Warped Metal with MIG

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I'm having a problem with warping when doing long MIG welds on 1/8" sheet steel.  Anticipating this problem, I did 4 1" stitch welds on the back side of the piece as shown in the first photo.  The main weld is about 6" long, and I set my Hobart 190 for V = 3 (about 18v) and wire speed about 230 imp.  The metal, which was loosely clamped to my worktable, was perfectly flat before these little welds, but afterwards it bowed slightly to give a convex surface on the back side.  Hoping that maybe welding the front side would even things out, I did the front weld in three parts about 2" long each, in the order 1 - 3 - 2 as shown in the second photo.  Wouldn't you know, it just made the bow even worse, so that the front surface of the piece is concave.  At the edges, the center is a little over 1/16" higher than the ends, as shown in the third photo (back side is up).  Any suggestions on how to avoid this kind of problem in the future would really be appreciated! Attached Images
Reply:tack up ..small welds on one side and flip weld and rinse and repeatYou just have to learn how to play heat..1/2 in weld flip on same spot 1/2 in weld move to another spot and repeatBacked my CATMA over your CARMA oops clusmy me  What would SATAN do ?? Miller Trailblazer 302 AirPakMiller Digital Elite  Optrel Welding HatArcair K4000Suitcase 12RC / 12 VSHypertherm PM-45Rage 3 sawRusty old Truck
Reply:You also might want to use a backstepping sequence on your welds. I have found that in some cases that backstepping will mitigate for warpage. Here is a link that describes the technique and also some other helpful tips on controlling warpage and a checklist at the end that will help you minimize distrotion. Hope this helps!!http://www.lincolnelectric.com/en-us...on-detail.aspxInsanity: doing the same thing over and over again and expecting different results.
Reply:Originally Posted by killdozerd11tack up ..small welds on one side and flip weld and rinse and repeatYou just have to learn how to play heat..1/2 in weld flip on same spot 1/2 in weld move to another spot and repeat
Reply:Originally Posted by BEZ66You also might want to use a backstepping sequence on your welds. I have found that in some cases that backstepping will mitigate for warpage. Here is a link that describes the technique and also some other helpful tips on controlling warpage and a checklist at the end that will help you minimize distrotion. Hope this helps!!http://www.lincolnelectric.com/en-us...on-detail.aspx