Thanks everyone for the kind words.
I am including a few more tips for welding sheet metal. I have done welding on and off for almost 20 years but it was all with a flux-core welder and it was all structural welding, 6x12 trailer among other things. I found joining sheet metal extremely difficult the first time I tried. I hope some of these tips will help convince some of you to buy a welder and start on a restoration. Prior to this project I had never welded thin gauge metal before.
Here I have made the patch. This time the patch was difficult to make. I had a hard time getting the contour right. I spend almost an hour on the patch, I kept shrinking and stretching the piece but the contour just didn't quite match. I was about to give up an make another patch piece, but one last try and I got the contour right. Use a straight edge to align the patch. I clamped it at one corner and used a magnet to hold the edge flush. I put the first tack weld at the corner opposite from the clamp.
As I said before you must adjust the metal before each tack weld. Here I have remove the magnet and the clamp, you can lift the patch from the bottom if necessary to raise the edge to make it even with the adjacent edge. Lightly tap the metal to bring the edges perfectly even. You are only concerned with lining the edges up for the next inch. Then tack weld it. Repeat the process till you get to the end.
For the end of the patch I clamped the metal to pull it down even. I adjusted the pressure of the clamp to give me the desired movement of the patch. It you notice I used masking tape to hold the clamp out of the way.
Sometimes impurities in the metal will cause splatter and smoke. It this happens use a stainless steel wire brush to brush junk away. You need a stiff wire brush and it should be stainless steel since other types could contaminate the surface. For what it worth the wire brushes sold in the welding section at Lowe's are too soft to be of any use. I ended up ordering mine on-line, since I was unable to find any decent ones at a local store.
After brushing.
Should a ball develop, I recommend you cut it off. Sometimes the extra heat caused by the ball will blow a hole in the metal the next time you start to weld. This would not be a concern it you were welding all new metal.
And the finished piece. All did not go perfectly well, when I bend the edge over I didn't get the bend to align perfectly with the existing panel. I solved this by laying a bead down the edge of the panel and then grinding it smooth. The upper left corner was ground a little too much, less than the thickness of a sheet of paper, but since I am covering the entire door with a skim coat of Rage, this is not a problem.
View from the back side.
Any questions just ask.