GTPVETTE Posted July 21, 2006 Share Posted July 21, 2006 Hey Guys,,, We'll be doing a bit of mig welding on a buddies Z. I know doing a bunch of small welds,,, stiches, will help keep the panel from distorting but I have a question. Can we cool the panel with water or a wet rag to help speed the cool off process,,, or will it just make it worse??? Many Thanks! Fred Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted July 21, 2006 Share Posted July 21, 2006 Water on a rag will "quench" the metal rapidly but will also change its composistion. It will cause the metal at the weld site to become brittle which will invite cracks and can even worsen the warpage. Mig welding is heat at a very localized area. If you are careful and ensure that you tack the part on its periphery first before continuing. Dont overdo it. You will be fine. Quote Link to comment Share on other sites More sharing options...
johnc Posted July 21, 2006 Share Posted July 21, 2006 Why do you need to speed up the cool down process? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 21, 2006 Share Posted July 21, 2006 I can speak from limited experience. He might be trying to cool down the area to minimize the warpage so that he can move along faster. I have stitch welded my entire chassis and also done a few body repairs and started to shaved the marker lights and the gas door. When I stitch welded the chassis, I had a long seam to work on, so I'd just start at one end, then jump to the other, then back, etc and nothing got overly hot. When I did my dogleg repair I didn't stitch weld. I did 1000 little spot welds right next to each other until the whole seam was covered. When I did my marker lights I got impatient and tried to stitch them. This was a bad idea. I did the marker in maybe 15 welds. Warped the crap out of the 1/4 panel. If it's bodywork do the 1000 spotwelds. If its stitching a large area where you can spread the heat around, go for it. If you're trying to stitch in a very small area, don't stitch. Spot weld, and just bring a beer or a coke or something and try to relax and let it cool down so that you don't warp it like I did. Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted July 21, 2006 Share Posted July 21, 2006 Mr.Mortensen (QUOTE): If it's bodywork do the 1000 spotwelds. If its stitching a large area where you can spread the heat around, go for it. If you're trying to stitch in a very small area, don't stitch. Spot weld, and just bring a beer or a coke or something and try to relax and let it cool down so that you don't warp it like I did. When you say "spotwelds" do you mean to actually use a spotwelder or do you mean "1000 tack welds" placed close together? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 21, 2006 Share Posted July 21, 2006 See how much experience I have??? Tack welds is what I meant to say. Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted July 21, 2006 Share Posted July 21, 2006 Whew! I feel better now. Thought I was going to have to inspect all of my structural repairs!! Ha! Quote Link to comment Share on other sites More sharing options...
BlackBeaut Posted July 21, 2006 Share Posted July 21, 2006 Anybody have any experience with this type of stuff: http://www.frost.co.uk/item_Detail.asp?productID=8822 Cold front is a harmless, odourless, non-toxic putty that stops heat travelling through metal while welding, brazing, soldering etc., saving you time in two ways. Firstly, it concentrates the heat in your working area, saving warm up time, and secondly, it protects surrounding glass, rubber, vinyl and plastic from heat damage, making it unnecessary to dismantle before welding. It also prevents warpage when applying heat to areas of thin gauge metal. Works like magic. If it does work I can probably see it being more beneficial when oxy/acetylene welding and that warps the hell out of thin metal. Cheers, Rob Quote Link to comment Share on other sites More sharing options...
bjhines Posted July 21, 2006 Share Posted July 21, 2006 I warped the passenger side firewall slightly stiching with MIG... There is soo much going on there that it just got too hot, too many times, in too many different areas... before it got out of hand I stiched 2 u channels to the passenger side firewall to hold its overall shape... The drivers side already has a doubler plate to mount the pedal box... other wise I have not ahd any trouble.. I have tried a combination of spot welds and stich welding... they are both getting similar results... never go right along in a line.. I tack a few places along the length of a panel... then I fill in by skipping around... and I tend to stop after a few stiches on one panel and move on to another area while that cools down... notice the warpage has concentrated at the hole for the wire harness... frackin blowouts in the thin stuff are what's pissing me off.. they make it ugly as hell... I really had a hard time working in this area... Quote Link to comment Share on other sites More sharing options...
DemonZ Posted July 22, 2006 Share Posted July 22, 2006 that's got to be worth ten 2" holes right there. Quote Link to comment Share on other sites More sharing options...
GTPVETTE Posted July 22, 2006 Author Share Posted July 22, 2006 Hey Guys,,, Thanks for your thoughts,,, looks like 1000 tacks may be the way to go. The project is to put a flange on the top of the rear fender to attach flares to,,,, not to mention a couple of doglegs. As it isn;t my car I'd hate to warp the rear quarter too bad. The origional thought with the water was to help move things along as I know the cool down can take a while. Between the four area I guess we have enough to move between. Thanks again,,,, I'll post some pics in a couple of weeks,,,, as I'm goin on vacation!!!!! Quote Link to comment Share on other sites More sharing options...
mtcookson Posted July 24, 2006 Share Posted July 24, 2006 I can speak from limited experience. He might be trying to cool down the area to minimize the warpage so that he can move along faster. I have stitch welded my entire chassis and also done a few body repairs and started to shaved the marker lights and the gas door. When I stitch welded the chassis' date=' I had a long seam to work on, so I'd just start at one end, then jump to the other, then back, etc and nothing got overly hot. When I did my dogleg repair I didn't stitch weld. I did 1000 little spot welds right next to each other until the whole seam was covered. When I did my marker lights I got impatient and tried to stitch them. This was a bad idea. I did the marker in maybe 15 welds. Warped the crap out of the 1/4 panel. If it's bodywork do the 1000 spotwelds. If its stitching a large area where you can spread the heat around, go for it. If you're trying to stitch in a very small area, don't stitch. Spot weld, and just bring a beer or a coke or something and try to relax and let it cool down so that you don't warp it like I did.[/quote'] So, if say you were welding on the front end of the car (basically a front clip) you would recommend the tack welding? I have to do that very thing and after finding the whole car is basically glued together I'd like to tack weld a lot of the chassis pieces together to see if it might make for a more rigid chassis. Either way though, I still need to put a partial front clip on the car and am trying to find the best route for welding it on. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 24, 2006 Share Posted July 24, 2006 No, definitely do not tack weld the frame together. If you replace the front you're probably going to have upper and lower frame rails and fenderwells to weld together. I'd cut them in a Z pattern to get the most surface area to weld, then once the rails were welded together I'd grind it down and put a big piece of 1/8" plate over the joint and weld it all the way around the perimeter. The fenderwell I'd stitch around until you had the full seam welded. The tack welding is just for putting a small patch panel in. The stitch welding is for strengthening the frame rail at the seam, not splicing a rail in the middle. All that said, I've never done that type of job, so I'm just telling you what I would think would be the right way, you might get a more informed opinion on that by asking someone more knowledgeable. Quote Link to comment Share on other sites More sharing options...
mtcookson Posted July 24, 2006 Share Posted July 24, 2006 Ahh, ok. Luckily its not really a stressed part of the car. Its forward of the strut tower and such so is really only holding the radiator and headlights on the car and such. Of course, I have to get it perfectly straight but the way I'm thinking of doing it should make it hard not to be straight. I just want to be sure I weld it correctly. What you said definitely makes sense so I'll definitely keep that in mind. I'll be doing a lot of test welding before actually welding to the car just to make sure I get the welds done right. Thanks for the info! Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 24, 2006 Share Posted July 24, 2006 I'm still not buying the "everything forward of the strut towers is just dead weight" argument. This may be true if you have a serious cage/strut tower bar setup, but if this is just a regular old Z you're using everything up to and including the core support. Is your splice forward of the sway bar mounts? That IMO is the end of the really stressed area of the frame if you have the aforementioned serious cage and strut tower bar. Quote Link to comment Share on other sites More sharing options...
mtcookson Posted July 25, 2006 Share Posted July 25, 2006 Its in a Z32. The damage is actually right forward of the sway bar mounts. I'm pretty sure its also forward of the tension bar mount as well. Most of the damage was to the radiator support and just a little bit to the frame, but enough so that it bent a little bit. Quote Link to comment Share on other sites More sharing options...
cheftrd Posted July 25, 2006 Share Posted July 25, 2006 See how much experience I have??? Tack welds is what I meant to say. You were correct the first time. Spot welds can be made with any welder, but most people associate them with resistance welds. Spot welds are permanent and structural. Tac welds are like spot welds, but meant to hold something in place temporarily. Miller welding has a huge library available free to download, with almost anything you want to know about welding. http://www.millerwelds.com/education/library.html Quote Link to comment Share on other sites More sharing options...
zed240au Posted July 26, 2006 Share Posted July 26, 2006 my experience with welding body panels was to soak rags in water and place them around area your welding keep the smallest possible area affected by the weld to reduce warpage As for sitching the chasis for strength well i was young and stupid so i soild welded every seam in my zed been told ill never repair it should i have a accident but guess it should never flex either mick Quote Link to comment Share on other sites More sharing options...
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