Originally Posted by outlaw256
Originally Posted by curtisreed
I have done quite a bit of TIG welding so here is my opinion on a couple of things asked here.
Originally Posted by todd8525
Not sure but i was told u are not suppose to TIG over a MIG weld?Yes /No or is this a myth.
I believe the issue would be if the whole thing were MIG welded and then ground down / or not, then TIG welded over because the TIG is such a smaller weld bead that you would not get weld penetration to the base metal only into the weld already there.
Originally Posted by outlaw256
dont have a tig welder here but i gotta hell of a big mig. we have built frames amd everything else you can think of. why is tig now the only way to go when mig was it before. someone with a gun in his hand that knows how to weld can weld a frame up just as good and strong as tig welded.imho...
I think because moly tubing is so much more prevalent than in the old days. Tig does provide a smaller nicer looking weld in the right hands and MIG is not recommended on moly even though it can be done. It is a little harder to tell the penetration of a MIG weld also.
Curtis
well curtis thats a good answer. and you are right about that. but ive built frames and for hotrods and racecars with my mig and we have them all stand strong for yrs. i made a roll cage back in the mid 80s that got a true test in a 57 chevy ,buddy rolled his streetracer at 100 mph and walked away with a hell of a headache but he walked away. yeah tig is pretty but is it really stronger. that doesnt make any sense for it to be stronger if you really break it down.
I don't think the strength of either is in question. Both will hold until the base metal tears. I should have qualified what I was saying by adding that the TIG is mandated on Moly by the HRAs. They certify the cages and you can tell a good TIG weld from a bad one easier than you can a good or bad MIG weld. I'm just talking Moly here. I am only so so with a MIG gun in my hand but I know guys who I would trust my life with to MIG a cage for me on Moly tubing. I, on the other hand, only trust myself to TIG Moly.
You are absolutely right about the strength of MIG welds being safe though.
Curtis