ORIGINAL: Newc
balsa wing skins provided the balsa skins are sealed with shellac or similar sealent
That's completely eliminating the reason for any bonding agent, especially epoxy, which is required to be absorbed by the balsa to be most effective.
Well, actually, no. The balsa doesn't need to 'absorb' any epoxy at all to be effective.
It is a common misconception that resin bonding systems must be 'absorbed' to develop their adhesive strength. As a matter of fact, the WEST System epoxy people, the Gougeon brothers, originally claimed they got the 'WEST' name from "Wood Epoxy Saturation Technique". They used that terminology extensively in their advertising. Go ask them about that now. They ABSOLUTLY will refuse to claim any such 'saturation' at all and they will vehemently try and distance themselves from their past claims... because as they became more knowledgeable about their own product, it became clear that no saturation, and hardly any absorption was taking place at all. Further, you can literally successfully bond two pieces of steel together, and there is no question of absorption in that application... but they are bonded nonetheless.
Tom