Quote:

I am fabbing up some upper control arms out of moly tube. Would it be safe to mig weld the tube ends and ball joint part on with mild steel wire?



Sure, you can use a ER70s-6 wire for that... be sure
to drill 2 holes in the tube (one on each side) so
when you insert the threaded insert you can do a puddle
weld to it(hope you see what I'm saying)