zombiedatsun
+1y
3/16 is a good thickness for frame work. Front bag mounts,notches, etc should be no thinner than 3/16. If you plan on doing a subframe,which I doubt, go with 3/16 to 1/4 2x2,2x3,2x4.... Just patching up a spot? 3/16 will work fine. I'd read up on welding before I dove into it. I say this only because you ask the same questions every beginning welder asks... Good luck with it.