I keep a tube of JB Weld in my toolbag in the trunk. Mine looks fine but if I was on a long trip and noticed pink stuff or it blew while I was driving my plan would be to try to plug it, fill it, and then look for a replacement radiator as soon as possible.
I wouldn't trust a JB Weld repair except as a stopgap, but if you wanted to use it to try and reinforce that area before it cracks it's probably no worse than doing nothing. About the only downside is that if the hairline crack is starting to form you won't be able to see it. I wouldn't worry about reinforcing that spot and having a failure somewhere else. Unlike a Kitchenaid mixer, I don't think that spot is designed to fail.
I wouldn't trust a JB Weld repair except as a stopgap, but if you wanted to use it to try and reinforce that area before it cracks it's probably no worse than doing nothing. About the only downside is that if the hairline crack is starting to form you won't be able to see it. I wouldn't worry about reinforcing that spot and having a failure somewhere else. Unlike a Kitchenaid mixer, I don't think that spot is designed to fail.