RE: Sealing and Painting Balsa
My favorites are as follows, based on weight, lightest first and assuming we are talking RC gas or glow models:
Japanese tissue/ Esaki and nitrate dope for bedding the tissue. Lite silkspan and nitrate are in the same league. Jap tissue is sealed in about 2-3 coats while lite silkspan in about 4. It's litest for gas and glow apps but not ding resistant. It's very thin
A close second is carbon veil and nitrate. This takes more effort since the veil is very sheer with lots of open areas that need filling, but is also very thin
Mediumsilkspan and nitrate dope for bedding
Japanese tissue or lite silkspanand Klass Kote clear epoxy paint. Epoxy paint is heavier than nitrate. So is urethane paint
Polyspan PET tissue and nitrate of KK epoxy paint. Polyspan is heavier than the paper tissues
I typically will bed with nitrate and make ready for primer in KK.I like KK primer; sands extremely thin
Then come the lite glass cloths, prefernce being the 0.6 ounce and epoxy paint. But it's heavier but no more ding resistant than the above
If you want ding resistance, you will need thickness and weight. Either epoxy finishing or laminating resin works well or polyester/vinylester finishing resin. BUT weight is a problem so if yours is not a weight issue, use that technique.