Another way using gas-welding that I have posted before (I think) is tack weld every inch or so, quickly fusion weld the seam without worrying about penetration, then tap the weld back into place with the surface contours, flip the panel over and do another quick fusion weld on the other side, then stretch, smooth etc. This is very fast and you get perfect penetration. Very little if any undercut because you are moving fast and not worrying about penetration so you can make a weld that is pretty on the surface. If there are small areas of undercut, I just go back and add a little filler rod, tap the metal out again etc. This only works on panels you can weld both sides of, of course. Attached pictures of a fender flare I made this way. John www.ghiaspecialties.com
David saying there is little to no distortion,Come on. You have a 1 1/2'' headband,you will never convince me there is little to no distortion. I watched your preview video and 3:57sec into it you are welding in a patch panel.I look at that panel and to me personally it shows just as much distortion as I would expect. That is why you are beating the hell out of it with your slapper.You are re-stretching the heat effected zone.I am not saying that is wrong,as a matter of fact it is totally right.As long as you re-stretch the haz it is all the same. I weld a inch ding ding ding with the slapper.You weld 24'' clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank clank and so on with the slapper. I think you have been doing it so long,working a panel has become second nature and you just think there is little to no distortion. For me just being a rookie,I would rather keep up with it as I go so I do not lose control of it. Seriously watching you with that slapper kind of scares me,I have never hit a panel like that.... ever. You make it look to easy.
I don't particularly care for the undercut on the weld myself. Even if it's good and strong, you're still leaving things in such a shape that high build primer or a glazing putty is required, instead of just being a last resort touch-up kind of deal. There's no metal finishing a seam with an undercut like that, and you'll always have an undercut unless you lay in some filler.
Chad I enjoyed your article about mig welding. When you say get out the 1/16" ZipCut do you mean the tool that is used in drywall finishing to trim out around electrical boxes, windows and doors? The thing is like a mini router. What type bit would one use?
Chad I enjoyed your article about mig welding, but have a question. When you say to get out the 1/16" ZipCut to do knock down the weld do you mean a RotoZip ( a type of mini-router) used by drywallers to cut in around electrical boxes, doors or windows. What type bit would one use?
Chad I enjoyed your article about mig welding. When you say get out the 1/16" ZipCut do you mean the tool that is used in drywall finishing to trim out around electrical boxes, windows and doors? The thing is like a mini router. What type bit would one use?
Johnny you are right about the distortion. I don't think David means you get no distortion, he means even distortion. I welded about 12 inches straight through without chilling or stitch welding. I did tack the panel. The tacks are a little shitty because I fused the 2 panels pulling them together with 1 hand and running the torch with the other. You get shrink from the tacks and each tack pulled it in further making it tougher to pull together. Unless I just didn't have the panels fit good enough. They sure looked good on the buck prior to welding. I just run the weld full length without stopping. It sucked in a good 1/2 inch. It was an even 1/2 inch. It was no problem to stretch back out and metalfinish. I managed to weld a good 8 inches in the center without filler rod. It was the easiest part to work and ran through the wheel without a bump. It was nice to not have to deal with grinding the weld in that area as well. I'll use David's method when I can, but I just feel the need to terminate the welds the last 1-2 inches with filler rod for my own peace of mind to avoid edge cracks. The finished weld after wheeling. I had about 35min. into finishing the weld at this point. Sorry about the dark picture. I'll post more pictures as I get some practice. Or maybe the next weld I'll use the tig to compare the methods. One final thought. I thoink if the weld was going length ways through the panel the shrink from the weld, if even, would cause alot less distortion. Jeff
I tried it again today. I think the fit of the panels really screwed me on the first weld. This time I fit the panels loose, or a little high on the weld seam. Sort of a prestretch setup. It went very well. My pictures are really sucking bad though. I need a new camera! The panel stayed flatter and I had less time yet finishing the weld. I started the fender lip around. It helps in positioning the fender on the buck, and the fender is easier to work with. I've found the closeup pictures are the problem. More pictures of the fender here: http://www.jalopyjournal.com/forum/album.php?albumid=8333
Johnny I must confess I did not read this thread all the way through when I started posting on it, I just saw the thing about annealing steel using soot as a guide and the teacher in me made me reply to it!. So this is a belated thank you for posting the above link Johnny, the thing I have been trying to put over all these months is that the welding process is just part of the entire process. The rear quarter you see on the youtube footage is part of a demonstration of this process, most of the distortion you can see on that panel is from heat shrinking a deep dent which was further up the panel near the wheel arch. I have never said that it is possible to weld everything with no distortion, part of the process as I have said on many occasions is to have the skill to make your panel and know where to join it so that least distortion is caused, the gas welding process I show allows the weld to be plannished or wheeled back to shape without further work. In some instances on high crown panels no distortion is caused, on most the distortion is minimal, on the rear quarter the area is almost flat and I honestly don't think you would get that result with mig. I say on the DVD that there is not much to chose between Gas and Tig but I have some reservations about tig welding without filler rod and of course as soon as you use filler rod you are back to slow welding and having to grind the weld (unless you are superb at tig welding sheet) Tig welding without rod is what the guys at Contour Autocraft teach but they are welding new metal. That is another advantage of gas it will weld just about anything. The photo I posted of the underside of the weld is a new section of steel welded to the original 1938 wing. Another point I would like to make is that the gas welding process I show is easy to learn and I have taught hundreds of people how to do it. Most people who have never welded will be able to get results within a few hours and with a couple of days practice can weld as good as me. Its not hard! Tig welding with filler rod is another thing altogether. One point I would add is that once you can weld in this way it becomes easier to add a very small amount of filler rod if you wish, I don't because I cant see the point unless the panel is going to be chrome plated. The cost of setting up with an AC/DC tig is a lot more than setting up with gas and once you have gas you can weld ally - In fact gas welding ally is far better than tig welding ally for panel work. David
Jeff The wing is looking good. Thank you for at least giving this welding method a try!. That buck you built is getting good use then! David
Chaz This is one advantage of gas over tig that I had never thought of! Thank you for buying the dvd I am glad you liked it I am even more please that you have made a good recovery! Regards David
Very informative reading! Thanks to all who have contributed. I am using MIG since it´s the only thing I have and have a question about shrinking with heat. When repairing a dent (for example on a door) can I make the hotspots to shrink with a MIG. You know, just weld a spot on the door skin to generate the hot spot or does the mig wire add material to that precise spot so much that the heat doesn´t generate the desired shrinking? Jukka
It may be possible to do this by holding another piece of steel tight against the panel and welding onto it, the heat will transfer through the steel into the panel. John Kelly will tell you a way of shrinking without a torch which is very controllable, using a shrinking disc. If you watch some of Johns videos on youtube you can see him do this.
David the second weld went much better. I should have spent more time fitting on the first weld... Once I get the camera figgured out I'll post one more weld. I plan on making it in 2 halves and welding it right up the center. You are irght about placing your weld in an area that gives the least amount of distortion! I've been looking at the weld placment on the 2in2out pictures and see a pattern. It would be a good discusion as well. Jeff
Hi Jukka, You can shrink with a mig weld. It will be a very small area, but try turning down the wire speed slightly, and do a very short hot zap on the high spot, then file, sand, or grind it down. You will have shrunk. Much faster with a torch or shrinking disc, and the metal would be more workable after low temperature shrinking than with a weld shrink. John www.ghiaspecialties.com
Progress The front part that bolts to the running board I've tried a few different methods. This one seems to work the best. I made a paper pattern, and after I saw the amount of shrink involved I decided to slice a releif. The first couple I made in one peice shrinking and stretching. It was a bitch, and I had a few panels crack and split. Clamped and bent. The wide slot I cut in the panel fits up nice and welds up good. The slits on the side open way up though. I had to do some high fill gas welding. May look ugly, I know. It cleans up good though. I go over the welds with a die grinder set up with the cutoff wheels like Johnny. Then I go over it with a file and a da sander.
Mindover, thanks for the idea. I´ll have to try that. I have seen your DVD and it was very informative. I just have to watch it a couple of more times so I can remember all the new info. (new to me anyways) John Kelly, thanks for the response. I do realize that this would not be the best method and would make the metal harder to work with. But I got my answer.I have been aware of the shrinking disc for a some time but hadn´t realized that you could shrink the metal with it even if the surface didn´t have the high spots where the heat concentrates. Gotta get me one of them discs… Jukka
Hi Jeff, you have obviously struggled with this area. There are lots of ways this could be done but I think I would weld the flat part on after forming the rest. you might find it easier to make the reverse curve area as a separate part. You may find it best to weld the flat part on with mig - Mig is well suited to corner butt welds. I hope this helps, David
Thanks David, I've done it that way too and it worked but thinned the panel out because there is so much stretch. I started doing like this because it is quick. I have to admit I almost didn't post pictures because it is a little ugly, but I thought it may present an oppertunity to get new ideas. I need to turn the fender into Christmas $$$ so I'm going to run with what I have. I think I'll make a patch that looks like a Pringle potato chip and weld it in.
Jeff Yes sorry I did not mean for this wing, I know you said you intend to make several wings on those bucks - I was advising for future ones. David
Hi Jeff, Have you tried making that last piece from one piece of metal? I would roll that over my leg, and tuck shrink the curves, then stretch the corners surrounding the flat portion out into a shotbag. Flatten out the flat area by hammering over a steel or hardwood form. At least that's how I would first try to shape it. The Wray Schelin method of a flexible shape pattern would help show you exactly where and how much to stretch for the sharp areas surrounding the flat portion. John www.ghiaspecialties.com
John I've done it in one peice. It's a bitch. That slot I cut out has to shrink or stretch to make the shape. Even if you make the peice that the running board bolts to seperate, the edge of the reverse ends up paper thin. The buck is set up as a hammerform. This didn't work to bad doing it like this. The peice took me about 1 1/2 hours this way. This is a peice you can buy aftermarket. It resembles the original, sort of
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