Suspect this is WAY off of what you are looking for but I am just getting started on welding the chassis from my '30 Model A. The chassis could warp or move around due to heat from the welding when boxing the chassis so I looked on craigslist and picked up a 14' steel I beam for $40. Tacked the chasiss to that to keep it in place and prevent it from moving. Probably horrible overkill for what you might be doing, don't know as you didn't detail what you would be welding.