Need alloy rim repair in so cal

I’ve got a set of 2 piece weld racing rims of which 2 of the 4 have developed cracks within the weld and are leaking air. Don’t wanna ditch the rims cuz I love em. Anyone know of a good rim repair shop or welder/fabricator in Orange County that has experience with this type of repair? Or has anybody else had this problem with 2 piece alloy wheels that found a successful fix? And if so, what was it? I can remove the tire myself and do all but weld aluminum, just not sure if there’s a known fix, but seems there should be, as I’ve learned this is a pretty common problem with 2 piece alloy wheels. Thanx in advance for any help offered