Owen Posted February 18, 2000 Share Posted February 18, 2000 I am seriously looking into getting a MIG welder in the near future, a flux/gas combo one with settings for spot and seam welding too. My question is, where are the most important places to do this? Spot where and seam where? I want to do the subframe connectors too but after I get new floors. Owen ------------------ http://www.homestead.com/s30z/index.html Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted February 18, 2000 Share Posted February 18, 2000 You can't go wrong with a Mig welder! You definitely need one when building a car.Do get one that uses gas, it makes a stronger and cleaner weld. As for spot and seam settings, there isn't any. A spot weld is when you weld a series of small spots just to hold the piece. Then you seam weld between the spot welds. Your going to have to do a lot of practising before you attack your car. I think some welders have a stitch weld setting, but you can do that on your own.All it is, is spot welds very close together. Quote Link to comment Share on other sites More sharing options...
pparaska Posted February 18, 2000 Share Posted February 18, 2000 There are special tips for doing "spot" welds through two pieces of metal, but I've had little luck with them. Basically it is a gas nozzle that has prongs that extend out that you put against the metal, turn down the wire speed, and just hold the trigger while the area gets hot. Didn't work well for me. I had to drill a hole in the top piece of metal that I was trying to join to the one under it to get it to work. At this point it just becomes a "plug" welding operation, which you can do without the special gas nozzle. The problem with plug welding is you have to predrill. Definitely forget about the flux core wire and just get a gas setup. If you plan on doing aluminum, it's best to get a gun with a feed reel on it. I don't have that setup but would love it. Be warned that the cheaper 110V welders have low duty cycle and you end up waiting for them to recover after welding a while, or they sputter like mad. Do it right and get a good 220V unit if you can afford it, and run a 220V line to your work area if you don't have one. Wish I had just gotten a 220V version instead. Once you have a Mig, you'll wonder how you got along without it! And they are very easy to learn to use - even teaching yourself. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@tidalwave.net">pparaska@tidalwave.net - Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 19, 2000 Share Posted February 19, 2000 I don't have any experience with a 220V MIG welder but I have welded with 120V MIG's for probably 8 years or so. I presently am running a Lincoln 100A unit with an 80% duty cycle. I have welded up to 3/8" steel with multiple passes with this welder without any complaints. The most recent application of my welder was securing the main loading mounts for an 8' snow plow on the front of a truck. I beveled all welding surfaces 1/8" and then welded around the perimeter of mounts w/ 3 seperate passes. I didn't experience any sputtering and the welds have held through 4 recent snow storms where the snow was wet and between 8-10" deep. I don't think it matters as much on the voltage...but get a welder that has a good duty cycle and is a good brand name. Hobart, Lincoln, Century, Miller...all good brands that will serve you well. SpencZ Quote Link to comment Share on other sites More sharing options...
pparaska Posted February 19, 2000 Share Posted February 19, 2000 Spencz, I wasn't saying all 110V Migs were bad, but most of the 220V ones are decent. I agree that you should only buy one of the higher end brands either way, to get a decent machine. Usually, the 220V units have better control of the wire speed and better duty cycle. But the good 110V ones do also. Quote Link to comment Share on other sites More sharing options...
SpeedRacer Posted February 19, 2000 Share Posted February 19, 2000 Owen, What we did with mine that worked great. We dropped the front suspension and "boxed" in the sub-frame. We used 1/16" thick 2" X 2.75" angle iron and boxed from the inside of the fender across the sub-frame and down. Then we mig welded another 3" strip of 1/16" steel on the bottom of the sub-frame all the way from the radiator support into the floor pan. The edge was welded to the previous angle iron to form a C section. You have to drop the suspension for the bottom piece because you will have to put a couple of holes in it (susp, sway bar, etc). Presto! no more flexible flyer! Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted February 20, 2000 Share Posted February 20, 2000 I have a lincoln 110v also, it is a very reliable machine. Unfortunately I have flux core, its welds nicely, but if you stop you have to chip off slag. I never welded before and went right to it. I welded several pieces and cut across the weld to see penitration till I got it right. I haven't ever welded anything as thin as the frame on the z cars, but its next on my agenda, after I convert to mig. I hear thin metals are much harder than thicker ones. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 20, 2000 Share Posted February 20, 2000 I've welded down to 20ga plate steel with just flux core. It is hard but it can be done. MIG is much better with thin stuff and isn't difficult right down to 22ga. 24 ga can be welded but preventing serious burn through is challenging. spencZ Quote Link to comment Share on other sites More sharing options...
Mikelly Posted February 22, 2000 Share Posted February 22, 2000 Being a certified welder, I'll state this as best I can so we all understand the differences in 220 & 110. There is nothing wrong with lower voltage welders. However, one big issue is fine tuning the unit to provide a more consistant and stable heat range. Because I was over seas at the time my cars frame and floor pans were done, I'm skeptical about the welds and will probably re-do them in the not so distant future. They look like the product of a poor duty cycle 120 welder in the hands of someone who didn't know how to get the most out of the unit. The higher voltage welders allow for greater lengths of duty cycle with less interuption of service, providing a more uniform and consistant weld, less fluctuation in heat. Now, there is nothing wrong with using a 120 welder as long as you know that you will need to take shorter and more multiple passes, and you will probably have heat consistancy problems which lead to holes burned in sheet metal. Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
Mikelly Posted February 22, 2000 Share Posted February 22, 2000 Back to Owen's original request... I'd focus on the TC mount boxes, the seems of the strut towers, the frame rail transition from the rail to the front Sub frame, replacing the frame rail under the car with one that runs from the front frame to the rear frame, and seem weld the rocker area beneath the car. Also, as others have found, check those floor pans. If you find any rust at all, replace them, because more rust is probably trapped under the rust proofing and sound deadening agents. Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
Owen Posted February 22, 2000 Author Share Posted February 22, 2000 Thanks Mike and everyone else. I understand about the voltages and the duty cycles, but the lack of money I have is the biggest deciding facotr, I will try and go for a well known brand name though. Mike, what are the TC mounts you mentioned? I won't even touch the floors until I get new ones, I also need a new rear hatch lock plate. $100 bucks from Nissan! I wonder if I can make my own... Owen ------------------ http://www.homestead.com/s30z/index.html Quote Link to comment Share on other sites More sharing options...
Mikelly Posted February 22, 2000 Share Posted February 22, 2000 The Tension Compression rod runs aft of the lower control arm and is attached to the lower control arm with two 12mm bolts. The TC rod runs back to the frame rail and has a flimsy box shielding it. This rod has a bushing on the end with two flat washers. I would weld in new TC mounting areas with heavier metal or beef up the mount itself. The TC rod helps with deflection in the front strut. This helps each wheel track true with less individual caster, camber, and toe change. Critical to any daily driver or road racer! Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
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