Guest libbyde Posted February 27, 2008 Share Posted February 27, 2008 Hi, Just bought a 71 240z that needs a some floor pan work. I bought a MIG welder and am going to be working on it soon. I just need a couple safety questions answered : 1. Must I take the gas tank out of the car to MIG weld the floors? I know to take the battery out. Anything else I should remove? The interior is completely gutted of course but the gas tank and tires are all on. 2. When the ground cable is attached to the floor of the car is it ok to crouch in the car while welding the floor? Or will I get shocked? Sorry for the dumb questions but safety first and I have never mig welded before. Thanks, Ron Quote Link to comment Share on other sites More sharing options...
jojothemonkey Posted February 27, 2008 Share Posted February 27, 2008 You should be fine with the gas tank in the car. If you really worried about it you can always drain it. There should be a plug on the underside. And no you dont have to worry about being shocked while welding. Make sure you measure and trial fit as many times as you can. Also do as much practice welds as you can. Good luck! Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted February 27, 2008 Share Posted February 27, 2008 You should be fine with the gas tank in the car. If you really worried about it you can always drain it. There should be a plug on the underside. You can weld on the car with the gas tank in it. I highly recommend disconnecting the fuel lines that go through the transmission though and even removing them. The last thing you want is a flame thrower under your car. And no you dont have to worry about being shocked while welding. Not true. I have been shocked through my leathers before while TIG welding. You have to watch where your ground cable is hooked up or you can possibly get shocked. Be sure to keep it as close as possible to the area that you are welding. (I do have a college degree in welding and joining technology...) You can never be too safe. OTM Quote Link to comment Share on other sites More sharing options...
johnc Posted February 27, 2008 Share Posted February 27, 2008 Welding On Cars Safety 1. A recently drained fuel tank is more dangerous then a full fuel tank because of the trapped fumes. If you're replacing or welding on the floor pans its probably a good idea to pull the fuel tank from the car. You might as well check that are of the car for rust and possible repair while you've got the welder out.. 2. If you're welding near the transmission tunnel, pull the fuel and brake lines (brake fluid burns very well). 3. Undercoating, dirt, rubber, and grease will catch fire and burn. The same stuff will also smolder for a long time and then catch fire. Soak a bunch of rags in water and use them to extinguish any of these fires 4. Keep a 10lb. fire extinghisher very close to your work area. Check for fire every couple minutes. Keep all flammables, solvent, rags, gas cans, etc. at least 10' away from the car. 5. Wear long a long sleeve cotton shirt, leather gloves, a cotton baseball cap or welding doo rag, heavy shoes, and a full face welding helmet. 6. Keep your face out of the welding fumes. Don't breath the stuff. 7. Keep your clothes, hands, and feet dry and free of solvents or hydrocarbons. 8. Make sure a friend or family member knows what you're doing and checks on you periodically. If you knock yourself out, the sooner someone finds you the better. 9. When you're done working on the car, hang around for about 15 minutes to make sure something that is smoldering doesn't light up. 10. Remove the carpet and seats from the car if you're welding on the floor pans. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 27, 2008 Share Posted February 27, 2008 I caught my wiring harness on fire welding underneath the car. It runs through the rocker panel, so just be aware of it when you're welding near the rockers. Quote Link to comment Share on other sites More sharing options...
Guest libbyde Posted February 27, 2008 Share Posted February 27, 2008 Thanks for all the info! Quote Link to comment Share on other sites More sharing options...
letitsnow Posted February 28, 2008 Share Posted February 28, 2008 If you don't clean the underside of the area that you're welding the undercoating will make a really thick nasty smoke and fill your garage completely within minutes, trust me. Get a fan or something to ventilate the area. The light from welding can actually give you a sunburn so cover up if you're going to be welding for any period of time. Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted February 28, 2008 Share Posted February 28, 2008 The light from welding can actually give you a sunburn so cover up if you're going to be welding for any period of time. I learned this one the hard way. One day at welding school I went for a water break and came back to start MIG welding and completely forgot my leather jacket. After a minute or so I realized that my arms were feeling warm. Lets just say I had a redneck T-shirt sleeve tan line for 2 months...LOL It went much deeper than any regular sunburn. Quote Link to comment Share on other sites More sharing options...
wheelman Posted February 28, 2008 Share Posted February 28, 2008 If you don't clean the underside of the area that you're welding the undercoating will make a really thick nasty smoke and fill your garage completely within minutes, trust me. Get a fan or something to ventilate the area. An even better reason to clean all the undercoat off is to get decent welds. Welding with the undercoat still there will cause the welds to be contaminated. It will also be a real pain to try welding the thin sheet if the surface you're trying to join to is dirty, it'll pop and burn through much easier. Wheelman Quote Link to comment Share on other sites More sharing options...
DemonZ Posted February 28, 2008 Share Posted February 28, 2008 While MIG welding, what I thought was a stuck trigger, resulted in a big scare. I scrambled fast to turn off the machine while long looms of hot wire some 7ft long was ejecting uncontrollably until I pulled the plug on the welder. This could have punctured a tank or something explosive nearby. Luckily it didn't and I was not in a confined area and could make it to the welder relatively quickly. This happened a couple more times after 10 min of 180 Amp welding. Turns out my "connector" relay was sticking and was worn (moderate/heavy hobbyist use). Now I still feel slightly uneasy about any welding where I am confined, and can't rush out in a hurry. My welder works fine with a new connector now, but whenever I weld these days I make sure I have a fast escape route and that I can pull the plug quickly. Quote Link to comment Share on other sites More sharing options...
johnc Posted February 28, 2008 Share Posted February 28, 2008 While MIG welding, what I thought was a stuck trigger, resulted in a big scare. I scrambled fast to turn off the machine while long looms of hot wire some 7ft long was ejecting uncontrollably until I pulled the plug on the welder. Next time just jamb the nozzle against what your welding and the wire will bird's nest in the machine giving you time to go back and shut it off or the machine's circuit breaker will trip stopping the feed. Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted February 28, 2008 Share Posted February 28, 2008 Good tip. I would have screamed like a little girl and ran from the garage. Quote Link to comment Share on other sites More sharing options...
DemonZ Posted February 29, 2008 Share Posted February 29, 2008 Next time just jamb the nozzle against what your welding and the wire will bird's nest in the machine giving you time to go back and shut it off or the machine's circuit breaker will trip stopping the feed. Ah... nice. That woulda saved me some white hairs! Great tip. Quote Link to comment Share on other sites More sharing options...
Warren Posted February 29, 2008 Share Posted February 29, 2008 OH yeah, you've got a better chance of burning yourself than you do shocking yourself while welding. Don't test the joint to see if it's still hot or wipe away anything that you think might come off until LONG after the weld has cooled. And for God's sake, don't weld near brake parts cleaner...that stuff is HIGHLY flammable and will explode violently if the can is arced to. Just common sense. Quote Link to comment Share on other sites More sharing options...
johnc Posted February 29, 2008 Share Posted February 29, 2008 Here's a little story... A customer of mine raced a very early Honda S2000. Those early cars had a tendency to tear out the upper front control arm mounts. My customer happened to work at Honda and some of the technical guys wanted to see how this could be repaired because the follks in Japan said it couldn't be fixed. Well, I (and every S2K racer and fabricator) had already figured out a simple fix. My customer showed up with a couple Honda techs and some obvious Big Wig in a suit wearing some really nice shoes with tassels on them (must have been a marketing guy). While welding on the car a couple Acetone soaked rags I had lying nearby caught fire. Not a big deal, I was just going to let them burn in the middle of an empty concrete floor because I had just a couple more little welds to do and I was already in position. Well, Mr. Big Wig decides to be a fireman. He walks over and stops on the rags with his nice, tasseled leather loafer. Since the rags had a flaming liquid on then, the flaming Acetone immediately transferred to his shoe and now he's got a hot foot. Mr. Big Wig stares at it for a second and then starts stomping the shoe on the ground, faster and faster. I grab a wet towel I had next to me and threw it on his flaming shoe. That put the hot foot out, but his tassels were burned down to nubs. I told him that I was revoking his Junior Fireman's badge. I don't think he appreciated it because he walked out of the shop and sat in his Acura for the rest of the visit. Quote Link to comment Share on other sites More sharing options...
evtech Posted March 1, 2008 Share Posted March 1, 2008 Hi Found this web site sometime back and even as a fitter some of the minor points are good to refresh the old grey matter. http://www.mig-welding.co.uk/ Only burnt one car out:oops:, but I was gas welding that at the time, it was after this I bough the mig, Oh and a 2 gallon foam extinguisher:D Regards Nigel Quote Link to comment Share on other sites More sharing options...
Canadianz Posted March 1, 2008 Share Posted March 1, 2008 I think the above points are really valid as far as safety when mig welding is concerned. Basically there are only a couple bad things that can happen while welding, either you burn yourself, which is easy with all the under coating and dirt associated with welding on a Z or you can start a fire. This is solved easily by making sure you are welding onto clean bare metal which is both clean of grease and paint. By getting rid of the contaminants you will have a much better weld, less smoke and less chance of a fire. As a side note, make sure you have a really good ground too, it will help with your welds and make sure that the outlet or extension that you use is rated to handle the current you welder needs. If its not your going to flip breakers and have bad welds. I learned this year how to weld on my Z so my points are totally based on my only experience I have, hope they help. Wearing a good respirator and an auto darkening mask will really help out alot, from a safety and comfort standpoint. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted March 3, 2008 Share Posted March 3, 2008 " I would have screamed like a little girl and ran from the garage." THANKS I NEEDED THAT LAUGH, the picture in my mind was funny as %^&* " This happened a couple more times after 10 min of 180 Amp welding. Turns out my "connector" relay was sticking and was worn (moderate/heavy hobbyist use)" WHAT MODEL AND BRAND?? Quote Link to comment Share on other sites More sharing options...
Guest libbyde Posted March 3, 2008 Share Posted March 3, 2008 Thank you all for the great info!!!!! I am going to start welding soon hopefully, I just have to fix my roomates damn RX-7 first . I will let you know how it goes. Quote Link to comment Share on other sites More sharing options...
letitsnow Posted March 5, 2008 Share Posted March 5, 2008 Thank you all for the great info!!!!! I am going to start welding soon hopefully, I just have to fix my roomates damn RX-7 first . I will let you know how it goes. The easiest way to fix an RX7 is with an LS1. Good luck! Quote Link to comment Share on other sites More sharing options...
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