One fairly lightweight way to seal balsa before latex is to: 1) use a very dilute (skimmed milk consistancy) solution of water and Titebond II to attach a silkspan skin to the wood; 2) when dry, use a brushable mixture of water and spackling compound to "paint" the structure; 3) when that is dry, sand almost all of it off, leaving just enough to fill the grain or weave of the silkspan; 4) prime (I use Kilz II, a latex primer) and paint. I will try to attach a picture of my project done that way. Good luck, Dzl
