In need of help. I welding in a patch panel above the wheelwell on the drivers side of my 67 Firebird, spot welding about every 6 inches. At the top right hand corner of the panel on the existing quarter it warped. I tried popping the warped area back out but it is oil canning. I cut the welds loose on that corner and tried pushing out the dent and still it oil canned. Finally I rewelded the corner and ground down the weld and hammered on dolly along the welded joint but it didn't appear to do anything. Any suggestions?