How do I properly prep pipe?

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I am working on a turbo setup for my car. Question is-after I cut my tubing, mild steel, and bevel it on my grinder, the bevel is rough and "grainy". My arc, lincoln tig 225, is almost like a flame, not an arc. Can this be caused by my "grainy" bevel ? And, if so,  any suggestions on how to better finish by bevel to make it smooth ? Thanks,Dave
Reply:contamination will change the color of the arc.  Either grinding dust on the Tube, or contaminated tungsten.
Reply:So the "grainy" look on the bevel is not the problem?
Reply:I don't think so, but grinding dust or paint dust or dirt even getting trapped in the grinding marks could be the cause.  I have seen burs left hanging change the arc. Maybe try a flap wheel to smooth everything out and then wipe it clean before welding.  I use windex on a rag to wipe down stuff.  Give it a few min to dry and then weld away.I'm sure somebody else will chime in tomarrow and either say I am full of it, or agree...
Reply:Not knowing your level of expertise so don't take offense. You're using DCSP, argon, sharpened tungsten with the grinding marks on the tungsten along the axis of the tungsten not radial ?.....Mike
Reply:Yes to all MrMikey. And my level of "expertise" is LOW.  Thanks,Dave
Reply:What is the wall thickness of the tubing you are using?You likely can weld it without any bevel. Gap free butt joints are the way to go with thin wall tube.Rex
Reply:You need to run DCEN NOT DCEP.  Which means you will run your torch to the neg. terminal on your power source. The grainy bevel wont cause that "flame", I would guess that your polarity is wrong, Wrong gas(need 100% argon), or some sort of contamination. Hope this helps.Go hot, or go home!
Reply:I am practicing on .120 wall but will may change to .060 wall as .120 might be overkill. Not sure if it is going to support the turbo yet or not, that will be the deciding factor. Is it ok, or recommended, to butt weld with no gap on this wall pipe?Thanks,DavePS- I checked and the machine is set to DCEN. Sorry for the confusion.
Reply:Originally Posted by mrmikeyYou're using DCSP,
Reply:for 1/8 " id say no bevel, no gap.. short arc   to get a puddle right in the corner and you got it..feed the puddle and move...