I have a Hohner GT3 headless guitar ( a knockoff of a Steinberger) that has
develops a slight bend as has a crack starting at the bend. I believe the
alloy is aluminum that is cast and then machined.

I fear that if I try to bend the part straight that the metal will crack and
break off.

I wonder if I could use the rod I saw advertised on TV that "welds" (seems
like soldering to me) using a gas torch.

Has anyone experience with this stuff? Please comment pro or con.