Iv'e used the old K&B Superpoxy Polyester resin for years. I did these models, the Cessna is all Balsa TF Kit. and the F-18 is an old DCU f-18 kit, Balsa wings and stab with polyester. They were built in the early 90's. Pix taken today.
I always used 1 layer of 2 oz cloth. so it was less likely to dent. Also with poly, you can do 2 or 3 coats in a single day. Because it drys in 45 minutes sandable. I have an Oven
large enough to get an entire plane in.