29 Model A truck cab. Problem #1: Both doors have similar stress cracks (the crack in the pic posted was "repaired" by a PO). I did a search and a somewhat popular consensus is to just mig 'em shut. The other answer seemed to be to cut out the stressed areas and replace with fresh sheet metal. Since I have 3 or 4 of these cracks (most at least 2-4 in. long) in what I would consider a high use/stress area, does anyone want to chime in on the best way to repair this area in this particular instance? Problem #2: Most of the hinge hole threads are worn out and have already been tapped to 1/4-20 once. Should I make a template, mig 'em up and redrill/retap, or would just using a helicoil work and hold up long term? Thanks...
First off, you don't want to mig the bolt holes and think it will be easy to redrill and retap. It will be too hardened. Just looking... it seems the backing plate is pretty simple. I'd cut the whole mess out. Fab a new heavy 16 ga backer with welded nuts. Get that in there properly and test fit to car, and then reskin the outer piece. i had to do all that to my 32 when some ***hole went with suicide doors. They messed the car up so bad, they quit. By that time, all the hinge pockets on doors and pillars were gone, so I made them.
F&J: Yeah, I was wondering about how hard it would be to retap if I migged (a mig is all I have), but wasn't sure. I like your idea of redoing the backer if I have to, but was looking for another way out (and that doesn't just mean I'm lazy) Was also wondering about using a helicoil. It's easier, but I'm not sure if it'd hold up OK... Thanx
Actually, I think it would be quicker to make a new backer. But don't weld it in first. I'd trim off all the cracked outer skin. Then make the new backer out of thicker metal, that can hold the welded nuts good and strong. Maybe even 14 or 12 ga, whatever you have. Make that new plate a bit longer/wider than the large opening you just made. That is so you can remount the door with just the backer during tacking... Make a quick shim that will be as thick as the final outer skin, so you can test fit the door to the cab. Put the door back on and move the door around until it fits the cab perfect. Have someone hold it steady while you go in the other door to sneak into the door to tack weld the backer. Check the fit before final welding. Then do the outer skin redo.
Thanks, F&J, I think I have my answer. Appreciate the step by step. It sounds easier now than it did before. Many Thanx! Chris
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