I used vinyl spackeling to try and fill in a long crack in a sheeted wing and the water content cause the balsa to bubble up, so now what do I do ?
I have been using vinyl spackeling since I read Harry Higgly's book "There are no secrets" years ago and this is the first time to have a problem I expect because of the thinness of the sheeting and the large area applied to. BTW it did not fix the crack it just can through the spackle :
I should have known better cracks need either to be pulled together and bonded or filled with something flexible.

thanks
Jay