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Oct 02, 2012, 12:33 PM
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Lt599's Avatar

Glassing wings

This is a total newby question. I have been wanting to start glassing my models. I have read many, many forums and looked at alot of videos but what I cannot figure out is how do you finish the TE and LE on wings or control surfaces when you glass them? When you cover the top of the wing I see that you leave a small overhang of glass around the perimeter while it sets, then do the bottom the same way. How do you blend the top and bottom glass layers together around the edges??? I am obviously missing something here.
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Oct 02, 2012, 01:20 PM
Registered User
Lt599's Avatar
I read your reply on my other thread, I havent had a chance to try it yet. What got me to ask again is that after looking at several builds I never seen that part of the process? So I thought that there may be a way to blend the top and bottom glass at the edges, especially on thin wings, without having to lay glass around the edges first. I am getting ready to glass a foam core, balsa covered wing for an A10. I am going to use the method you describe for these, but I am trying to figure out what people are doing on these other builds where I do not see any edges being covered first? Thank you, I appreciate all the input
Oct 02, 2012, 02:03 PM
Just fly it!
wyowindworks's Avatar
If the glass is light you can often wrap it around larger leading edges and forgo the spray adhesive technique. If the TE is rather sharp you can just let the top and bottom layer come together at the TE.
Oct 02, 2012, 06:17 PM
608 km/h!
josh18's Avatar
How about adding a hardwood leading edge, then add your top and bottom cloth and sand the leading edge after. Any imperfections can be filled over the hardwood and you have a vere stong leading edge that doesn't risk getting too thin due to over sanding.
There are many ways to skin a cat, think whether you're after strength or light weight, both ways have their plusses and minusses.
Oct 02, 2012, 09:36 PM
Hope to get out of life alive
kenh3497's Avatar
I wind up with two layers on the LE of my flying surfaces. I use 3/4 oz cloth from Thayer. The "seam" left by having two layers is not an issue as it blends nicely. Just a little sanding is necessary. The trailing edge is just left to hang off and is removed after it cures by a light sanding with about 200 grit. I don't normally wrap the TE. There is enough epoxy to make the TE tough enough, at least in my opinion

Do the bottom first, just like you would with your favorite plastic wrap. I usually will do the hard parts like aileron ends, the joint at the tail parts and the "little" stuff first. Let it harden and then lay cloth up to the junction at as an example the vertical fin fuse joint. You get two layers there giving a tad extra strength.

There is much discussion about thinning epoxy. I do thin a tad with either acetone or denatured alcohol. It is said acetone is really the better thinning agent. I only thin the first coat as I only want to stick the cloth to the surface. I use a playing card or piece of balsa as a squeegee. If you see any shiny spots you have the epoxy to thick and you need to squeegee that out to a dry spot. A very light sanding with 400 dry to just knock the tops off the high spots. The second coat is the "filler" coat. this fills 95% of the weave. Then on to primer and paint.

The CAP in my avatar came out at 7 1/2 pounds. It is all glass and epoxy, and could have been lighter if I had not use yellow and red as colors as they do not cover well and I needed to use a lot of paint. It is clear coated with automotive urethane.

Oct 08, 2012, 11:10 PM
You can usually get the fibre round the leading edge ok but you need to cut the fibre so the weave is at 45 degrees.
Cutting it at 45 is good for nearly everything as you don't get loose fibres falling off the edge of the cloth and it goes round corners much more easily.
If you do cover a wing with epoxy and cloth then try to do both sides at the same time as the slight shrinkage can distort it, and that would really ruin your day.
Some fibreglass is very soft and other types are a bit stiff so try and get the soft one if you want it to go round the LE.
I use a credit card for squeezing the resin around the wing. You need to do it twice normally as there will be some dry areas. Don't try to get a shiny finish with too much resin, it should look matt. take off as much resin as you can with the credit card or similar.
Start in the middle and work outwards.

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