Welding on trailer

[Margo]

Need to do a little welding to ramps on trailer that I use to haul tractor. Have to back it up to shop. Will it hurt truck or trailer to leave hooked up. TIA.

 

[Absent Minded Farmer]

I'd disconnect the truck to err on the safe side. The trailer should be ok, provided there isn't a battery on it to power something.

Mike

 

[Jim.ME]

Need to do a little welding to ramps on trailer that I use to haul tractor. Have to back it up to shop. Will it hurt truck or trailer to leave hooked up. TIA.

Disconnect the two would be the by the book recommendation. It really isn't hard to pull the plug and jack the trailer off the hitch.

In any case, the key is to keep the ground at the weld area, whether the truck is connected or not. If you were to ground to the truck and weld on the trailer you would be inviting trouble. If you ground right next to where you are welding there should not be a problem leaving it connected, if you don't want to unhook it. YMMV.

 

[BarnyardEngineering]

Maybe my understanding is wrong but I thought the concern was for the solid state electronic components not the battery. Since most trailers don't have solid state electronics on them, disconnecting the trailer battery doesn't really serve any purpose.

Really it only takes a few seconds to drop the jack and lift it off the ball. Even though the odds of causing a problem is slim, by disconnecting the trailer you reduce those odds to zero.

 

[chvet73]

It’s a simple decisio. Gamble on nothing wrong happening or disconnect. I’d disconnect.

 

[DoubleO7]

The only reason I might want to leave it connected to the truck would be if the trailer was likely to roll away if not connected.

In that case I would block the trailer tires then disconnect the trailer and just pull out from under the trailer a bit.

 

[old]

Need to do a little welding to ramps on trailer that I use to haul tractor. Have to back it up to shop. Will it hurt truck or trailer to leave hooked up. TIA.

I'd unhook the trailer and never look back. Some of the newer trucks etc. have computers that could be harmed and it is always better to be safe then sorry

 

[cjunrau]

Need to do a little welding to ramps on trailer that I use to haul tractor. Have to back it up to shop. Will it hurt truck or trailer to leave hooked up. TIA.

I never unhook. I weld up exhaust pipes on vehicles all the time. Keep ground close to where you weld and you should never have an issue. It’s kinda like telling someone that new vehicles should never be boosted. I’ve heard that so often by people who have never done it. Maybe I’m the lucky one and other people aren’t.

 

[old]

I never unhook. I weld up exhaust pipes on vehicles all the time. Keep ground close to where you weld and you should never have an issue. It’s kinda like telling someone that new vehicles should never be boosted. I’ve heard that so often by people who have never done it. Maybe I’m the lucky one and other people aren’t.

I've heard of a poor connection at the ground clamp causing a computer problem. I figure it this way if you disconnect the battery/truck then your sure if you don't while it may not hurt any thing but if it does it can be big $$$$$$$$$$$$$$$$$$$$$$$$$$$$

 

[old]

I never unhook. I weld up exhaust pipes on vehicles all the time. Keep ground close to where you weld and you should never have an issue. It’s kinda like telling someone that new vehicles should never be boosted. I’ve heard that so often by people who have never done it. Maybe I’m the lucky one and other people aren’t.

I've heard of a poor connection at the ground clamp causing a computer problem. I figure it this way if you disconnect the battery/truck then your sure if you don't while it may not hurt any thing but if it does it can be big $$$$$$$$$$$$$$$$$$$$$$$$$$$$

 

[rustred]

Your not too old to learn from actual welders advise.

 

[caterpillar guy]

I've never bothered to unhook even on the semi and never had a problem even welded up one of the differential cap that rusted through with no problem And it looks like I need to do something like that again. Don't want to have to pull the whole axle out and rest all the gears and bearings with new seals. So weld it up again. After all it's 25 years old next year. Not planning on getting another in my lifetime. The cap is on the back side welded on originally so would have to change the whole housing if not welded up.

 

[BarnyardEngineering]

It's not a matter of, if you don't do this something bad is guaranteed to happen.

The odds are heavily in your favor, so much so you could go through life ignoring the advice and never have a problem. Many things in life work that way. You can drink and never get liver disease. You can smoke and never get lung cancer. You can refuse to wear safety glasses and never get anything in your eyes...

It's a matter of a simple action reducing your odds of a problem from slim to NONE.

While it may never happen to you, it's going to happen to someone somewhere, and it's going to cost that unlucky person a heap of money to fix what got damaged.

 

[John T]

FWIW I for the record recommend you to electrically remove/disconnect a tow vehicle and its battery/electronics as well any trailer battery BEFORE welding. So simple and easy prevention could possibly prevent damage WHY NOT do it, even if there may not be any problem otherwise ??

Your choice to disconnect or not, none of ours, and sure there may be absolutely NO problem whatsoever if you choose not to.

John T

 

[Mark-Ia]

In my BIL muffler shop, they never unhook the battery or ground and never have a problem welding on a car.

 

[bc]

Who needs ramps if you have a front end loader. I drive the JD with the front tires within an inch of the back of the trailer. With a flat bucket down on the trailer I keep going down with the loader until the front wheels are above the trailer. Then curl the bucket making the tractor roll forward until the front wheels are on the trailer and lift the bucket. Tractor will be in neutral or you can slow ahead as you curl the bucket. The weight of the front of the tractor will push the back of the trailer far enough down that I can drive up to it and the back tires just bite and drive it on the trailer. The back of my trailer has round bar where the ramps attach to so the back tires aren't biting on anything sharp. Works for me. Might depend on how heavy or how big the tractor is probably as it probably wouldn't work for a small tractor.

 

[MARK ROBKE]

I welded things for years on semis and box trucks. The MAIN THING is to have a good, clean ground near where you're welding. You don't want an electrical component between the weld and its ground. Never unhooked a battery, but it won't hurt to unhook from the tow vehicle. Always err on the safe side. Mark.

 

[Margo]

Thanks for all the advice. Unhooked and completed job. Better safe than sorry.

 

[Hemmjo]

I find it is important to UNDERSTAND WHY you should do things a certain way, rather than just follow a simple rule. Sometimes the rule is simple, but it leads to miss understanding. There are many examples of simple rules being totally miss understood in reality. Wait an hour after eating to go swimming is one example. Where did that come from?

Electricity always takes the path of least resistance. If there are multiple paths, some may take the long way around. (this is why you might feel a tingle if you tough a defective electrical device) That is a law of physics. Take the example of welding on an exhaust system. If you hook the ground clamp to the frame, then weld on the exhaust the current has to pass through the frame to get to the exhaust. The exhaust is typically mounted in rubber. The best path from frame to exhaust may very well Oxygen Sensor, via the ECU. That is NOT a good situation. BUT, disconnecting the battery will NOT remedy that situation. This is why UNDERSTANDING is more important than blindly following a rule.

If you are welding on a trailer, even if it has a battery, and it is hitched to the truck with the wires still connected, the current is not going to travel from the trailer to the truck then back again. Assuming you have the ground connected to the trailer.

It is just good welding practice to keep the ground as close to the weld as reasonable, on the same piece you are welding on. Don't count on the little electrons finding there own path to the weld, YOU make sure they have the shortest path possible to do their magic. They are NOT going to go out on their own and get into places they should not be, unless you do not provide them a CLEAR path for them.

 

[John T]

Thanks for all the advice. Unhooked and completed job. Better safe than sorry.

Wise choice !!!!!!!!!!

John T