Always use purge gas on stainless?

Hey Nigel, Just wondering if you always run a purge when welding stainless steel tubing? ie if your doing intake or exhaust piping or do you only use purge on things like exhaust manifolds that will be under high stress / heat.

I generally do not purge on my intake piping but clean up the "sugaring" on the inside after the welding where I can and not had a issue yet but yea just wondering if that's how everyone else does it.

Hi Clint. I don’t purge everything as it gets a little expensive. Headers would be the only thing that I purge, most of my stainless if fusion welded and has very tight fit ups with low amperage small welds so the sugaring doesn’t happen on the inside. Of course these welds are not the strongest but in saying that I have never had a failure. Thanks and happy welding!

Justin at The Fabrication Series - check it out, been following it for years - has a couple of videos that may be useful for you -

https://www.youtube.com/watch?v=AIRWMhoke9I

https://www.youtube.com/watch?v=K4aVdZwjASA

Can't comment, personally, as 99.99% of my welding was stick, gas or MIG on steel.