Back gassing while welding stainless

[b116757]

Guys

Just posting this to try and help out guys just starting out welding stainless. I normally back gas stainless with a second regulator taping off the backside to hold the gas where it's needed running the hose from the regulator under the tape and turning on the gas very low for 30 sec to minute before starting the weld to purge the oxygen and leaving it on during the entire weld mostly do to my questionable tape jobs at times, this is the preferred method to prevent burning the backside of the weld causing the black sugaring of the stainless that is not sanitary. I have also used Solar Flux type B it is a very fine powder that is mixed with methanol alcohol into a paste and applied to the backside of the weld liberally it hardens to the point it is like glass after the weld and must be removed which is bit of a pain but it does do its job and prevents back sugaring from happening.

[Bucket Head]

I know about back gassing techniques but not the paste procedure. Is the flux and methanol sold at the welding supply or did you have to search for the methanol? Just how much of a pain is the removal? How did you remove it? What tools? Any solvents needed? Or just sand paper and scotchbrite and a lot of sore fingertips? Lol.

Steve

[b116757]

I used putty knife to remove the residue if I remember right. The directions for the Solar Flux type b call for alcohol (methanol) preferred I think I used the Red can of Heet 99% isopropyl and it worked fine

[esetter]

I have also used a thick piece of aluminum or bears clamped against the back side to absorb heat. This will also prevent sugaring when applicable.