I have been using Phenolic Micro Balloons while taping the outer
chines, transom, and bow of my drift boat (especially to hold the tape
in place on the vertical surfaces) and as fairing compound to smooth
everything out after taping, because of the ease of sanding, but have
noticed tha glass micro balloons are about 1/2 as expensive as the
Phenolic balloons.

What are the strengths/weaknesses of using the glass balloons vs the
phenolic vs wood flour (which I used over the tape on the fillets of
the inner chines)?

I have also been considering using in the future a mixture of micro
fibers and some type of balloons w/ maybe a little fumed silica in the
future for my chine work, with micro balloons for fairing and
smoothing.

What are the relative merits of the different fillers above mentioned?

Thanks!