"eddy long" wrote
I'm doing a patch job to the underside of a fibreglass driftboat with
fibreglass matt and roving material (weave).

What is applied first after the area is wetted down woth expoxy resin -
the
matt or the weave?

I don't know the first thing about boats and I'm constantly proving it, but
I'd guess that you probably want to use your mat, it being the weaker of the
two, as sort of a filler material and the woven roving as the outer
structural stuff.