CWB Mig Help

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Hi, Im new to the forum but I have been lurking here for a while.  I decided to finally post something up and of course, its asking for help.  I have to do a series of CWB bend tests for my college course at Cambrian in Sudbury Ontario.  I am having difficulties with small failures at my restart points and am looking for some input.  The plates are 3/8" thick with a 1/4" backer and 1/2" gap.  This is the flat position and Im using a pushing technique with 3 root passes.  I have already passed these with stick but mig is giving me trouble.Settings:Lincoln Invertech Pro26 volts260 ipm wire feedMig Mix Gold 90-10 gasMy professor has suggested only 2 root passes but i feel more comfortable with 3.  My only problems seem to lie in the restarts, the rest of the welds are good and my face bend is flawless.  Thanks for the help and sorry for the picture, it was the best that turned out. Attached Images
Reply:hey fellow sudburian  the less root passes the better...i just recently re did my tickets and in the root, i crank the heat and the wire you want both edges burning in and see the corner melt away. then turn down the heat and wire for the rest so you don't get undercut on your cap!this is what i do, but that way you know there will be no corners to open up!Is mike Penny still there? great teacher.
Reply:try 26 - 27 volts and 350 - 375 and see what happens
Reply:Thanks for the tip, I'll have to try 2 root passes next week.  I dont have any problems with the corners opening up and I can see the edge of my plate and the backing bar melting during my weld, my problems are in the stop/start area and the defects are minor but still large enough to stop me from passing.  Brian Penny by any chance? If so, yep, hes still here and a damn good teacher too.
Reply:yes, yes it's been a while.do you startright at the crater? try on your weld before the crater and pause on your crater for a split second!
Reply:can you take a pic of you next coupons?
Reply:Sure can, i ment to take pictures of these ones but the camera died... Im starting at the back of the crater, holding and moving forward but the teacher is telling me this might be causing my problems by allowing the weld metal to get in front of the wire and by causing too much buildup.  Im not too sure but this is begining to frustrate me, stick was a breeze but mig is giving me a hard time and I need to get it sorted out so I can move on.  Im assuming you also went to cambrian...Did you take the fitter or fabricator program?
Reply:welder fitter a few years back.
Reply:if William Day construction will send me I wanna go back to get my journeyman's ticket (red seal)
Reply:Does the mig welder your using have a runin adjustment? If so try turning the runin up to help with the start of your welds.
Reply:No such luck, no run-in.  Im going to try it a little hotter next week and see how it goes.
Reply:Originally Posted by SledneckHi, Im new to the forum but I have been lurking here for a while.  I decided to finally post something up and of course, its asking for help.  I have to do a series of CWB bend tests for my college course at Cambrian in Sudbury Ontario.  I am having difficulties with small failures at my restart points and am looking for some input.  The plates are 3/8" thick with a 1/4" backer and 1/2" gap.  This is the flat position and Im using a pushing technique with 3 root passes.  I have already passed these with stick but mig is giving me trouble.>snip<.