Here some more pictures of what I completed yesterday. Some of you were wondering about burning the new foam under the welds. the 1" strips of sheet steel I placed under the seam kept the heat down so the weld never touched the foam. Plus a wet rag right after the spot weld keeps things cool and helps with possible warping.
Here is my mig welder that I will be using for the job.
This picture shows the cooler welded up before grinding the welds smooth. Notice how I alternated the welds to control heat distortion.
Here is the small grinder I use for detail grinding.
Here is the final picture after welding and finish grinding. The picture on the right shows the seams didn't line up perfect but will be corrected during bodywork.