Fixing radiator

I noticed last evening that the radiator in my duster has a small leak in the lower/driver side corner. Looks to be coming out of the seam. It's a 1974 duster that came with a/c so it's a 26inch. I really don't want to spend over $200 for a new one. Is there a simple fix to this? I heard that "JB Weld" does a good job on stuff like that. Has anyone ever use that stuff on similar repairs? Im sure it wouldn't last forever though. Thanks.