Any precautions-electrical system-when welding on tractor?

wisconsitom · Jan 21, 2023

Hey all, we're going to weld some hooks onto a 3-pt. skidding winch that lives on the rear end of my tractor. This amounts to a few tacks really. Question is, should one disconnect the battery or anything when welding on what amounts to a part of the tractor, given it's all continuous from an electrical standpoint.

Or am I overthinking this, like I usually do?

rangerfredbob · Jan 21, 2023

For the most part using a DC welder (the welding current itself, not what the welder is plugged into) and having the welder ground as close to the weld as possible there is little chance of an issue, If using an AC welder doing similar should be fine but if the tractor engine has a computer it really would be safer to disconnect the battery...

wisconsitom · Jan 21, 2023

Thank you sir. This is a simple machine, a bobcat ct2025. No computer.

The welder is my son's Hobart tabletop mig, I know not the AC/DC, but can check that.

scootr · Jan 21, 2023

The welder current flows from the working tip to the ground clamp. No worries really. Make sure you clean the clamp contact area and keep it reasonably close to the work area.

wisconsitom · Jan 21, 2023

Thanks guys.

mikester · Jan 21, 2023

scootr said:
The welder current flows from the working tip to the ground clamp. No worries really. Make sure you clean the clamp contact area and keep it reasonably close to the work area.

I have a magnetized watch for sale. Keeps perfect time twice a day.

Welding can induce currents. Stray EMF starting and stopping arcs can be a bother for electronics. The safest bet is to disconnect the battery before welding but I don't always follow my own advice.

scootr · Jan 21, 2023

mikester said:
I have a magnetized watch for sale. Keeps perfect time twice a day.

Welding can induce currents. Stray EMF starting and stopping arcs can be a bother for electronics. The safest bet is to disconnect the battery before welding but I don't always follow my own advice.

Okay sure. But I probably did that once in 30 years and never had a problem then or the other 999 times I didn't disconnect. Of course I could just have dumb luck

Eagle1 · Jan 21, 2023

If you worry about EMF what good does disconnecting the battery do? You still have all the frame grounds (connected to your welder ground) and the current comes from the EMF not the battery. I agree that arcs could cause a problem by inducing higher voltage or current that the electronics can handle but that could still happen with the battery disconnected.
Not an expert and willing to learn.

sea2summit · Jan 21, 2023

scootr said:
Okay sure. But I probably did that once in 30 years and never had a problem the other 999 times. Of course I could just have dumb luck

90% of the time, I'm right every time.

LouNY · Jan 21, 2023

I try not to weld on connected electrical systems. I usually try and pull both battery leads off.
There have been a few times when I didn't with no adverse effects.
My bigger concern is welding across bearing or joint surfaces I try and keep my ground on the same piece that I'm welding to or on.
Often if I can I'll use the ground clamp to hold the piece that I'm going to weld onto the unit.

duffer · Jan 21, 2023

My logic says why take a chance. Disconnect both battery terminals, turn on your lights to deplete any current in the system, and you shouldn't have any problems. Fuses, or otherwise.

scootr · Jan 21, 2023

I have welded on every tractor I've owned without disconnecting the battery. I'm not telling you what you should do.
I'm just stating my experience.

5030 · Jan 21, 2023

Shortest path (stinger and ground close togethe)r and remove the battery cables.

wisconsitom · Jan 21, 2023

I reckon all things considered, we'll just disconnect the battery, simple matter that it is. FWIW, this particular job will consist of tacking the thin connector strap on u-bolts to top surface of Norse 250 skidding winch safety cage. I like the idea of using grounding clamp to hold this, or these-we might do more than one-in place while welding on.

hosspuller · Jan 21, 2023

LouNY has already mentioned ... beware of the welding current passing through bearings or pivots. You don't want a spot weld in any of them.

2manyrocks · Jan 21, 2023

Don't want welding spatter to burn a hole in a hydraulic hose, either.

strantor · Jan 21, 2023

If your tractor has a computer then it would be a good idea to disconnect it. I don't think it would hurt to disconnect the battery too, but neither do I understand how it could help. Is it to prevent damage to the battery itself? If so, it's worth pointing out that the battery is the most robust electrical component on the machine; even more stout than the wires that connect to it. Or are we thinking that the battery completes a circuit, so removing it is like opening a disconnect and preventing current from flowing in any circuit?

There are only two ways I can conceive that welding could damage electronics:

1. By raising the electrical potential of one ground higher than that of another ground, causing current to flow through electrical circuits in ways that it isn't intended to flow. And I think that would happen whether or not the battery was connected. The best way to prevent that is to place your ground clamp as close as possible to the area being welded.

2. By inducing high frequency EMI into wiring harnesses. This also is possible with or without the battery connected. The best way to prevent this is to keep ground lead and welding lead as far as possible from any machine wiring, and if you must cross a wiring harness with a welding lead, do it at 90 degrees, never running alongside a harness.

JJT · Jan 21, 2023

Why not take the winch off, weld your hooks and remount the winch? For me, that's far easier than screwing around with the battery and worrying about what if's.

ROUSTABOUT · Jan 21, 2023

wisconsitom said:
Hey all, we're going to weld some hooks onto a 3-pt. skidding winch that lives on the rear end of my tractor. This amounts to a few tacks really. Question is, should one disconnect the battery or anything when welding on what amounts to a part of the tractor, given it's all continuous from an electrical standpoint.

Or am I overthinking this, like I usually do?

Mainly be sure you are grounded to and welding on the same piece of metal.