Over the years, I mixed everything imaginable. I would let the epoxy cure totally and sand it before further coats. Once epoxy cures (over a week) it becomes inert. I wouldn't go green to green stage with mixed brands. That's a gamble with a lot at stake.

I now settled in on RAKA. Price is right and I like the no-blush hardner and the viscosity is low for wet-outs. Everyone has their favorite and I think they all work fine.