Another one of my early designs. This was my second mold. When I built the first one (the little green jet looking one in the Old School post below), I made the mistake of using a wax that contained silicone. When I tried to PVA the plug, it just beaded up and would not make a solid layer. I went back to South Bay Plastics and talked to Herb Gerish about it. He told me to mist the PVA on in very light coats letting each one dry in between until I had a solid layer. This worked, except that it left a speckled texture all over the plug, which transferred into the surface of the mold. I didn't want to have that problem again, so when I built the mold for this plane, I decided that I was not going to use that crappy PVA and that I would just wax the heck out of the plug to keep it from sticking. What I didn't know is that polyester resin has wax in it. So when I layed up the mold, the plug got stuck so tight that I ended up ripping the plug in half trying to part the mold. Fortunately, I was able to salvage the mold well enough to make a sort of nasty looking part from it. The great thing about glass is that you can fix it really easily. A little Bondo and you're golden!
I don't use polyester anymore and maybe this would not be as much of a problem with epoxy, but I'm not going to try it to find out.
I was really looking forward to flying the plane in the last picture. Unfortunately, it met its demise on the maiden when I launched it at Fermin with the ailerons reversed.
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