I'm not a professional welder by any stretch of the imagination. I welded my 304 s.s. manifolds together with 308 wire and no back purging. Did have 75/25 Argon& co2 gas. They're still working and crack free after 11 years. Was I just lucky, or is the back purging really not that critical.
This is what "sugaring" looks like when you don't purge the tube. Scabs, scale, damaged material. The weld is weaker. The outside weld doesn't run as nice and doesn't look as nice as one that has coverage on both sides either.
SS needs straight Argon.
![[Linked Image]](http://weldfabtechtimes.com/wp-content/uploads/2021/07/Why-Purge-1.png)
