6g stainless steel tube welding certification

admin

helloI am a boilermaker and i have my 6g tube certification with mild steel and i am now working on getting my stainless tube certification.   I have ran two tubes so far, one i purged on the root and used regular stainless tig rod, and the other i used flux cored stainless steel filler tig rod for the root with no purge. On both of the tests i used 309 stainless steel stick rod for the fill and cap.    I just had a couple of questions1. Is there any other techniques besides a slight weave for the stainless stringers on boiler tubes using the stick welding process?2. What are some of you other welders's techniques for using flux cored stainless tig rod on open roots?thank you guys and any response would be appreciated.Aaron Olsonmiller dynasty 200dx
Reply:Hey bud, i am also a boilermaker out of albany L197, i have 38 contractors, stainless is tricky as you have found out. get away from the FC filler. The common arc test is a purge root with carbon tube and 309 filler wire wire 309 smaw. I run a tight 3/32 gap 1/8th tungsten and either wire, depends. make it so you can lay the wire in the bevel with out it protruding inside. Then just push alittle wire as you run around the tube. With your stick, only weave when you have to, stainless is tricky and you can wormhole it and trap slag very easily. just run stringers, What are you running for amperage?
Reply:hey man nice to see other boilermakers out there, i am from local 11 out of helena montana but i live in colstrip montana.    the president of our local has been helping me out with the stainless and he said to run 3/32" 309 rod around 60-75 amps  so i run it around 70 amps.   I am running stringers but with a slight weave just because he told me you have to do some sort of motion   so i make the tightest weave i possibly can. i have seen the wormhole thing it has only happened to me once when i accidentally long arced it.  i set my gap exactly how you said you do it and it works really good that way.   so far i prefer to purge it and just use regular 309 tig wire   instead of using the fluxcore wire with no purge.     do you just run straight stringers with no oscillation then?Aaron Olsonmiller dynasty 200dx
Reply:sorry for not responding i idnt know there was a reply, you can weave slightly to spread heat out  a little but i typically dont, i run small stringers stacked up. Its hard to say not to weave or to weav, because there are sometimes where you kinda gotta weave and other times when there is no need.... its kind of a combination of the two really, stainless is very touchy, if you dont have a spot for the metal to go, its fall out and look globular and like poop, so you kinda need a groove or another bead to stack against.
Reply:Thanks for replying, i have been practicing on mostly thin wall tubes in the 6g position and i know what you meen when you say sometimes you gotta weave and other times you dont need too. I would like to try a thick wall tube and weld it all the way out with 309. I am hopefully gonna do that when i can get down to the boilermaker training center and use their mill hogs and get a thick wall tube.Aaron Olsonmiller dynasty 200dx