I have had much luck with cheap MIG welders, but I recently acquired a small Lincoln MiG that my brother used before he passed on. So I discovered that one of my catalytic converters as a small pinhole in it where a shield was spot welded on there. I hate to have to buy CATS, I was thinking of trying to seal it up with the MIG welder. The CATS look fairly solid and I don’t know if they’ll hold up once I start putting the welder to it. Has anybody tried to weld on catalytic converters before? Any tips? 
