GPW wrote:“ that it will actually reduce the strength of TB2 “ .... logical but not quite applicable , only because even thinned TB2 will make a stronger bond than the Foam ... The foam always will fail first , not the glue ... Try wetting the fiberglass cloth with plain water before applying the glue , A common spray bottle will work ...
The structural strength of skin is required in my case of roof upper part not so much adhesion of the foam, since there is no other structural element but the skin. I think I'll need all strength that TB2 can provide in the laminate.