RE: 1/4 scale F9F Panther build
My airframe is in Joe's basement and I didn't want to fall behind so I worked some on my wing foam cores here at my house. We'd hot wire cut them earlier in the build. I laid out my sheeting in the foam beds from the core and trimmed and taped them using masking low tack tape (no CA gluing edges). It was pretty cheap at Hobo only 1.50 a roll. I lightly block sanded the ridges (leftovers from the wire cutting process)on the cores with 100 grit paper and removed the sanding dust. I then coat the sheeting with epoxy (US Composite) and scrape most of it off. I do like to leave the periphery a bit wet-just to keep the edges glued well. Here's a pic of the sheeting in the bed.