---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Thu 12/13/07: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:37 AM - Re: What should a fiberglass cowling weigh? (Phillips, Jack) 2. 08:47 AM - Re: What should a fiberglass cowling weigh? (Gordon Bowen) 3. 09:21 AM - Re: What should a fiberglass cowling weigh? (Brian Kraut) 4. 11:23 AM - What should a fiberglass cowling weigh? (Steve Glass) 5. 12:04 PM - Re: What should a fiberglass cowling weigh? (KMHeide, BA, CPO, FAAOP) 6. 12:43 PM - Re: What should a fiberglass cowling weigh? (Gordon Bowen) 7. 12:59 PM - Re: What should a fiberglass cowling weigh? (Gene & Tammy) 8. 02:22 PM - Re: build vid (jimd) 9. 02:39 PM - building log--keeping it simple (Cuy, Michael D. (GRC-RXD0)[ASRC]) 10. 02:57 PM - Re: What should a fiberglass cowling weigh? (jimd) 11. 04:45 PM - Jack Textor's Control Horns () ________________________________ Message 1 _____________________________________ Time: 07:37:58 AM PST US Subject: RE: Pietenpol-List: What should a fiberglass cowling weigh? From: "Phillips, Jack" Ben, like most things the answer is - "it depends". It depends on how much your airplane weighs, on how short your home field is, how much YOU weigh, and a number of other factors. As I've indicated before on this list, I consider my Pietenpol to be too heavy at 745 lbs empty. Have I done anything about it? Not a thing, other than to add 5 lbs to my own useless load over Thanksgiving. Most Piets are tail heavy and having an additional 7 ot 8 pounds on the nose will mean you won't have to shift your wing quite as far aft as you would otherwise. Watch the weight in other areas and you should be fine. Areas where you can compensate include using lightweight fabric on your fuselage and tail surfaces. In addition to the fabric itself being lighter, the lightweight fabric doesn't require as many coats of dope or polyspray to fill the weave, and the weight of the finish coats can easily exceed the weight of the fabric. When I recover mine (hopefully not for another 25 years) that is what I will do, and I sure won't be using polyurethane paint. That stuff is incredibly heavy. I'll bet I'm carrying around at least 40 lbs of paint on my Piet. Good luck, Jack Phillips NX899JP Raleigh, NC -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Ben Charvet Sent: Wednesday, December 12, 2007 7:30 PM Subject: Pietenpol-List: What should a fiberglass cowling weigh? Well, after 3 months of on again, off again work I've successfully removed my fiberglass cowling from the male plug mold that I made. I laminated it up from 4 layers of fiberglass cloth using polyester resin, as described in the Tony Bingelis books, under the chapter "How to make a Fiberglass cowling, if you must". Now I know what ole Tony was talking about. It actually looks pretty nice and has some nice compound curves that would be impossible (for me) to duplicate in aluminum. What concerns me is it weighs 10 pounds. I have a J-3 aluminum cowl on my Baby Ace, and it only weighs about 2 pounds. The cub cowl is about 4 inches too short to fit my Piet, so that wasn't an option. I'll try to post a few pictures in the next few days, but what do you guys think about the weight? Ben Charvet Mims, Fl _________________________________________________ or otherwise private information. If you have received it in error, please notify the sender Dansk - Deutsch - Espanol - Francais - Italiano - Japanese - Nederlands - Norsk - Portuguese ________________________________ Message 2 _____________________________________ Time: 08:47:37 AM PST US From: "Gordon Bowen" Subject: Re: Pietenpol-List: What should a fiberglass cowling weigh? Ben, Jack Phillips answer is probably right on the money. "it depends". Heck, because of my weight I had to move the entire engine 4" forward to get a good CG., a big heavy cowling would probably do me good. But back to lightweight correctly made composite parts. You can make a composite cowling just as light as the AL on the cubbie BUT, lots of techniques and tricks involved. A) People who don't do a lot of composite parts always ALWAYS use too much resin. It makes the part nice and smooth looking, but makes it heavy. The resin doesn't make the part strong, the fabric does. I ran the composites workshop at Oshkosh for several years and the one key observation I came away with after watching 100's of novice potential composite homebuilders try their skills on trial composite parts.....homebuilders always want to use too much resin on their parts. One part by weight fabric to one part by weight mixed resin is a good laminate. 40% resin is better, but hard to do without vacuum bagging. B) Resin choice... Polyester resins tend to go on heavier than two part epoxies, making a resin rich heavy part. Polyesters resins belong on things like shower stalls not on airplanes. C) Carbon fabrics are lighter than fiberglass. Kevlar is lighter than carbon, but harder to work with. But choice of weave of fiberglass is important to get smooth finish without too much resin, open box weaves suck up a lot of resin. Try a tight closed satin weave like 7781, 3783 glass or 613 style in carbon. D) If you can, get a look at the first 10 pages of the instructions for a Longeze or Cozy. See if anyone in your EAA Chapter will let you read the intro by Rutan or Nat Puffer on how to get a lightweight composite laminate. Then try again with carbon weave 613 and epoxy to make your part on the plug, you'll be much happier with the result. Gordon ----- Original Message ----- From: "Ben Charvet" Sent: Wednesday, December 12, 2007 3:29 PM Subject: Pietenpol-List: What should a fiberglass cowling weigh? > > Well, after 3 months of on again, off again work I've successfully removed > my fiberglass cowling from the male plug mold that I made. I laminated it > up from 4 layers of fiberglass cloth using polyester resin, as described > in the Tony Bingelis books, under the chapter "How to make a Fiberglass > cowling, if you must". Now I know what ole Tony was talking about. It > actually looks pretty nice and has some nice compound curves that would be > impossible (for me) to duplicate in aluminum. What concerns me is it > weighs 10 pounds. I have a J-3 aluminum cowl on my Baby Ace, and it only > weighs about 2 pounds. The cub cowl is about 4 inches too short to fit my > Piet, so that wasn't an option. I'll try to post a few pictures in the > next few days, but what do you guys think about the weight? > > Ben Charvet > Mims, Fl > > > ________________________________ Message 3 _____________________________________ Time: 09:21:57 AM PST US From: "Brian Kraut" Subject: RE: Pietenpol-List: What should a fiberglass cowling weigh? Sounds a bit heavy. Depending on how you did it you may have a lot of resin on the inside or outside or both. You might be able to sand a good bit of it away before you get to the glass. Then again, you might have a lot of resin inside the glass layers and might not be able to sand away much. Brian Kraut Engineering Alternatives, Inc. www.engalt.com -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com]On Behalf Of Ben Charvet Sent: Wednesday, December 12, 2007 7:30 PM Subject: Pietenpol-List: What should a fiberglass cowling weigh? Well, after 3 months of on again, off again work I've successfully removed my fiberglass cowling from the male plug mold that I made. I laminated it up from 4 layers of fiberglass cloth using polyester resin, as described in the Tony Bingelis books, under the chapter "How to make a Fiberglass cowling, if you must". Now I know what ole Tony was talking about. It actually looks pretty nice and has some nice compound curves that would be impossible (for me) to duplicate in aluminum. What concerns me is it weighs 10 pounds. I have a J-3 aluminum cowl on my Baby Ace, and it only weighs about 2 pounds. The cub cowl is about 4 inches too short to fit my Piet, so that wasn't an option. I'll try to post a few pictures in the next few days, but what do you guys think about the weight? Ben Charvet Mims, Fl ________________________________ Message 4 _____________________________________ Time: 11:23:55 AM PST US From: Steve Glass Subject: Pietenpol-List: What should a fiberglass cowling weigh? Hi It seems to me it would make sense to wax up the existing cowl and use that as a plug to make a new female mold. Then different cowlings could be pro duced Knowing the surface area a layed up weight can be calculated. In the boat business we would use glass "cloth ranging in weights from 1 oz to 32 oz de pending on the application. I would think a 3/4 oz mat and 18 oz roving wi th some local stiffners or some balsa core would be a good starting point. A lot of work for a few lbs of weight that will probably be in the right pl ace anyways. Steve snowed in in Maine with more coming this weekend. ________________________________ Message 5 _____________________________________ Time: 12:04:33 PM PST US From: "KMHeide, BA, CPO, FAAOP" Subject: RE: Pietenpol-List: What should a fiberglass cowling weigh? Ben, If you are truly wanting an opinion about the weight of your cowling compared to man other fiberglass cowlings....I have your answer! The company, Fiberglass Specialties, Inc. Attn: Bob Snell located in Watertown, South Dakota is a manufacturer of fiberglass cowlings for most of the aviation industry! In his shop he has done cowlings for most of the airplanes you can mention. He is a great resource for information and he can also take special orders, one offs and many other things you may need. As for pricing...extremely fair and very reasonable. He is in business to have customers....not chase them away! I can assure you he can tell you if your cowling is within weight limits compared to the many he has done. Here is his phone number 605-886-9206 and please use my name and the pietenpol plane. He will remember. I stumbled upon him while in town killing time before a meeting and was wowed at his operation and the many cowling he does for aircraft manufacturers. Finally.... no information should be given without an exchange for ride in your pietenpol....deal? tee-hee-hee Ken H "Phillips, Jack" wrote: Ben, like most things the answer is - "it depends". It depends on how much your airplane weighs, on how short your home field is, how much YOU weigh, and a number of other factors. As I've indicated before on this list, I consider my Pietenpol to be too heavy at 745 lbs empty. Have I done anything about it? Not a thing, other than to add 5 lbs to my own useless load over Thanksgiving. Most Piets are tail heavy and having an additional 7 ot 8 pounds on the nose will mean you won't have to shift your wing quite as far aft as you would otherwise. Watch the weight in other areas and you should be fine. Areas where you can compensate include using lightweight fabric on your fuselage and tail surfaces. In addition to the fabric itself being lighter, the lightweight fabric doesn't require as many coats of dope or polyspray to fill the weave, and the weight of the finish coats can easily exceed the weight of the fabric. When I recover mine (hopefully not for another 25 years) that is what I will do, and I sure won't be using polyurethane paint. That stuff is incredibly heavy. I'll bet I'm carrying around at least 40 lbs of paint on my Piet. Good luck, Jack Phillips NX899JP Raleigh, NC -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Ben Charvet Sent: Wednesday, December 12, 2007 7:30 PM Subject: Pietenpol-List: What should a fiberglass cowling weigh? Well, after 3 months of on again, off again work I've successfully removed my fiberglass cowling from the male plug mold that I made. I laminated it up from 4 layers of fiberglass cloth using polyester resin, as described in the Tony Bingelis books, under the chapter "How to make a Fiberglass cowling, if you must". Now I know what ole Tony was talking about. It actually looks pretty nice and has some nice compound curves that would be impossible (for me) to duplicate in aluminum. What concerns me is it weighs 10 pounds. I have a J-3 aluminum cowl on my Baby Ace, and it only weighs about 2 pounds. The cub cowl is about 4 inches too short to fit my Piet, so that wasn't an option. I'll try to post a few pictures in the next few days, but what do you guys think about the weight? Ben Charvet Mims, Fl _________________________________________________ or otherwise private information. If you have received it in error, please notify the sender Dansk - Deutsch - Espanol - Francais - Italiano - Japanese - Nederlands - Norsk - Portuguese Kenneth M. Heide, BA, CPO, FAAOP --------------------------------- Never miss a thing. Make Yahoo your homepage. ________________________________ Message 6 _____________________________________ Time: 12:43:48 PM PST US From: "Gordon Bowen" Subject: Re: Pietenpol-List: What should a fiberglass cowling weigh? Steve, Think using roving will absolutely make a very heavy composite part, never used in composite homebuilts for skins. Like the idea of using the current part as a female mold. Two plies of 6 oz. carbon with "hat sections" using 3 lb/cubic ft foam core where stiffeners are needed, does the trick. Carbon is stiff anyway, stiffen the edges where the two or three parts come apart is all that is needed on a 200 mph Cozy or Longeze. A Piete at 70 mph wouldn't need that much. Next time anyone sees a Longeze or better yet a Glassair on the flightline, give the cowling a good looking over. The skins are very thin with stiffener around the air outlet and inlet lips meet fuselage and along where the side piano hinge is laminated in. (pull the hinge pins and a couple screws to remove the cowl) Gordon ----- Original Message ----- From: Steve Glass To: pietenpol-list@matronics.com Sent: Thursday, December 13, 2007 10:23 AM Subject: Pietenpol-List: What should a fiberglass cowling weigh? Hi It seems to me it would make sense to wax up the existing cowl and use that as a plug to make a new female mold. Then different cowlings could be produced Knowing the surface area a layed up weight can be calculated. In the boat business we would use glass "cloth ranging in weights from 1 oz to 32 oz depending on the application. I would think a 3/4 oz mat and 18 oz roving with some local stiffners or some balsa core would be a good starting point. A lot of work for a few lbs of weight that will probably be in the right place anyways. Steve snowed in in Maine with more coming this weekend. ________________________________ Message 7 _____________________________________ Time: 12:59:38 PM PST US From: "Gene & Tammy" Subject: Re: Pietenpol-List: What should a fiberglass cowling weigh? Ben, Before you become too concerned about your cowling weight, do a W & B to see if you need the additional weight up front. A lot of Piets are tail heavy and a heavy cowling may be a blessing. Just a thought Gene ________________________________ Message 8 _____________________________________ Time: 02:22:32 PM PST US Subject: Pietenpol-List: Re: build vid From: "jimd" Idea of having build video's is great. Not very practical. Start to finish you might have 1000-2000 hrs of video, maybe a bit more or less. However.. no one I know would watch 1000 hrs of video. To edit video and make something useful out of it you typically make at least three passes watching and editing each part, and most the material ends up being cut. The idea of not having to do anything to capture the video is questionable, as you would need a camera man keeping the right thing in the picture, zooming in when needed, etc. What you could do is to map out your activities ahead of time, and figure out what you want to capture, then capture it, adding all those things that happen that you didn't count on. Time wise that would amount to editing before you capture, and would reduce your 1000+ hrs of video to a small fraction of that (100 hrs-200hrs maybe), would force you to think it out ahead of time to. I am building my first plane and find it challenging to keep up a build log, get digital pictures, track expenses and still have enough time to get work done with all the zillion things that come up. So my experience is not from building planes, its from my work. At work I have to document how I built computer monitoring systems that are big and complex and take as long as a year to build. For that I have found it works far better to break project into key pieces, figure out what someone would need to know to accomplish the key things, then document those. It takes me about a week of total time to pull together a systems document from all my notes I do during that year of building a system. (Course its software so I can take all my pictures at the end, for construction you would need to do it during the build.) With Still pics I think this approach would work pretty good. Video is much harder to do well, setting up a camera and going in front of it to do stuff will suprise you, you will probably not be happy with one take, but will want to redo and redo the "scenes". Go for it if you can, but it would distract me from building to much to do it the way your thinking of doing it. Over the years I have written about twenty-five aprox 300 page books of documentation for my work, and its been manageable. Only one project did I use video's, and it took about 5-6 times as long and I hated the sound of my voice on them. Just some things to think about. Good luck, Jim Read this topic online here: http://forums.matronics.com/viewtopic.php?p=152018#152018 ________________________________ Message 9 _____________________________________ Time: 02:39:02 PM PST US Subject: Pietenpol-List: building log--keeping it simple From: "Cuy, Michael D. (GRC-RXD0)[ASRC]" My building log tools consisted of three things: 1) yellow sticky note pads 2) a couple accordion manila file folders 3) camera If you have a camera with a date stamp you can skip item 1. I would order what I needed from Wicks, ACS, or Dillsburg Aero or even the hardware store and file those invoices under several different folders like: Airframe, Engine & prop, Covering, Instruments. I would take pics once in a while of my progress using the yellow sticky note on the parts or assembly to date the event. When my inspection came I had the folders with all of my purchases spread out neatly and my photos pasted on some white posterboards in chronological order. Simple as that. Nothing elaborate is necessary at all and if it it, get a different DAR or inspector or read the regs and fight them at the nearest MIDO office. Mike C. ________________________________ Message 10 ____________________________________ Time: 02:57:13 PM PST US Subject: Pietenpol-List: Re: What should a fiberglass cowling weigh? From: "jimd" Have similar concern. My cowling has a big oval opening on it that needs some kind of cover over it. (Opening is about two foot long and a foot wide.) My engine is a 125hp ENMA Tigre with a couple giant magnetos on the top of the back end of the engine. First thought was lay something about as thick as the clearance I need over the mags and engine, then make a dam around the opening and use the shape as a male mold to make the big hood bump thing out of fiberglass. To be able to access the mags without removing the whole cowling the bump would have to sit on top of the aluminum cowling. Then there would need to be some kind of fasteners, that would attach the bump to the cowling, and a means of dealing with fiberglass not expanding contracting at same rate as aluminum. Also the design is vintage 1930's, but a glass bump is more 1970's. So, I started looking in to what it would take to make a bump out of aluminum, and watched some you tube video's on aluminum forming. Turns out compound curves can be made with a good deal of effort, people that are in to that kind of thing can make reproduction Ryan radial cowlings from sheet aluminum, complete with the bumps for each cylinder. I spent the last 2 days trying to take my aluminum leading edge for the center section of the wing and polish it out like a mirror. (Plan on having wood polyurethaned and natural looking, and the aluminum shiny, rather than covering it like everyone else does.) Its taken 3 times the work I thought it would and I am only half done. Will have about a week in getting the center section pretty by the time I am done. Should make my plane distinctive, but I can tell you now there are no Luscombes or Swifts in my future. My point being that aluminum is light, and can be made pretty, but it takes a lot of work to make something curvy and nice out of it. Flat pieces rivet together quick, and paint pretty easy, but its hard to get something that looks really nice without a lot of effort in the design or the construction or both. The factories tend to use a fiberglass nose bowl so they can have some compound curves, then make the bulk of the cowling out of fairly simple flat aluminum sheet. If you already sank the time in to making a mold and your cowling looks good, then move on to something else. When your plane is done you can always revisit it. How many hrs and $$ will it take to save how many pounds? Do you have big flat areas on your cowling that could be replaced with aluminum? Maybe your curvy part could serve as a nose bowl. I have been looking for a simple aluminum hood scoop design made up of all flat pieces or with very easy to do compound parts. So far no luck. But rather than dwell on it I am moving on. Jim Read this topic online here: http://forums.matronics.com/viewtopic.php?p=152030#152030 ________________________________ Message 11 ____________________________________ Time: 04:45:50 PM PST US From: Subject: Pietenpol-List: Jack Textor's Control Horns Jack, I was looking at the photos on your web page (www.textors.com) and noticed you have some good looking control horns. Would you please share with us how you formed the control horns. Chris Tracy Sacramento, Ca Website at http://www.WestCoastPiet.com ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message pietenpol-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Pietenpol-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/pietenpol-list Browse Digests http://www.matronics.com/digest/pietenpol-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.