Contrary to popular belief, metal doesn’t stretch or expand when it is heated or welded, it shrinks.
When the metal shrinks it loses surface area which is why you have a huge low spot.
Farther heat shrinking is only shrinking that metal even farther and taking you away from where you want to be.
The ONLY repair for this damage is to stretch it back out. You need to get a hammer and dolly or some type of metal bar or spoon and get it behind the seam. From the topside you hit the dolly (which is underneath the weld seam from the inside of the door) with the hammer which will stretch the metal back out, thus removing all your warpage.
Since the ONLY physical change you made to the metal was at the weld seem that is the ONLY area you need to address. All the surrounding warpage is a DIRECT result of you welding and the metal shrinking. You focus on stretching the shrunken metal back out and the warpage disappears. The warpage around the weld is simply there because the shrunken weld has placed tension on the panel and the metal has to give somewhere, thus the creation of warpage. Remove the tension, the panel relaxes and the warpage goes away.
You stretch out ONLY the weld seem and the HAZ or Heat Affected Zone, which is the area surrounding the weld on both sides which turned blue. This metal is the shrunken metal and the ONLY metal you need to focus on.
Use the hammer and dolly and hit the dolly directly sandwiching the metal between the two effectively stretching the metal back out to its original contours.
Now if you heat shrunk other areas then all bets are off.
Last edited by sevt_chevelle; 06/04/2010 10:47 PM.
