So, after watching the Bosses car hauler bil weld on his trailer with his truck running, my co worker wondered about the danger of welding things on the back of his mechanics truck, 06 F550, while hanging something from crane or holding in the vice. My general rule is get the ground very close to what you are welding? Disconnecting batteries on the service rig to weld things would be a PITA. Thoughts? Thanks Russ
I've been taught to keep your ground lead as close as possible to where you are welding. I haven't screwed anything up yet and I been doing this for over 15 years. But if you aren't sure or it just makes you feel comfortable then disconnect the batteries. Better safe than sorry.
That's a key point . I generally grind of a fresh clean spot on the subject to be welded , clamp a vice grip to it and drop the ground clamp on the vice grip . Electricity will take the path of least resistance . I try to give it a good open road when welding .
I agree with the others, ground clamp where you are welding. I've been doing it that way for well over 40 years and I've never fried anything other than the piece I'm welding. If the piece/spot your welding doesn't have a good place to clamp take a sacrifice bolt, clamp the ground clamp on it and tack weld the bolt to the work piece. Knock the bolt off when you're done and grind the tack weld off.
The danger is if you are welding two pieces that broke, on some truck or machine, the start of the arc may go to the other piece from the one you have the ground clamp on and take a circuitous route to get back to the clamp. So just bear in mind what will happen if the arc goes somewhere you don't want it to when you are first starting the weld. Once the pieces are bonded it is no longer any worry.
I totally agree Birken Vogt, and that would at the very least be an inexperienced welder. After all, on broken pieces with a gap, an experienced welder would light up his torch on the piece that has the ground attached and move the arc to the adjacent broken part to mate it with the part that's conducting the current to make the weld. But I realize there's no shortage of idiots on our planet as well.
I notice the FM radio in my service trucks never works very long. I think it’s from welding on the bench and vice.
Great point ! Light the rod first on the grounded work . Not on a vehicle but had some of the same concerns when we tied in some valves at the school . Not allot of room to work and phone & computer wiring everywhere . All went well & Miss Johnson was able to teach " Home Economics " on Monday . LOL ! HeavyEquipmentForums
fwiw if i have to weld on anything that has an ecm the batteries get disconnected. only takes a little extra time
I agree you "should" light the rod on the grounded part but it only takes a slip of the hand. Or even the split second before a puddle is formed, the arc can be wavering back and forth between parts. I have been known to disconnect ECM connectors completely. Disconnecting batteries may not prevent welder current trying to flow on a sensor wire or some such nonsense.
You are so right. In simply disconnecting batteries, just how is that totally insulating the ECM? And to access the ECM on some machines to disconnect all the mod connectors, well that can be a challenge in itself. I totally agree and get where your coming from, but time is money, for that reason alone I'm gonna lean on my weld experience to not burn the house down and get it done with no side effects, I've got other stuff waiting in line.
I have a former plow truck and it has warning stickers to disconnect BOTH battery cables before doing any welding due to sensitive electronics. I worked in a shop building winch decks and they would disconnect the batteries and unplug the harness for the ECM. I think it voided the warranty on new trucks if you didn't. On most older equipment it's not too bad but disconnecting the neg. battery cable at least gives you piece of mind and doesn't take long.
Pete/KW body builders manual instructs to unhook All ECMs and battery before welding on the chassis or attached body. Maybe you guys can dream up a way to insult the top work plate of the bumper-workbench? Not practical to unhook battery cable and ECMs 2012 M106: Has heavy battery cable connecting both frame rails; came that way from Penseke Leasing
Watched an old welder, once. He hadda 6' or so long jumper cable, with a ground clamp, on each end. ground a patch on each side of the parts he wanted to weld together, hooked the jumper to each side, then grounded the welder, to same patch as the the jumper...
Have been using this for a few years now on the 12V systems...anyone else tried em out? Regards, Bob
I have used them on 12&24 volt. I don't know if they worked or not. I just used them to make the boss happy. Everyone got one after a mechanic hooked up his welder to jump start a motor grader and left running for half a day. Which that did fry every ecm on the machine. I'm not even sure if he properly set the welder up for 24 volt DC or not. But leaving one hooked up for several hours can't be good. After that we were not even allowed to jump start with our welders at all. I did anyway but I don't leave it hooked up all day and I know how to set it up for 24 volt DC. People can complain about bad mechanics all they want but I love them because they make me look like a genius
Our weld shop at a major demo company used those when repairing machines they never cooked any electronics. I never cooked any electronics yet welding on equipment or class 8 trucks , when i worked at an international dealer when they still had ih trainers/teachers he said the likely hood of cooking an ecm due to not unhooking the batteries was slim to non , he did warn of welding and geounding properly near the engine as he had to diagnose one that was eating main bearing and found the crank got magnatized do to somone grounding the welder in a bad spot
I had a welding deck someone else made that had cable reels under the deck. He used backlite pucks to mount the reels and put rubber hose around the bolts holding them on to insulate them from each other. I think hockey pucks under the deck and for washers for the nut would work. The large bolts could have thick rubber hose around them.