mig -- hard brittle
tig -- not hard or brittle
tig is the what to go on a cage -- self normalizing
Not necessarily. A bad TIG weld can be brittle and a good MIG weld is not brittle. The effects on the material welded have more to do with material type, thickness, weld type (butt. filet, corner, lap) filler material and the skill of the operator to not only apply good technique but to also be able to properly configure the machine. Filler for general mild steel that would be used in this app for either TIG or MIG is identical in composition but varies in form factor. The strength delta in this app the difference between TIG and MIG is so minute that it's not discernible. This is the same thing they teach at the
Lincoln Electric Motorsports Welding School, Hobart Welding School and
the college where I'm working on getting my welding cert.
Roll cages are a bit thicker, .095 to .120 and mild steel reacts favorably to either process as long as you have a competent operator. There are other apps when either a TIG or a MIG have a greater advantage though in a cage or chassis app MIG is fine. In fact that's what most commercially available cars use though some are build using TIG for example drag cars under a certain time are required to have 4130 TIG welded cages. Here's a bit I found about rac car welding a while back a couple years after I'd picked up welding again.
There always seems to be controversy about MIG (metal inert gas) versus TIG (tungsten inert gas) welding. According to the welding experts I have conferred with-and I have conferred with many, mostly in the Aerospace industry-the general consensus is the difference in strength is mostly academic. The main points of discussion centered on the material being welded and the complexity of the weld joint. If we focus on steel and the types of joints used in race cars, in a correctly performed weld, the difference between a MIG and a TIG weld is almost nonexistent from a strength perspective. The same can be said for aluminum in a race car context.
Read more: http://www.stockcarr...l#ixzz1dAkreqbI