Better be a certified welder fabricator and know what the hell your doing if these roll bars are for competition use, if not you could find yourself in some big trouble, If you build one for yourself and it passes tech at the track then fails in a wreck you aint gonna sue yourself, see where I'm going with this? As to your question, I can get you in well under $4.000, in fact I'll be putting one of these on a new service truck being built, pretty cool state of the are rig, Obviously you'll need to figure it all out but with practice you'll do fine,
http://www.ebay.com/itm/Miller-Multimati...
It's easier to make good welds with MIG for the novice which I assume you are or you wouldn't be asking.
Yeah... So. I'm happy for you. Now, what's your question?
So far you have made a statement, but you haven't asked anything.
My knowledge is fairly basic but I thought it depends on the metals that are to be welded, ie TIG is used for nonferrous and MIG on ferrous metals
Im looking into buying a mig or tig welder to weld roll cages,manifolds,auto-bodywork,performance parts, etc....budget is up to $4,000
