Sometimes you gotta laugh ... or cry.
As much fiberglassing as I've done over the years I thought I'd seen it all, epoxy and polyester. But today I saw epoxy eat up my styrofoam fuel tank plug. I switched to a faster hardener I hadn't used before and boy did it kick in - too fast and the heat shot up, melting the spray adhesive I used to assemble the blocks and then the foam as well. It basically all came apart and I ended up rolling it up in the plastic sheet I had on my workbench and taking it out to the driveway to cool off! Nice big mess.
Oh well, I'll make a new plug tomorrow. This time I'll lay in fewer layers at a time and allow it to flash off before adding more. Patience, patience. That should keep the heat down.