Oddjob

I am repairing some accident damage on a car. The frame has been pulled straight but there is still some buckled sheet metal, and some of the spot welded seams have opened up somewhat.

I am looking at reinforcing some of the structure and stitch welding a few of the problem seams.

For guys/shops that have seam welded tubs for the race cars, how much concern is there with heat warping when welding the sheet metal seams? I dont care about local distortion, but I dont want a frame rail or shock tower to get pulled out of alignment.

Any recommended technique?

Geoffrey

I seam welded my entire chassis similar to how Riccardo did the GT3RS tubs that were outlawed by ALMS. I used a TIG torch for most of it with some MIG welding in areas that I could not easily get to with 2 hands. It did not warp the chassis, however, I did weld one small area, then move to another area rather than welding an entire seam. You should be fine.

I also used a rotisserie to weld the car on (which did not bend or warp the chassis during the process) which made it easier. The chassis was also acid dipped to remove the seam sealer and undercoating as it is very hard to weld with "dirty" metal and the fumes are toxic. I would not try welding the car without both acid dipping and a rotisserie.

DrJupeman

Geoffrey, good stuff!