This one isn't catastrophic, just disappointing. I mixed up a quantity of the red box stuff, add some of the fiberglass powder, and prepared to fill some slots in the forend of a sportered SMLE .303. When I got everything all set, I turned around and there was big, smoking head on my little cup of glass that looked like the foam on a rootbeer float, but was semisolid. I plucked out the blob, then poured the remainder into the stock gap and didn't have enough -- as that was solidifying too. What did I do wrong?

By the way, a YouTube clip of this would have been a hilarious installment in the "Home Gunsmithing Idiot" series ...

Bill,
Not sure what you did wrong, but I thought I would share my Acraglass goof.

I used too much material, not enough release agent. I had to cut the wooden stock off with a chisel.

Wasn't funny at the time, but my buddies got a great laugh. I laugh at it now & it gave me an excuse to buy a new stock.

You either mixed in too much hardener or didn't mix it thoroughly enough. And what you had was a very hot batch. FYI Depending on how hot you mixed it it won't be as strong as a slow cure batch would.
I had a buddy in the Fiberglas industry and they would mix up small batches for filler or small patches on various parts.
They would mix enough organic peroxide to make the resin boil and smoke.

How old was the box? More then two years??

I know when this stuff gets old it does some weird stuff

Kerry: Box shouldn't be that old. I must have used a bit too much hardener.