Peel Ply
10-28-2009, 03:01 PM
#26
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RE: Peel Ply
What sort of finish does the peel ply leave? I assume that if you are looking for the glass smooth surface, you simply use a release film/mylar right on top of the wetted cloth?
The peel ply is a treated rayon with a very fine weave. That will be the finish on the wing surface. One coat of good quality primer is enough to fill the weave.
Ed S
10-28-2009, 03:50 PM
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RE: Peel Ply
What Ed said,
Often the LE is glass or Kevlar covered first. A little sanding maybe required to smooth out where the Mylar ends. There are tricks to keep the LE covering in place. One popular trick from Mark Drela is 3M77 spray adhesive and an ironing, after it has been in place long enough to be dry, to make it tack well to the foam LE. The mylars are trimmed to be just shy of the LE. Some even scrape or sand the mylar edges(on the top side to keep the inside smooth) to get it to wrap and come closer to the LE. The guys that are good at this wax the contacting surface of the Mylar a few times and apply the finish paint to the waxed surface. The paint bonds to the epoxy and and becomes he final finish. A close look at some of these finished parts show no paint or color on the LE. It comes darn close though.
post #75 in RCGroups Sailplane/thermal forum
"Another Supra Build - the slow way" addresses this issue by builders with oodles of experience.
If you want to try composite building reading that build log isn't a bad learning experience IMHO.
Often the LE is glass or Kevlar covered first. A little sanding maybe required to smooth out where the Mylar ends. There are tricks to keep the LE covering in place. One popular trick from Mark Drela is 3M77 spray adhesive and an ironing, after it has been in place long enough to be dry, to make it tack well to the foam LE. The mylars are trimmed to be just shy of the LE. Some even scrape or sand the mylar edges(on the top side to keep the inside smooth) to get it to wrap and come closer to the LE. The guys that are good at this wax the contacting surface of the Mylar a few times and apply the finish paint to the waxed surface. The paint bonds to the epoxy and and becomes he final finish. A close look at some of these finished parts show no paint or color on the LE. It comes darn close though.
post #75 in RCGroups Sailplane/thermal forum
"Another Supra Build - the slow way" addresses this issue by builders with oodles of experience.
If you want to try composite building reading that build log isn't a bad learning experience IMHO.
11-02-2009, 08:30 AM
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RE: Peel Ply
The purpose of the peel ply is NOT to absorb the resin. The breather cloth absorbs the resin. The peel ply allows the resin to pass through it into the breather cloth. The peel ply is purely a release medium between the glassed surface and the cloth. If it was not used the cloth would be stuck to the wing.
Other Nylon/Silk/Rayon materials might work. However if they do not there will be a whole mess stuck to the wing. I have never experienced this problem because I always use the CORRECT materials.
Ed s
Other Nylon/Silk/Rayon materials might work. However if they do not there will be a whole mess stuck to the wing. I have never experienced this problem because I always use the CORRECT materials.
Ed s
11-02-2009, 08:40 AM
#32
RE: Peel Ply
that's what i was thinking Ed. i walked into a cloth store and asked for dress liner. at a dollar or 2 a yard i bought 10,15 or 20 yds, i don't remember. i shouldn't have to go back for yrs and it works perfectly.
