I was welding a patch panel in last night on the A. Lower quarter behind the door. I made some holders like the ones Manyolecars shows in the tech section. I've welded patch panels before but I always seem to get some warpage. No mater how slow I weld or amount of time I let it cool I can never get it as well as it should be. I would like to hear some tips from some of the more experienced guys on here on how they do it. My warpage is actually on the patch itself. The middle is pretty good but both endS on the bottom have some pretty low spots in it.Above on the original portion of the car stayed pretty straight also. I did notice the panel before welding it in seemed a little stretched before I started and thought that may have had something to do with it also. Should I be hammering and dollying the weld as I go? It's amazing to me how people like Winfeild and Cole Foster get there metal so smooth before filler is even added.They are masters.
I'm no guru, but here's my 2 cents: Did you MIG (wire feed) weld it? If so then it's kind of hard to hammer weld that way...because the MIG weld bead is too hard, and will not metal work as well as a oxy-acetyline gas weld would. If you have minimal distortion, it can be hammer and dollied out if you're careful not to overwork the weld until it is brittle. Paul Bragg gave me a few tips: He always positions the panel and tacks it with a MIG, and grinds the tacks back. He then slowly welds the seam with O-A, but not hammering as he goes. He says that he got tired of going back and forth and just does his hammer and dolly work after he gets through with the panel. And he always goes back and grinds both sides of the weld before his hammer/dolly work, because it works better when the metal is about the same thickness all over. Now, admittedly, his method would be a little harder for normal people like us to do, so I'd suggest the hammer as you go method when O-A welding. I think you will get a little bit of distortion no matter how you weld it...and if it's as minor as it looks in the picture, I wouldn't feel too bad about skim coating it with a quality filler (like Rage) and spending my time elsewhere. Like I said...I'm no guru, but I pick up what I can.
Any weld will shrink as it cools,which will cause stresses in the panel. Planishing the welds is done to compensate for this shrinkage.
Bass covered your question well. I'll add a couple things. I gas weld sheet metal, I hammer as I go, then finish as needed when the seam is done. You can heat a mig bead with the torch and hammer it to stretch it, but if you have a torch, you may as well gas weld it.
Its kinda hard to see the warpage in the photo and a bit hard to explain ( in english anyway) but Ill give it a shot. I never weld continously across a body panel with a MIG. The best methode is to spot weld randomly anlong the seem until it becomes a continous weld. That way you dont get excess heat on one spot. I dont like to use "hammer welding" as I go. Some like it because it saves some grinding, but I guess it depends what you are used to do. If I get some warpage along the seam, its caused by shrinking due to excess heat. Then I grind the welds flat on both sides of the seam and hammer on dolly along the seam to stretch the metal back to shape.
It was all done with MIG and was tacked and moved around back and forth until all the tacks were together even stopping to let cool before completeing the tacks. I did'nt grind the backside but that is a good idea. I have a torch but have been to poor to ever buy my bottles yet. Bass, I know its no big deal to skim coat it and I am about to get some Rage to try cause I hear its great stuff, but I would realy like to work on working the metal better and get better and try and avoid the warpage. Cause I know I'm good with the Bondo. I can fix anything with enough of that stuff
Looks like you are making steady progress. Come over and practice on the Fairlane. Or let me practice on your A, I haven't tried to O/A sheet metal yet. TZ
Tyler I try to do just a little something every night, even if it's just makeing a pattern for something. All the panels that we bent are cut an fitted and I will probably get them welded in this weekend.
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