Tig weld vs J-B Weld...LOL

So I can't weld aluminum...But I've actually had some real good luck with J-B Weld on various things like on my old tractor where I plugged the threads on the old pitted thermostat housing... lol

I think there's also aluma-weld by matercool and even Devcon.

Am I taking a risk about using this on my water pump, to essentially "glue" on my -AN fitting? lol

I think it might just work and be okay...or not?