Tig weld vs J-B Weld...LOL

I’m a welder and Part of me thinks with the right epoxy, it would be fine. We use a lot of epoxy on structural anchors into concrete and the strength is amazing.
As for the 50$, I used to do a lot of freebies, a long time friend got used to it and seemed to think I was like on call or something. At one point I had to charge him 75$ to make some used 3” 67-69 camaro exhaust fit his 76 nova. When I called him and told him cars done come get it, keys are in it, it’s 75$ I won’t be home.
He said ok... wait what??? 75$??? Yeah,that’s right 75$. a refill on the tank, a roll of wire, and my electricity. Do you want me to get into the cost of the machine, and my time?
He said no, I was surprised that’s all you wanted... 75$ is a good deal...the favors didn’t stop but they sure slowed down. And there were times he would
Throw me 20$ after that.