Thanks, 'Spoke. I bought this (as well as the sanding sealer and clear) a while ago, before I realized that Target was the mfr. Good idea on the additives, silica is usually what's added to epoxy for filling or filleting. I may do some tests with it if I stick with this stuff.
My first thought was that I was pulling it out of the pores, so on the next application I thoroughly checked after squeegeeing, and it was perfectly flat and level. The filler sunk down into the pores after squeegeeing.
That's the thing, it doesn't set up quick at all (check my previous posts for some of the times that I waited before squeegeeing).