gas welding vs mig

[MP&C]

Originally Posted by pimpston65

has anyone used gas welding with this welding for 18g panels as well as mig welding. i have very long sections to weld, and most have no access to the backside. so my issue is distortion control. so the question is, does gas welding do a better job for my application? thanks for replies...

If you can do a no-filler fusion weld, the OA or Tig does a nice job, but I think gravity helps any welding on a horizontal plane to sag a bit, looking like an undercut. Once planished, it will tend to fill in any voids that you should see a fairly flat panel, both front and back, requiring little to no filing/grinding. The caveat here is that you absolutely need access to the rear side to be able to planish.


What areas are you welding that do not have rear access?