Some advice for extensive welding

Question:

I’m doing an off-frame restoration on a 1941 Ford Tudor sedan. At this point I have the body off the frame ready for sandblasting, and I have stripped, cleaned and painted the chassis. The floors in the car are rusty, and I will have to weld in a new lower A pillar. 1 know how to gas weld, and have done a little arc welding, but I have never done this type of extensive work before. Do you have any tips before I get started?

Answer:

First, don't sandblast the body. That would probably ruin it. You can either strip it with Automotive and Aircraft brand stripper, or have it blasted with walnut shells or glass beads, but sand will thin, work-harden and warp the body.

Second, if you didn’t amply brace the body so it would not tweak or rack when you lifted it off the frame, put a plastic tarp on the frame and then set the body back on and loosely bolt it into place. This may sound extreme and inconvenient, but otherwise, when you weld in those floor pans and patch panels, you may be welding a warp into the body making it so the doors will never hang right again, and the whole shape of it may look slightly strange when finished. It may be a little harder to work with the body on the frame, but you will avoid permanent damage to the body alignment if you do.

As for arc welding, I would do it the same way I would do gas welding. And that is to carefully clamp the panel into place so it is correctly aligned, and then spot-weld it into place at the ends, in the middle, and then about every inch alternating back and forth to let the metal cool. And then spot weld every half an inch, and finally every quarter-inch.

Then I would finish up stitching the final little gaps first one place and then an other on the panel so as to let it cool in order to prevent warping and deforming. This is a time-consuming way to go, but it will prevent warping and overheating the panels. After checking the weld to see if the penetration was complete, I would then take a flashlight and put it behind the work to check for pinholes. These can be welded up, and then the whole weld ground clean and smoothed.