It's been said before, but it's worth saying again. Don't use microballoons (or any filler meant for fairing) as a structural filler (fillets). The same property that make it easy to sand when fairing makes a weak joint when used for filleting.

Ross

> Hi John;

> I had never considered microballoons for a finish coat. I can assure you
> that after completely sanding the hull three (yes, 3) times now, straight
> epoxy can be faired with no problem. I kinda feel this was necessary on my
> first build, to get a feel for what condition the hull was in between fill
> coats. If you've never done it before, like me, it is hard to tell by
> eyeballing. In the future, one sanding at the end of the fill coats will
> do it, now that I know how much epoxy is needed and where the trouble
> spots lie.

> I have some glass microballoons, and from my R/C days seem to recall they
> were fairly clear, but that technique might be reserved for painted hulls.
> Perhaps another poster knows for sure.

> Best Regards, Spidey