Richuk

I'm having a set of C5 magnesium painted at the body shop, The guy said they need welding as they all have hair line cracks, He said he can have a specialist weld them no problems, I'm just wondering if they will be safe to use, Won't they just crack again if all the wheels are cracked already?
Can't afford to just bin them and get other wheels, should have known they were cheap for a reason!

Thanks