Fiberglass over ply wing skins vs cloth

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Brian Clayton

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I need opinion/guidance. I am looking at a nesmith cougar project that needs recovering. The wings are ply covered with fabric over that. I know on the w10 tailwinds, fiberglass was used over the wing skin ply. I like the idea of glassing the wings, instead of fabric. But, other than some pictures, I dont know quite what is involved or if it is still a good idea. I didnt see any specific earlier posts on this subject when I looked. I am not married to anything yet, just looking for pros/cons and some guidance on the subject.
 

TFF

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Join the Tailwind Yahoo group. The short is you drape 1.75oz glass cloth on the surface, mix up West's Epoxy put on top and squeegee it out so there is enough through the fabric and into the top surface, let cure, trim, flip and repeat. Getting the fabric off, which if done right is ok, and sanding the surface down so the epoxy has good adhesion is going to be a chore.
 

Brian Clayton

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Cool acquisition.
we will see. I have not made my mind up yet. I am a bit long legged, and tailwinds/cougars are not the most friendly to tall people. I folded into this one....its unflyable tight for me as it is right now. This one does not have the clement mods, and part of what I am trying to decide is if I want to take that much apart. I think its a really good deal......IF I dont turn it into a major reconstruction project.
 

Brian Clayton

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Join the Tailwind Yahoo group. The short is you drape 1.75oz glass cloth on the surface, mix up West's Epoxy put on top and squeegee it out so there is enough through the fabric and into the top surface, let cure, trim, flip and repeat. Getting the fabric off, which if done right is ok, and sanding the surface down so the epoxy has good adhesion is going to be a chore.
They use epoxy like for wood? I assume you have to fill the weave with something and sand it smooth once you put on the cloth/epoxy?
 

Aircar

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Brian, the trick is to 'wipe' dry microballoons over the weave as soon as you have laid it up (while still wet ) the n micro will stick to the whole surface but remain in the hollows of the weave and let you get a smooth surface without cutting through the cloth and at much less effort --also take far less primer surfacer to get rid of the weave pattern and be lighter overall.
 

TFF

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There is debate on how to fill the weave on yahoo. One camp is one more coat of resin at min depth before auto primer and the other is start with the auto primer. some also have run a .75 oz cloth over the other for tight weave; too much work for me. Clement is a second coat of resin guy and seems to have the type nailed. What type of gear does it have? Cougar plans built gear is weak. Are you going to stretch it? What engine?
 

Pops

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I think TFF is correct, the Cougar gear is weaker than the Tailwind. I would go with the Tailwind if I had a choice of the two. The Cougar's sales cheaper for a reason. At one time many years ago, I thought about buying a Tailwind, taxied it out to the end of the runway and taxied it back. My feet were to big and even with a well in the floor for my heels, the toe of my shoes were rubbing the bottom of the fuel tank.
I have always liked the Tailwind. One sharp looking airplane. Dan
 

Brian Clayton

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Sounds like a lot of sanding, i.e. time. I wonder how time/expense compares to cloth? In my mind, it seems that composite covering is quite a bit more labor intensive and would cost quite a bit more. If I was building a w10 from scratch it would be fine, but I was really looking at this for a "fix and fly", not a long project. It has the cougar gear (bend at base of firewall/tapered steel legs). If I change engines, I have to build a new mount, so changing gear to tailwind would not be a issue. Pops, I feel your pain on big feet. I wear a 14, and it was close to the tank, less than a inch at my toes. It has a ea81 on it now, seller has a running 0-300/prop separate. My issue was my knees wedged against the bottom of the inst panel, easy fix there. There is a truss behind the seat, which the clement mod leans back. I dont think any of the clement mods stretch the cockpit area, but I may be wrong.
 

Toobuilder

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I did the West Systems epoxy over 1.75oz glass trick on the Hiperbipe. It was quite a bit of sand/prime/sand/prime after that. Came out spectacular though.

Also had an early W-8 Tailwind for a while and found I was just too tall. Even with the "Clement mods" it was going to be tight. If you get a Cougar, make sure you put the Tailwind gear on it.
 

Turd Ferguson

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A tailwind originally used conventional aircraft type fabric over the wood wing skins. Steve Wittman never used fiberglass. Jim Clement covered a set of wings with fiberglass cloth and resin, and many other builders followed suit. Be careful if you go back with aircraft fabric, needs a good surface.

Back in the foam/fiberglass era of plane building, the cloth weave was usually filled by skim coating featherfill over the entire structure. Since featherfill was a polyester product, over time it would sometimes work loose from the fiberglass base due to shrinkage. Fred Keller used to thin featherfill and spray it into the weave. His finish looked spectacular. I would use the lightest thing I could find, like epoxy and glass micro balloons.
 

autoreply

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Use fairly thick foil on top. If done right (wet out, squeezie, preferably vacuum-bag), you'll end up with a very light cover and an outer surface that's smooth as a piece of glass. Still have to sand the surface for a coat, but the other 90% of work (filling, sanding, filling etc) is no longer needed.
 

Brian Clayton

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Use fairly thick foil on top. If done right (wet out, squeezie, preferably vacuum-bag), you'll end up with a very light cover and an outer surface that's smooth as a piece of glass. Still have to sand the surface for a coat, but the other 90% of work (filling, sanding, filling etc) is no longer needed.
Thats what I was wondering, I just have never this sort of composite work. Just repairs and small non structural parts. Nothing this large. I guess in this application, the resin is for smoothing/ply protection and the fiberglass cloth is just to keep the resin/finish from cracking. Any links/ref material to see how its done? I hunted the old threads here, just didnt see anything that applied.
 

autoreply

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Thats what I was wondering, I just have never this sort of composite work. Just repairs and small non structural parts. Nothing this large. I guess in this application, the resin is for smoothing/ply protection and the fiberglass cloth is just to keep the resin/finish from cracking.
I presume so, yes. Why not throw the wood out and put carbon in anyways :roll:
Any links/ref material to see how its done? I hunted the old threads here, just didnt see anything that applied.
Wear protection!!!

Take very big pieces of foil and tension them on a table. Put glass on, wet out, put another layer of foil on top. Squeegee (sic?) out from the middle until it's throughly wet. Cut out pieces of the wet glass and the top layer of foil attached to eachother, cut of the extreme sides of the roll (wet) and drape them on the skin. Put it on right the first time and it'll stay a neat weave...
Bigger pieces gives less finishing but might handle awkward. A few experienced hands are invaluable. Put the next one on. Dependent on your preference, exactly next to the first part, or just overlapped. If you overlap, you can neatly cut the two foil/laminate layers together... but that requires some practise and is easy to get wrong. In doubt, put the lamina next to each other and bother with the 0.5" messy part in between later (put over a small strip of wet glass and sand back to the contour. A roll of glass is 50" anyway, so few sanding areas...

I figure you could do about 5-10 square meters/hour with two experienced guys that way.

Thicker foil gives great (laminar flow!) surfaces, but thin foil (.15mm or there about) might work just as well.
 

Brian Clayton

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I presume so, yes. Why not throw the wood out and put carbon in anyways :roll:

Wear protection!!!

Take very big pieces of foil and tension them on a table. Put glass on, wet out, put another layer of foil on top. Squeegee (sic?) out from the middle until it's throughly wet. Cut out pieces of the wet glass and the top layer of foil attached to eachother, cut of the extreme sides of the roll (wet) and drape them on the skin. Put it on right the first time and it'll stay a neat weave...
Bigger pieces gives less finishing but might handle awkward. A few experienced hands are invaluable. Put the next one on. Dependent on your preference, exactly next to the first part, or just overlapped. If you overlap, you can neatly cut the two foil/laminate layers together... but that requires some practise and is easy to get wrong. In doubt, put the lamina next to each other and bother with the 0.5" messy part in between later (put over a small strip of wet glass and sand back to the contour. A roll of glass is 50" anyway, so few sanding areas...

I figure you could do about 5-10 square meters/hour with two experienced guys that way.

Thicker foil gives great (laminar flow!) surfaces, but thin foil (.15mm or there about) might work just as well.
Is it easier to send the wings to you, or just buy you a plane ticket? :roll:
 

TFF

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In this use, I would not call it true composite as much as fabric covering with alternate materials. If it is doped or Stits and in good shape, I would go with it. I would even go back with it as it might be easier. Even though there is some increase in surface toughness, no one on the Tailwind Group claim any strengthening of the wing. If going light weight, you are not going to beat traditional materials. The W10 was on Wittman's mind but Clement asked him to put it on paper so he could build one. Clement has built 10 W10s now, I believe. Wittman sold the plans but it is as much Clement's baby as Wittman's. The Cougar is just a W8 knockoff without flaps and slight changes so it is "not a copy." Did it fly with the Sub? I started a thread on the yahoo group asking about putting a angle valve engine on a W10. I learned a bunch about how the plane evolved. I liked the idea of a Continental 6, but lycomings are going to end up lighter and are cheaper to rebuild with more HP per cid. Continental 0-300 cranks are getting expensive no new ones are made; a good one is worth a good chunk of cash. Depending on how fast you want to go 0-235,0-290,0-320 are the best bang.
 

Brian Clayton

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In this use, I would not call it true composite as much as fabric covering with alternate materials. If it is doped or Stits and in good shape, I would go with it. I would even go back with it as it might be easier. Even though there is some increase in surface toughness, no one on the Tailwind Group claim any strengthening of the wing. If going light weight, you are not going to beat traditional materials. The W10 was on Wittman's mind but Clement asked him to put it on paper so he could build one. Clement has built 10 W10s now, I believe. Wittman sold the plans but it is as much Clement's baby as Wittman's. The Cougar is just a W8 knockoff without flaps and slight changes so it is "not a copy." Did it fly with the Sub? I started a thread on the yahoo group asking about putting a angle valve engine on a W10. I learned a bunch about how the plane evolved. I liked the idea of a Continental 6, but lycomings are going to end up lighter and are cheaper to rebuild with more HP per cid. Continental 0-300 cranks are getting expensive no new ones are made; a good one is worth a good chunk of cash. Depending on how fast you want to go 0-235,0-290,0-320 are the best bang.
The wings have to be recovered because of "questionable fabric bonding" over the ply. The tail section has to be recovered because its not stitched, and some of it is just plain ugly looking. Didnt fly that I know of with the Sub (not in the logs anyway). The 0-300 engine is just a option for me, since it is a running complete engine at a good price. Should have enough time left for a lot of enjoyment. I am just looking at this project as a econo "fix and fly", not my dream plane or a rocket. Its cheap enough to patch up and have some fun with. I was just curious about the epoxy/glass covering as a viable option.
 

TFF

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Is the tail not stitched but covered the Maule way by gluing rib to rib? That is the standard way to do a TW. If it was just covered normal and not stitched, thats stupid. I think there was some debate on yahoo about that plane.
 
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