O.K. you f/g experts, I need some help.

[abl1111]

A few questions:

As always, I humbly defer to your experiences, but there were two things mentioned that I thought were " no-no's":

o using micro balloons for water proof/underwater applications ( better to use cabosil ?)

o using mat with epoxy - I thought mat was not good w/ epoxy, and cloth was preferred ?

I just need this clarified for my info.... Thx.