Yesterday, I used Bondo fiberglass filler (had an open can). I did not have any of the hardener that came with the can, so I used my normal epoxy resin hardener.

Today, the stuff is still soft.

What now?

What hardener is required for the Bondo fiberglass filler?

Should I mix a batch of resin with hardener and put a coat over the still soft Bondo?

Any way to get at least some (surface) hardness out of the already applied Bondo fiberglass filler?