JB Weld is a form of epoxy and softens/melts with heat. Ditto Scott above. If you can get to it afterward, use a twisted wire wheel to clean up before brazing. Epoxy can also be cleaned, while in soft/liquid state, with acetone or white vinegar so maybe while still warm, after removal of the majority, wipe it down with one of those.
What's the last thing a red neck says, "Hey guys watch this."
What's the last thing a redneck hears, "Go ahead Bubba, you can do it."
Build plan: 65 Chevy one ton, 5.9L Cummins HO, NV5600 six speed, 2wd 1972-1987 IFS disk front, frame off restore/mod, custom dump/flat bed, Alcoa rims, Dana 70 3.73:1 duals drum rear, plush interior, Guards red with Marine Corps decals. Donor is retired 2002 Ram 2500, 194K miles.