Mixing Epoxy and Polyester in a cowl?
I made my first cowl using West Systems 105, and while it came out pretty good for my first one, it seems a bit too flexible. I was wondering if I used Epoxy as the gel coat, and for the glass layer use Poly resin to stiffen it? My friend made a cowl for his Cessna out of poly and it is much stiffer than the Epoxy is, but seems like it would be more likely to crack. I would like it a bit stiffer than it is, but more flexible than the plain poly. I used .5 oz cloth followed by 1 oz for the layers, and it weighs in exactly the same as the plastic cowl I modeled it from, though once the vents and the hole for the prop are removed, it will be lighter since that is where most of the weight is in the epoxy.
So can Poly be layered over Epoxy and bond, or will it separate after a while? I have 2 quarts of poly that needs to be used up, so looking for projects for it. Have 8 B-17 cowls to make next, and getting some practice in on the Chipmunk mold I made.
On the flip side, could it be done this way to make the mold?