I thought i had it, but I don't. What I have is a warped mess. I welded a piece of sheet (20ga) onto another piece to stretch it, and it warped. I would now like to hear from the metal experts as to how to shrink the high spots. Thanks, Cosmo
cosmo.. what does this thing look like? what are you welding? why is it only 20 ga? lets see some pics..
You're right, too little info. Pics below, second is an edge-on; shows the warpage. It's 20ga to match the sidecar it'll be a part off. It was TIGed, and a **** weld, that I still think I'm pretty fair at. The ribs are for strength, as original, I just don't have a bead roller. Luckily, they'll be on the bottom... Thanks, Cosmo
Wow, that really warped. You may not be able to get it 100%. When welding like this it is usually the practice to hammer each weld segment as it is done, and it is still hot. That way you can control the warping to some degree, as you go, and see how much it warps, as you go. What I'm saying is, it is easier to correct a little at a time, as you go, then to wait, and try to fix the BIG mess. BUT, it can be done. You need to reheat the seam, to cherry red, and then hammer it lightly to beat down the swelling of the seam. Don't beat it flat, it will still shrink a bit when it cools completely. How do you know how much to flatten it? Experience. It'll take you time to learn. You'll probably have to do the entire seam. Being a beginner, you might make it better, but then again, you might not. It's not the type of thing you can master in one shot! Check with John Kelly. He makes a shrinking disc that is easier to use, for a beginner. It may help you a lot!
Give it to my wife, she'll wash it and throw it in the drier... ...always works on my brand new event or Harley t-shirts.
http://www.fournierenterprises.com/MetalQA.html#Q10 Here is a great explanation on shrinking from Ron Fournier.
If I were to have tried that project, I think I would have clamped the edge by using a long piece of angle iron and a bunch of clamps, sandwich the workpiece between that and a thick steel welding table that also acts as a heat-sink, and only do some small s***ch-welds at a time, maybe just 1/2" on each. I might even try some of that heat-fence putty. I think the problem you have there is that you are working on a flat panel at the edge. it has no crown or anything extension to the metal to keep that edge from pulling and pushing as the heat wants to warp it.
you went about it backwards. distortion on the edge and inboard is from shrinkage in the heat effected zone caused by welding.you need to stretch (read: planish) the weld are first. if the panel was properly shaped and fitted beforehand, that should address the distortion issues. by trying to attack the edges, i think you're that just digging yourself further into the hole as that not the cause of the problem. get ahold of Fay Butler's video and this will make better sense.
How about some pictures of the panel next to what you're trying to fit it to? I think you're going to need to start again with a fresh sheet. Nothing is harder than getting warped panel reasonably flat. Check out metalmeet.com. If you post your question there, you'll get a lot of helpful tips. Good luck, Cosmo. --Matt
We went to a shop in Ripley/Cushing Oklahoma this past saturday. The owner showed us to shrink metal with a torch tip that made a tiny (smaller than my little butane torch) flame by heating a tiny spot (smaller than size of a dime) on the fender to glowing red and hammering off dolly and pushing the metal into itself. It worked real well! However, I do agree with what the others said, it really sounds like you need to stretch where you welded to bring the metal back into shape.
you could use a long straight dolly like a length of rail road iron and slowly work hammer on dolly only on the weld areas, planishing it straight.
Kind of hard to tell from the pictures...but you can stretch the welds pretty easily without heat. If you have a flat steel surface, and a small faced hammer (or one with a crown), hammer it over the flat steel. You could re-heat, but I would hammer it cold...more heat can add more shrink. After stretching it back out, hammer it with a lower crown hammer to smooth it. Stay in the area that turned blue from the weld heat. This is where it shrunk. Everything else should pop back into place with only minor tapping after you have stretched. Flat panels are tough! John www.ghiaspecialties.com
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