Very, very little heat on the blank. If its too hot to touch, its too hot for the graphite. Doesn't take much heat to ruin a blank.... ask me how I know that one
Same with hot glue in the tip top. If I can't hold the tip top with my fingers when I heat it, to melt the glue, I consider it as too hot. But, that's just me and my experiences.
I avoid using any type of epoxy for gluing on tip tops. Epoxied tip top... good luck getting off if you ever need to.