I tried welding in a patch 12x 4 16 ga in the box side of my 58 with my 135 Lincoln mig. I used***** welding clamps and tack around the outside edge. I then started filling in with short beads and I managed to warp the panel. I had one friend tell me to cool the weld with an air blow gun. I have seen another fellow use a damp rag and then hammer the weld. I am not sure why I would want to cool the welds faster? Could I heat the area that I welded and hammer the section flatter to get rid if the distortion? I am having difficulty figuring out what is happening and what do I need to do to correct it. Do I need to remove the whole patch or just relieve the pressure on the 2 long sides? I am interested in other peoples techniques on welding a panel. Thanks
Welding sheet metal is like boxing "stick and move"! Y ou will want to do single tack weld and alternate positions. Be careful of temp. I would wait until the area that you are going to tack is cool enough to touch. It takes forever, but aside from using a block of brass, or something like that I don't know a way to keep it from warping. Also cooling it with water could have a chance to harden the metal, making it brittle. In short, I would avoid running a bead on sheet metal, no matter how short.
Not sure what the fix is, but I have been told that you NEVER run a bead. You do it by tacking. Tack tack tack tack untill you are finished. Even if it takes you all day. A thousand HAMB members can't be wrong.
i dont use any clamps that leave a gap i***** it tight, tack it every so often and then run a bead between the tacks the shrinkage that creates the warping is only right at the bead if you have a small enough bead you can hammer it flat and dont even need to grind the hammering will stretch the metal back to shape and should fit just how you had it beforehand this is how i was shown to do it Zach
Depending on the amount of crown in a panel, your level of experience etc, you can run a bead if you use a tig or oxy-acetylene welding. But you always have to stretch the weld area no matter what welding method you choose. This article (with links to others) might help: http://metalshapers.org/101/jkelly/index.html John www.ghiaspecialties.com
Four tacks and go do something else, when it's cool enough to touch with bare hand repeat the process until completly filled in.
I find if I unclench my cheeks I get a much better result geddit...."butt" welding ???? forgeddaboutit
I only use tack welding, let it cool and move when doing a panel, no matter what. Sometimes (and I am NO pro) its really hard to avoid. We are dealing with some long flat panels and you dont know whats happened to it in a past life. I was dealing with a door on my Merc where the metal was just already streched and I couldnt for the life of me get the welding done with no warpage. Just take it slow and let it cool is my 2 cents. When I was welding the chop up I tried to keep moving all over the place, even tail lights! Hit here, move a couple feet away, and keep going. Id touch it with my bare hands around the weld and feel it cool before I hit it again.
Okay looks like I went too fast. I'll cut it out and try again. I'll try hammer the tack welds as they cool as well. Thanks
And NO you do not want to be heating and hammering on the weld, it is shrunk, and adding more heat will only make it worse!! Grind your welds down just proud of the base material,, both sides if possible and grab hammer and doly and start working the weld and only the weld. Dont cut it out,, just start working what you got and see what happens.
Keep 'em clinched, please! We don't need none of that around these here parts!! I've seen on this site mentioned about a special wire to use in a Mig welder that hammers easier...it might help but I can't remember the name... Dave
Tman's got your answer for correcting it above. Everyone else has you on the tack weld track. But, after tacking, hammer the welds.
Also remember that grinding also adds LOTS OF HEAT! I took a lot of time tacking the roof on my Model A, but when grinding the welds, it got pretty hot and started to bow. I stopped and hammered a little bit and got it back in place. Made sure I used the grinder in short bursts when over the sheet metal.
Never had much trouble with this until yesterday - was working with a really hammered (stretched) quarter panel. It was really thin! Looked like I was fine, then suddenly I found it warped! I have a big mess to clean up today... So thanks for the tips here.
all of the above is good info..what I do is cut the wire off after every drop of weld...and believe it or not, the best job I ever did was in the cold of winter....we get a lot of that in Cold, Snowy Michigan... I read a hundred years ago that you could mount an air blow gun to the MIG torch with some easily fabbed clamps...for cooling purposes..I never did that but it has merit... now I understand that the New School guys just glue in a metal patch....that would kill the warpage issue....
oh, the grinding issue...Ron Covell, "Professor Hammer" taught me to use a die grinder with a cut off wheel to knock the tops off of welds..there is a lot less heat using this method rather than the traditional grinding disc...I ended up filing the welds down after I got it close and it looked damn good
like everybody else says tack only. i use a air nozzle and make sure i can touch the metal barehanded. also i make the metal fit as tight as possible. one other thing i turn my wire speed way up so that as soon as it tacks it's done. if that makes since. i am by no means a metal worker. hope this helps.
i was always under the impression mig welds were too hard/brittle to hammer - if you are going this once they are ground down im sure they will crack.
By***** welding, I'm****uming you're putting the patch at the same level as the surrounding solid metal. Are you leaving a thin space (3/32") between the patch and the original metal?
I use this order: Tack the peice in place. The tacks are just that, just enough to hold the panel. Weld 1/2in. spaced at least 1in apart. Grind the welds down and hammer on dolly to stretch. Then start over. When you make a weld the metal will shrink. If you make a weld and don't hammer-stretch the weld you trap the shrink from the first weld. Then the second weld will compound the first and make waves in the panel. You can sure try hammering the welds and try straightening out what you have, but don't be afraid to cut it back out. I recomend using a practice peice to get an idea how much stretch you need to put in each weld. Once you get an idea what you need for stretch you just need to be consitant with every weld you make in the panel. One more thing. If you are making a but weld make sure the patch you are putting in is the same thickness. It'll mess you up if it isn't. Jeff
I used ***** welding clamps for initial fit, I think they might be 5/32 spacing. both are 16 ga. I also tried clamping a piece of heavy angle along the panel, not sure if this will help. I also discovered by accident that the thin cut off wheel that I have in the grinder nips the top off the welds quite nicely. So I am tacking and hammering the spot welds and then after 10 or so tacks using the cut off wheel to nip the top off of any that are quite high. So far so good.
also to bring the welds down after ya hit em with the cut off wheel use a 3m roloc on an air powered right angle grinder instead on the grinder. much much kinder to the metal
I have heard that the corners of a patch (assuming it is square or rectangle) should be radius or rounded off rather than pointy. I guess this helps spread the heat rather than having the corners with a bunch of tight tacks. Anyone care to comment on this?
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