SB #7 refers to structural tests the manufacturer was to perform to ascertain whether the strength of epoxy using microballoons would be comparable to that using cotton flox. I can't find any further reference to these tests and wonder whether they showed acceptable strength for wing applications using microballoon thickened epoxy.

questions...
1. Is there a visual way to tell if the epoxy used in wing construction was thickened with flox or microballoons?
2. Is there any reference to the test results?
3. Is a wing made with microballon thickened epoxy acceptable?

thanks!
jon