What is the main purpose of sealing the balsa skins before applying the laminating epoxy ? Is there a big advantage of doing so? The suggested sealants in this forum are 1) 50% Thinned Nitrate Dope, 2) Hair spray & 3) BalsaRite . Can I also use Shellac, Clear Laquer or any other wood sealants in cans or spray found in Walmart for sealing? Thanks