Reverse polarity open root 6010??

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Do any of yall pipeliners out there use (DC-), or reverse polarity to put in our stringer beads, and then switch to positive for hot pass, fill, and cap. I have never tried this method but have heard of people doing itComments on pro and cons
Reply:Reverse polarity is correctly identified as DC electrode positive. DC- is electrode negative or straight polarity. never saw nor heard a pipe liner use any thing but DC electrode positive for SMAW  pipe. Work with some sheet metal workers who  ran 6010 and 6011 on DC- but they were working non=-code.
Reply:DC(-) or straight polarity is very common for EX010 root pass welding on pipe overseas.  I've used it/worked with it for myself, but never for any code quality work for anybody else here in the states.  I don't think the API/AWS/ASME codes allow the welder to chose polarity.  It what the engineers call and 'essential' variable in the welding process.  So I wouldn't recommend experiementing on the job.  All of the WPSs I've seen from this country specify DC(+) for the root pass.  It's the way I was taught to weld with E6010 as well.That said, I think straight polarity(-) roots with EX010 are easier to weld downhill than reverse polarity(+).  The arc is smoother, and ties into the bevel easier because that's where the heat is concentrated.  I have a suspicion that the root deposited is thinner, but I've never checked the cross section to be sure.  I'm pretty sure this is why you're supposed to switch back to reverse polarity(+) for the hot, fill and cap.  I think the deposition rate is much higher with reverse polarity, which is good for productivity.  The one time I fooled around with fill and cap on straight polarity, I didn't like the way the puddle acted; not one bit....Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:o ok so reverse is known as positive thanks weldinglifer, i did not realize. i looked it up last night and learned that negative ( straight ) polarity on a root pass minimize burn through and reduces internal undercut.  interesting concep to me, but i shall never try in a code situation ( thanks for the warnings fellas ). helpfull reply A_Dab thank you