since 3-27-2006) On Jan 22, 2011, at 2:23 PM, WurlyBird wrote: > > > > Lynn Matteson wrote: >> see if you really need to "bag >> it" or if it just sounds like a really cool thing to do....like I >> did. : ) > > > C'mon, we are talking about not structural parts for a Kitfox. It > is not necessary to use composites at all much less vacuum > bagging. It is definitely because it sounds like the cool thing to > do. :D I have a tendency to have visions of grandeur with my > projects, especially sitting here in a crappy country dreaming > about it for a year! I have been interested in vacuum bagging for > as long as I have understood what composites are good for. I keep > adding to my "wish list" at Aircraft Spruce and it certainly costs > noticeably more to bag anything. I am also trying to figure out > how much I will actually use the system as it is only NEEDED for > one idea I have right now and all I have come up with besides > making the occasional part is using it to instantly marinate > meats. I can hear it now; > > friend- "What is James doing in the garage?" > wife- "Marinating the chicken." > now confused friend- "With an air compressor?!?!" > > [Shocked] > > -------- > James > Kitfox 3 / 582 / 70" IVO 2 blade GA > 50 hrs on the Fox in between deployments, > now she lies in wait ________________________________ Message 4 _____________________________________ Time: 06:37:16 AM PST US From: Lynn Matteson Subject: Re: Kitfox-List: Re: Composites and mold work I can NEVER pass up a new tool...especially if it's high on the "cool tool" barometer. : ) Hell, I've got some cool tools that are so beyond my personal (used once) usage, that I have to use them on my CFI' s airplanes just to *justify* their purchase. By the way, when I was waiting for the air compressor-powered vacuum bagging kit to arrive, I made do with a vacuum cleaner just to run a test sample of bagging. It worked, but who wants to listen to the vacuum cleaner run for hours...certainly not the dog! : ) Lynn Matteson Kitfox IV Speedster, taildragger Jabiru 2200, #2062 Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives Electroair direct-fire ignition system Rotec TBI-40 injection Status: flying...1078+ hrs (since 3-27-2006) do not archive On Jan 22, 2011, at 11:48 PM, Guy Buchanan wrote: > > On 1/22/2011 9:59 AM, Lynn Matteson wrote: >> By the way, I bought my kit when I was thinking of using it to >> make a pair of skis, then went in another direction. I will finish >> the vacuum pump one of these days, and then actually use it, but >> the cost of the supplies that are scrapped during its use should >> justify the use. If you can make the part light without bagging, >> that part will be a lot cheaper. > > HAHAHAHAHA! C'mon Lynn. When did ANYTHING in aviation get justified > on a cost basis. We do it because it's COOL. Way COOL. (Besides, > who can pass up an opportunity to get more tools.) > > Guy Buchanan > Ramona, CA > Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded > > ________________________________ Message 5 _____________________________________ Time: 06:49:29 AM PST US From: "Noel Loveys" Subject: RE: Kitfox-List: Re: Composites and mold work Most if not all commercial parts are cured in an autoclave. They use vacuum inside the bagging and pressure outside with of course heat. The heat is required to make the Layup cloths cure. Without the heat the cloth can actually never properly cure. Noel -----Original Message----- From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Guy Buchanan Sent: January 22, 2011 12:28 PM Subject: Re: Kitfox-List: Re: Composites and mold work On 1/21/2011 9:51 PM, WurlyBird wrote: > Does heating the resin while it is curing cause it to more thoroughly cure? From the way you phrased it it sounds like if you expect your part to be exposed to 200 deg in use then it should be baked at a minimum of 200 deg during build up, is this about right? Perfect. > Joe Woodworker has designed and has free plans for venturi style vacuum press and vennersupplies sells the kit. This set up has the benefit of having a vacuum reservoir that can easily be made a little larger and even as published should be great for dash sized projects. > I did the verturi thing once and it required an ENORMOUS amount of air which I didn't have. I got a surplus vacuum pump instead. Guy Buchanan Ramona, CA Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded ________________________________ Message 6 _____________________________________ Time: 07:03:20 AM PST US From: "Noel Loveys" Subject: RE: Kitfox-List: Re: Composites and mold work Vacuum bagging results in very strong light parts when done properly. There is another problem with bagging and that is the possibility of voids inside the part which you can only find with ultrasound or industrial X-ray. Even the commercial composite companies spend a lot of time checking each and every part they make looking for weaknesses and voids. For repair work there is a machine available, called a Hot Shot, which comes in a suitcase. It has hoses, sniffers and a heat blanket in the case to cure Pre-Preg cloth. Don't ask how much! Noel -----Original Message----- From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteson Sent: January 22, 2011 2:29 PM Subject: Re: Kitfox-List: Re: Composites and mold work I bought the air compressor-powered vacuum bagging kit and have yet to finish the completion of the pump. I got mine over a year ago, after seeing one that a friend built from one of He likes the way it works, but cautioned me that using the bagging system....any bagging system....is very costly in materials. He said that the raw materials used up and thrown away counts up, and he found that he doesn't use his bagging method as much since he discovered that. Just be aware of the cost of doing vacuum bagging, and see if you really need to "bag it" or if it just sounds like a really cool thing to do....like I did. : ) By the way, I bought my kit when I was thinking of using it to make a pair of skis, then went in another direction. I will finish the vacuum pump one of these days, and then actually use it, but the cost of the supplies that are scrapped during its use should justify the use. If you can make the part light without bagging, that part will be a lot cheaper. Lynn Matteson Kitfox IV Speedster, taildragger Jabiru 2200, #2062 Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives Electroair direct-fire ignition system Rotec TBI-40 injection Status: flying...1078+ hrs (since 3-27-2006) On Jan 22, 2011, at 12:51 AM, WurlyBird wrote: > > > Thanks for the great information. Here is the first followup > question. > > What does baking a composite part do to the build up? > > Does heating the resin while it is curing cause it to more > thoroughly cure? From the way you phrased it it sounds like if you > expect your part to be exposed to 200 deg in use then it should be > baked at a minimum of 200 deg during build up, is this about right? > > I do plan on leaving some of the parts natural. If I get the HKS > when I get home I am going to need a new instrument panel and I > figure it might as well be carbon or carbon/kevlar. Light, > functional, and sexy, you cant beat it. With the Kitfox being as > low tech and old school as it is, I anticipate that the carbon on > the dash will look a little out of place so there will need to be a > little carbon here and a little there just to balance it out > aesthetically. I am conceiving a part that will be a LOT of sharp > corners but I plan on getting into bagging and maybe even > infusion. If the part I have in my head works out I will be > telling you all about it, until then it is hush hush. > > In case anyone else has been toying with the idea of bagging but > can not find a reasonable set up, check this out: > > http://www.veneersupplies.com/ > http://www.joewoodworker.com/ > > Joe Woodworker has designed and has free plans for venturi style > vacuum press and vennersupplies sells the kit. This set up has the > benefit of having a vacuum reservoir that can easily be made a > little larger and even as published should be great for dash sized > projects. > > -------- > James > Kitfox 3 / 582 / 70" IVO 2 blade GA > 50 hrs on the Fox in between deployments, > now she lies in wait > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=327856#327856 > > ________________________________ Message 7 _____________________________________ Time: 07:27:00 AM PST US From: Lynn Matteson Subject: Re: Kitfox-List: Re: Composites and mold work Noel- Using the terms "layup cloths" and "the cloth can never properly cure" sounds like you're referring to "pre-pegs", right? I just never figured the pre-pegs were in my league for the parts that I was looking to make, let alone an autoclave. By the way, the ski "spats" that I just made (to keep the snow off the airplane's skis) were laid up over Poly-fiber fabric, which was painted with a spray can (just to seal the weave of the fabric, waxed with mold release wax, then sprayed with PVA release film. I applied the Polyfiber fabric over the skis, tightened it down, painted it and went to work with the fiberglass....e-glass, that is. Two layers of this came out to 28-32 thousandths thick, and strong. The resulting spats weigh about 20 ounces each. I just wish the skis were relatively light as well....that'll come next. Lynn Matteson Kitfox IV Speedster, taildragger Jabiru 2200, #2062 Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives Electroair direct-fire ignition system Rotec TBI-40 injection Status: flying...1078+ hrs (since 3-27-2006) On Jan 23, 2011, at 9:39 AM, Noel Loveys wrote: > > Most if not all commercial parts are cured in an autoclave. They > use vacuum > inside the bagging and pressure outside with of course heat. The > heat is > required to make the Layup cloths cure. Without the heat the cloth > can > actually never properly cure. > > Noel > > -----Original Message----- > From: owner-kitfox-list-server@matronics.com > [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Guy > Buchanan > Sent: January 22, 2011 12:28 PM > To: kitfox-list@matronics.com > Subject: Re: Kitfox-List: Re: Composites and mold work > > > On 1/21/2011 9:51 PM, WurlyBird wrote: >> Does heating the resin while it is curing cause it to more thoroughly > cure? From the way you phrased it it sounds like if you expect > your part to > be exposed to 200 deg in use then it should be baked at a minimum > of 200 deg > during build up, is this about right? > Perfect. >> Joe Woodworker has designed and has free plans for venturi style >> vacuum > press and vennersupplies sells the kit. This set up has the > benefit of > having a vacuum reservoir that can easily be made a little larger > and even > as published should be great for dash sized projects. >> > I did the verturi thing once and it required an ENORMOUS amount of air > which I didn't have. I got a surplus vacuum pump instead. > > Guy Buchanan > Ramona, CA > Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded > > ________________________________ Message 8 _____________________________________ Time: 08:39:41 AM PST US From: Guy Buchanan Subject: Re: Kitfox-List: Composites and mold work On 1/23/2011 2:51 AM, great bear wrote: > I definitely agree that > vacuum bagging parts is a waste of material and time for the projects we are > doing...if you were building one of rutans space planes or 50 foot windmill > props I could see a reason....but fuel tanks and speedcuffs, cowling..little > fairings....not worth the time and extra material.. Hi. Would you please put your full name, location and aircraft type / status in your signature line? We, the moderators, find it makes for a much more congenial atmosphere. Thanks. Regarding vacuum bagging. It is far more expensive but I recommended it based on a suggestion of sharp corners in the part. There's no way to get female corners sharp in a contact laminate, and male corners are deucedly hard. (Though it can be done with some crude tooling.) Glasairs and Lancairs and most other composite kit aircraft were designed very carefully to avoid vacuum bagging, with all the sharp corners in the provided kit parts. Guy Buchanan - List moderator Ramona, CA Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded ________________________________ Message 9 _____________________________________ Time: 09:03:21 AM PST US Subject: Re: Kitfox-List: Re: Composites and mold work From: Patrick Reilly James, The problem is once you have that many tools you either can't find them or can't remember if you have a specific tool. Hell, I got divorced 11 years ago, and sold virtually all my tools at that time. In the last 6 years I once again have accumulated a hanger and a garage full of tools, often duplicated because if I need it at home the tool is at the hanger and visa versa. By the way has anybody got an auto lift for sale. When I buy the hanger next to mine I have it figured out how I can install it and still get 2 planes in. I have a stick welder, wire welder and acyletlene set up. But, I still need a TIG unit if you have one you aren't using.....HA It's an addiction! But, I have been able to resist ever buying vaccume bagging equipment. And researching what vaccume bagging takes, I'll stick with West System products and hand layup. Pat Reilly Mod 3 582 Rebuilt Rockford, IL On Sun, Jan 23, 2011 at 2:12 AM, WurlyBird wrote: > james.t.trizzino@us.army.mil> > > Good point Guy, I completely forgot to mention the TOOL factor (not me, the > actual tools). I am always collecting more tools, it drives my wife crazy. > I always claim I can build something for less then it can be bought, of > course I never factor in all the tools I don't yet have to that cost. One > day though, I will have all the tools I need :D > > -------- > James > Kitfox 3 / 582 / 70" IVO 2 blade GA > 50 hrs on the Fox in between deployments, > now she lies in wait > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=327979#327979 > > -- Pat Reilly Mod 3 582 Rebuild Rockford,IL ________________________________ Message 10 ____________________________________ Time: 10:10:09 AM PST US From: Lynn Matteson Subject: Re: Kitfox-List: Re: Composites and mold work The West System 5:1 pumps are great, too...IF that's what the ratio needs to be....but I use a way to make less than the 1-ounce of mix that one stroke of the pumps puts out. It's no big deal, but if you need, say, a partial ounce to finish up a job, or just a small job that will need less than an ounce, just use two equal-size cups on the balance scales...one on each side...and put a 10-32 nut in one cup and *carefully* pump hardener until the scales balance again. Then add 5 nuts of the same size and pump the resin until the scales balance again...simple math/physics, and you've cheated the waste basket of some otherwise wasted epoxy. Lynn Matteson Kitfox IV Speedster, taildragger Jabiru 2200, #2062 Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives Electroair direct-fire ignition system Rotec TBI-40 injection Status: flying...1078+ hrs (since 3-27-2006) On Jan 23, 2011, at 11:54 AM, Patrick Reilly wrote: > James, The problem is once you have that many tools you either > can't find them or can't remember if you have a specific tool. > Hell, I got divorced 11 years ago, and sold virtually all my tools > at that time. In the last 6 years I once again have accumulated a > hanger and a garage full of tools, often duplicated because if I > need it at home the tool is at the hanger and visa versa. By the > way has anybody got an auto lift for sale. When I buy the hanger > next to mine I have it figured out how I can install it and still > get 2 planes in. I have a stick welder, wire welder and acyletlene > set up. But, I still need a TIG unit if you have one you aren't > using.....HA It's an addiction! But, I have been able to resist > ever buying vaccume bagging equipment. And researching what vaccume > bagging takes, I'll stick with West System products and hand layup. > > Pat Reilly > Mod 3 582 Rebuilt > Rockford, IL > ________________________________ Message 11 ____________________________________ Time: 10:17:03 AM PST US From: "Michael Logan" Subject: RE: Kitfox-List: Re: Composites and mold work Chrissi and Randi of the Cozy Girrrls (http://www.cozygirrrl.com/menupage.htm) have developed a low cost vacuum bagging process that is pretty cool and does not cost much in wasted materials. I watched them makes some pieces at Sun-n-Fun last year and it really works. Mike Logan Series 5 RAM EA81 -----Original Message----- From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Guy Buchanan Sent: Saturday, January 22, 2011 11:49 PM Subject: Re: Kitfox-List: Re: Composites and mold work On 1/22/2011 9:59 AM, Lynn Matteson wrote: > By the way, I bought my kit when I was thinking of using it to make a > pair of skis, then went in another direction. I will finish the vacuum > pump one of these days, and then actually use it, but the cost of the > supplies that are scrapped during its use should justify the use. If > you can make the part light without bagging, that part will be a lot > cheaper. HAHAHAHAHA! C'mon Lynn. When did ANYTHING in aviation get justified on a cost basis. We do it because it's COOL. Way COOL. (Besides, who can pass up an opportunity to get more tools.) Guy Buchanan Ramona, CA Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded ________________________________ Message 12 ____________________________________ Time: 10:25:25 AM PST US From: Lynn Matteson Subject: Re: Kitfox-List: Composites and mold work I made a slight mistake in buying a DVD of a fiberglass project that some students were doing. One of the best points that I took away from viewing this DVD was that the *most* important element of building a mold, or making a product, was the design of the product/ mold. You cannot have negative draft and expect to get the part out of a one-piece mold. These guys were trying to get a spherical-shaped part out of a mold, and later realized that the mold must be split at the widest part of the part, thus eliminating any negative draft in either of the two parts of the mold. Maybe the male/female corners could be done this way, eh? I was taught in Fiberglass 101 (actually an EAA weekend course) to make up a slurry of resin and filler (filler type depending on the application) to use in sharp corners....sometimes after the part was laid up and cured. Lynn Matteson Kitfox IV Speedster, taildragger Jabiru 2200, #2062 Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives Electroair direct-fire ignition system Rotec TBI-40 injection Status: flying...1078+ hrs (since 3-27-2006) On Jan 23, 2011, at 11:21 AM, Guy Buchanan wrote: > > On 1/23/2011 2:51 AM, great bear wrote: >> I definitely agree that >> vacuum bagging parts is a waste of material and time for the >> projects we are >> doing...if you were building one of rutans space planes or 50 foot >> windmill >> props I could see a reason....but fuel tanks and speedcuffs, >> cowling..little >> fairings....not worth the time and extra material.. > Hi. Would you please put your full name, location and aircraft > type / status in your signature line? We, the moderators, find it > makes for a much more congenial atmosphere. Thanks. > > Regarding vacuum bagging. It is far more expensive but I > recommended it based on a suggestion of sharp corners in the part. > There's no way to get female corners sharp in a contact laminate, > and male corners are deucedly hard. (Though it can be done with > some crude tooling.) Glasairs and Lancairs and most other composite > kit aircraft were designed very carefully to avoid vacuum bagging, > with all the sharp corners in the provided kit parts. > > Guy Buchanan - List moderator > Ramona, CA > Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded > > ________________________________ Message 13 ____________________________________ Time: 02:55:38 PM PST US From: EMAproducts@aol.com Subject: Kitfox-List: Re: Kitfox-List Digest: 8 Msgs - 01/22/11 Subject: Re: Kitfox-List: Re: Composites and mold work About 20 years I was doing some composite work and looking for a low cost vacuum pump. An old auto air conditioner compressor with a electric motor to turn it, hook to the inlet line with a gauge & relief valve and your vacuum is limited to the size of the electric motor driving it! I made lots of NASA inlets using it. has been over 30 years don't remember vacuum or anything else. ________________________________ Message 14 ____________________________________ Time: 03:35:13 PM PST US From: "Noel Loveys" Subject: RE: Kitfox-List: Re: Composites and mold work You're right Lynn. However not all resins will cure at room temperature. The same resins in Pre-preg are available for wet layup. They will require heat even if applied locally to cure properly. When filling cloth with resin for the greatest strength and least weight there is a ratio of cloth to resin by weight which should not be exceeded. Because the stiffness is caused by the resin and the strength is actually in the cloth too much resin or too little resin makes for a weaker part. The process I use is to fill my cloth with resin. I generally weigh the cloth and the mixed resins. Then I sandwich the cloth in clear plastic and squeegee out any excess resin. (usually not very much) Then I can put the cloth "sandwich" rolled up in a refrigerator while making more "sandwiches". When I have all the cloth I think I'll need in the sandwich from (plastic on both sides) I then start my lay up... rolling each layer of cloth into the previous layer. Doing it that way more or less insures me of two things... an efficient amount of resin in the final product and I can easily see voids as I do the layup and roll them out. When we trained in composites we generally used uni-directional cloth but we also followed a bagging schedule which laid out the direction the warp of each layer ran. Some bagging schedules had many layers of cloth. Following the schedule religiously ensured good strength in all directions. You would be amazed at the strength of a piece of composite glass or graphite two inches long and 1/8 in thick(in both directions) There is a problem with vacuum bagged composites which comes up from time to time. That is it is porous. A small insignificant nick in the finish of say a 777 cowl can be very dangerous as rain water can seep into the material through a scratch. At altitude the water freezes and the cowl can be internally forced apart by the expansion of the freezing water. A slight rub by a forklift brushing an aluminium cowl may not be of any concern. The same damage to a composite will ground the aircraft until the cowl is replaced.... bring MONEY! The crown who were specializing in composite repair (not me) used to make forms to mould on. Those Forms (plugs) were made of straw wet with some kind of plaster for the rough shape then finished with plaster of paris which can be sanded to final shape and then waxed. Noel -----Original Message----- From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteson Sent: January 23, 2011 11:50 AM Subject: Re: Kitfox-List: Re: Composites and mold work Noel- Using the terms "layup cloths" and "the cloth can never properly cure" sounds like you're referring to "pre-pegs", right? I just never figured the pre-pegs were in my league for the parts that I was looking to make, let alone an autoclave. By the way, the ski "spats" that I just made (to keep the snow off the airplane's skis) were laid up over Poly-fiber fabric, which was painted with a spray can (just to seal the weave of the fabric, waxed with mold release wax, then sprayed with PVA release film. I applied the Polyfiber fabric over the skis, tightened it down, painted it and went to work with the fiberglass....e-glass, that is. Two layers of this came out to 28-32 thousandths thick, and strong. The resulting spats weigh about 20 ounces each. I just wish the skis were relatively light as well....that'll come next. Lynn Matteson Kitfox IV Speedster, taildragger Jabiru 2200, #2062 Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives Electroair direct-fire ignition system Rotec TBI-40 injection Status: flying...1078+ hrs (since 3-27-2006) On Jan 23, 2011, at 9:39 AM, Noel Loveys wrote: > > Most if not all commercial parts are cured in an autoclave. They > use vacuum > inside the bagging and pressure outside with of course heat. The > heat is > required to make the Layup cloths cure. Without the heat the cloth > can > actually never properly cure. > > Noel > > -----Original Message----- > From: owner-kitfox-list-server@matronics.com > [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Guy > Buchanan > Sent: January 22, 2011 12:28 PM > To: kitfox-list@matronics.com > Subject: Re: Kitfox-List: Re: Composites and mold work > > > On 1/21/2011 9:51 PM, WurlyBird wrote: >> Does heating the resin while it is curing cause it to more thoroughly > cure? From the way you phrased it it sounds like if you expect > your part to > be exposed to 200 deg in use then it should be baked at a minimum > of 200 deg > during build up, is this about right? > Perfect. >> Joe Woodworker has designed and has free plans for venturi style >> vacuum > press and vennersupplies sells the kit. This set up has the > benefit of > having a vacuum reservoir that can easily be made a little larger > and even > as published should be great for dash sized projects. >> > I did the verturi thing once and it required an ENORMOUS amount of air > which I didn't have. I got a surplus vacuum pump instead. > > Guy Buchanan > Ramona, CA > Kitfox IV-1200 / 592-C / Warp 3cs / 500 hrs. and grounded > > ________________________________ Message 15 ____________________________________ Time: 04:13:14 PM PST US From: "Noel Loveys" Subject: RE: Kitfox-List: Re: Composites and mold work I gotta love that idea! Noel -----Original Message----- From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteson Sent: January 23, 2011 2:38 PM Subject: Re: Kitfox-List: Re: Composites and mold work The West System 5:1 pumps are great, too...IF that's what the ratio needs to be....but I use a way to make less than the 1-ounce of mix that one stroke of the pumps puts out. It's no big deal, but if you need, say, a partial ounce to finish up a job, or just a small job that will need less than an ounce, just use two equal-size cups on the balance scales...one on each side...and put a 10-32 nut in one cup and *carefully* pump hardener until the scales balance again. Then add 5 nuts of the same size and pump the resin until the scales balance again...simple math/physics, and you've cheated the waste basket of some otherwise wasted epoxy. Lynn Matteson Kitfox IV Speedster, taildragger Jabiru 2200, #2062 Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives Electroair direct-fire ignition system Rotec TBI-40 injection Status: flying...1078+ hrs (since 3-27-2006) On Jan 23, 2011, at 11:54 AM, Patrick Reilly wrote: > James, The problem is once you have that many tools you either > can't find them or can't remember if you have a specific tool. > Hell, I got divorced 11 years ago, and sold virtually all my tools > at that time. In the last 6 years I once again have accumulated a > hanger and a garage full of tools, often duplicated because if I > need it at home the tool is at the hanger and visa versa. By the > way has anybody got an auto lift for sale. When I buy the hanger > next to mine I have it figured out how I can install it and still > get 2 planes in. I have a stick welder, wire welder and acyletlene > set up. But, I still need a TIG unit if you have one you aren't > using.....HA It's an addiction! But, I have been able to resist > ever buying vaccume bagging equipment. And researching what vaccume > bagging takes, I'll stick with West System products and hand layup. > > Pat Reilly > Mod 3 582 Rebuilt > Rockford, IL > ________________________________ Message 16 ____________________________________ Time: 04:51:42 PM PST US Subject: Kitfox-List: Re: bleed problem From: "jridgway" GOOD LUCK...jack I FOUND THE MATCO FOLKS VERY HELPFUL. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=328119#328119 ________________________________ Message 17 ____________________________________ Time: 06:48:55 PM PST US From: Lynn Matteson Subject: Re: Kitfox-List: Re: Composites and mold work I bought the publication "Moldless Composite Sandwich Aircraft Construction" by the Rutan Aircraft Factory, and in it there is an exercise where you make three different pads of fiberglass, each one to measure 8" x 8". You make one too wet, one too dry and one "just right", by squeegeeing with many light strokes. After curing, each is cut to a size of 7" x 7", then weighed and compared. They say the correct weight should be 2.25 ounces. If the heavy one weighs 2.55 ounces, it will add 35 pounds to the finished VariEze, if this heavy construction is used throughout the building of the plane. I'm sure we can guess what happens if the light method is followed. When I recently made spats for my skis, I did the 8" x 8" pads, but I was more interested in how thick and how strong 2 plies, versus 3 plies, versus 4 plies would be. I settled on the 2 plies for my project....the 4 plies (of E-glass) would have been almost strong enough to make the ski bottoms from....it was stiff! I've never given any thought to the pre-pregs...how do you "kick off" the curing activity? There must be something added to the pre-pregged cloths, isn't there? That technology just seems a bit out of my league. : ) I used bi-directional E-glass cloth for my spats, because I was limited by the amount of angle that I could get by using material that was only 50 inches wide. My method was probably not going to meet aircraft-building standards, but I feel that it was good enough for the task of keeping snow off my skis. Lynn Matteson Kitfox IV Speedster, taildragger Jabiru 2200, #2062 Sensenich 62"x 55.5 Wood (winter) until the Prince prop arrives Electroair direct-fire ignition system Rotec TBI-40 injection Status: flying...1080+ hrs (since 3-27-2006) On Jan 23, 2011, at 6:29 PM, Noel Loveys wrote: > > You're right Lynn. However not all resins will cure at room > temperature. > The same resins in Pre-preg are available for wet layup. They will > require > heat even if applied locally to cure properly. When filling cloth > with > resin for the greatest strength and least weight there is a ratio > of cloth > to resin by weight which should not be exceeded. Because the > stiffness is > caused by the resin and the strength is actually in the cloth too > much resin > or too little resin makes for a weaker part. > > The process I use is to fill my cloth with resin. I generally weigh > the > cloth and the mixed resins. Then I sandwich the cloth in clear > plastic and > squeegee out any excess resin. (usually not very much) Then I can > put the > cloth "sandwich" rolled up in a refrigerator while making more > "sandwiches". > When I have all the cloth I think I'll need in the sandwich from > (plastic on > both sides) I then start my lay up... rolling each layer of cloth > into the > previous layer. Doing it that way more or less insures me of two > things... > an efficient amount of resin in the final product and I can easily > see voids > as I do the layup and roll them out. > > When we trained in composites we generally used uni-directional > cloth but we > also followed a bagging schedule which laid out the direction the > warp of > each layer ran. Some bagging schedules had many layers of cloth. > Following > the schedule religiously ensured good strength in all directions. > You would > be amazed at the strength of a piece of composite glass or graphite > two > inches long and 1/8 in thick(in both directions) > > There is a problem with vacuum bagged composites which comes up > from time to > time. That is it is porous. A small insignificant nick in the > finish of say > a 777 cowl can be very dangerous as rain water can seep into the > material > through a scratch. At altitude the water freezes and the cowl can be > internally forced apart by the expansion of the freezing water. A > slight > rub by a forklift brushing an aluminium cowl may not be of any > concern. The > same damage to a composite will ground the aircraft until the cowl is > replaced.... bring MONEY! > > The crown who were specializing in composite repair (not me) used > to make > forms to mould on. Those Forms (plugs) were made of straw wet with > some > kind of plaster for the rough shape then finished with plaster of > paris > which can be sanded to final shape and then waxed. > > Noel ________________________________ Message 18 ____________________________________ Time: 08:22:10 PM PST US Subject: Kitfox-List: 582 throttle cable From: "369PL" Just had my 582 rebuilt. Was in the process of doing the Rotax breakin procedure. Pushed throttle in for the first high rpm blast. Engine rpm dropped out. Thought it was a major problem. Turned out cable broke at the mixer. Has anybody else had this to happen? :( Read this topic online here: http://forums.matronics.com/viewtopic.php?p=328162#328162 ________________________________ Message 19 ____________________________________ Time: 09:04:40 PM PST US From: "Lowell Fitt" Subject: Re: Kitfox-List: Re: Kitfox-List Digest: 8 Msgs - 01/22/11 I am enjoying this discussion. It is informative and nice to see that there are those that like trying new things and willing to share experiences. The Lancair I spend a year and a half on was was pretty much built from vacuum bagged skins - everything carbon fiber, except rudder. Vacuum bagging was pretty obvious as the outer skin was slick and the inner was covered by peel-ply. sandwiched in were foam stiffiners. We did wet lay-ups, but it was mostly as doublers under Hysol bonded joggle joints or fitting bulkheads. We used the squeegee between plastic mostly. I also made gap seal cuffs in the horizontal and vertical tails of my current Model IV project. I vacuum bagged them for the same reason the Lancair folks did theirs - weight reduction. Also they had complex shapes and since much of it would be on a visible surface, it was the only way to get a really nice adaptation and surface. I figure that the cuffs plus the electric trim tabs in both rudder and elevator added about six pounds. At the eleven foot arm that far back, I think the vacuum bagging saved me significant weight. I mention this because there are good reasons for vacuum bagging on our little low tech airplanes. If you are making wing strut fairings which will be right under the CG, probably not an issue except for empty weight considerations, but I didn't want extra weight way back there. One further thought. I usually only put the bagging film on one side. I would use a sheet of aluminum or one of the white laminated shelve boards available from Lowes or Home Depot as the sealing tape stuck fine to that and it didn't leak. I also found that by pulling the bagging film off with a quick jerk, it would often separate from the tape and the tape could be used again. for the next part. Being that I was making the gap seal cuffs and all parts had basically the same outside dimension, the board and repeat use of the tape saved some money. A couple of notes regarding recent posts. My vacuum pump - for vacuum investing for lost wax casting - was pricey even in its day. Along with the auto air conditioner compressor, I once used a compressor out of an old refrigerator, plumbed backward, they can suck a real vacuum. And the refrigerator compressor has a motor attached. Also, I always mix in less than two ounce mixes and use an electronic gram scale for proportioning. Place the cup on the scale and zero out the cup weight and go from there. I use a 4:1 mix so 40 grams resin equals a 50 gram mix. Lowell -------------------------------------------------- From: "great bear" Sent: Sunday, January 23, 2011 2:51 AM Subject: Kitfox-List: Re: Kitfox-List Digest: 8 Msgs - 01/22/11 > > A followup on vacuum bagging and heating fiberglass for curing...There is > a lot > of structural work in building a Glasair...I never vacuum bagged any > part...everything was hand layed two or three layers at a time...as long > as the > room temps was close to 60- 70 degrees the glass would cure to sandable > over > night so there was no need to heat anything if ambient was close to that > range....most builders (including myself) would wait for a cool day ( > 45-50) to > layup big stuff like the wing spars and major assemblies so that the > working > time and pot life would be long enough to make adjustments, but keep in > mind the > cure time would be days for those parts under those conditions but the > bond > would be just as strong..and heat the room...not the parts if you > must...it > seems like there is many approaches to this subject but I definitely agree > that > vacuum bagging parts is a waste of material and time for the projects we > are > doing...if you were building one of rutans space planes or 50 foot > windmill > props I could see a reason....but fuel tanks and speedcuffs, > cowling..little > fairings....not worth the time and extra material..west epoxy is almost > clear so > it works great if your going to leave parts natural..best stuff I have > used so > far...I didnt start out with that system but once I found out about it I > wouldnt > recommend anything else so far.......Gary ..,,,,,KF5 Outback.0-200 at > 80%....Glasair 1TD flying... and Cessna 170A (My daily driver) > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kitfox-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kitfox-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kitfox-list Browse Digests http://www.matronics.com/digest/kitfox-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.