: Yes.
: Epoxy, milled glass fibers, and a bit of silica aka Cabosil will do
: the same job.
: It's more expensive, though.

The pre-mixed was the selling point. No fooling around making it up. Just throw in a bit of cream hardener and away ya go. Plus it dries hard in 15 minutes so no waiting around. My slow cure West System epoxy would be many hours before it dried hard.

I'm also dishing out around 170.00 for a gallon of resin/hardener, so I wanted to save that for glassing the hull/deck etc, rather than using it as a filler.

Sean