Welding: Damage to Electrics?

[Charlie_Iliff]

I am about to undertake some welding on my new Power Trac. MossRoad reminded me of the possibility of damage to the electrical system of the machine caused by welding to it.
In the past, I have welded on cars and tractors without experiencing a problem. I would appreciate hearing from anyone, however, who has experienced or observed damage to a part of the machine not being welded upon, and if any, how damage can best be protected against.

 

[Von]

Charlie,Disconnect the battery at the NEG. and keep the ground on your welder clamped close to the weld that you are making. IE: don't clamp to a wheel and be welding on the frame. You want to have the ground on the piece you are welding to, and not something bolted to it. Doing this you should have no problems.

 

[Charlie_Iliff]

Von:
Makes sense, and I'll do it that way. Do you know the actual mechanism by which damage may have been caused? I can understand if the ground is claimped so that current may have a parallel path through the alternator, for instance, but have you experienced or heard of induced current or some other phenomenon causing a problem somewhere when the ground is close to the work?
Thanks

 

[TonyC]

I apologize for stating the obvious but a gas welder is a safer route. No possibility of electrical damage using that!

 

[Von]

Charlie, I have never had problems with electric items and never have heard of any if the battery is disconnected. Have heard of bearing damage due to ground placement. Keep the ground close to your weld and you will be fine.

 

[whoodle]

Probably not applicable to your pt, but automatic transmission computers advise to disconnect wiring harness before welding. I would always disconnect sensitive stuff.

 

[MossRoad]

I can't gas weld on a vertical surface, due to my poor welding skills/w3tcompact/icons/shocked.gif.

 

[MossRoad]

I read through some of my old welding manuals and all it said to do was disconnect the battery and disconnect the alternator.

Of course, this was written before cars had computers, so it shows you how long ago I took welding classes /w3tcompact/icons/tongue.gif.

 

[Bird]

Charlie, you might want to read <A target="_blank" HREF=http://www.tractorbynet.com/cgi-bin/compact/showflat.pl?Cat=&Board=ag&Number=15702&page=&view=&sb=&o=&vc=1>this thread</A> from awhile back, and of course, there was another even older one on the same topic, but I can't find it.

 

[Charlie_Iliff]

Thanks all.
I'll disconnect the negative and cross my fingers. Certainly, I/m not worried about computer controls, and alternator diodes can be replaced if I fry some.

 

[RPM]

I don't know about the electrical systems, but I do remember getting a safety lecture about not welding cracked rims on construction vehicles while the tires were on and inflated. Apparently you get a very big bang - big enough that you can lose a limb! Not sure it would apply to compact tractors, but I wouldn't recommend anyone be the guinea pig. /w3tcompact/icons/eyes.gif

Just did a quick web search and found an interesting article <A target="_blank" HREF=http://www.ohscanada.com/virtual-issue/artucle/tires.html>here</A> ...

Patrick

 

[TonyC]

<font color=blue>I can't gas weld on a vertical surface, due to my poor welding skills</font color=blue>

Hehe...it's not that hard. Just do what I do...just flip 'er on her side!/w3tcompact/icons/smile.gif/w3tcompact/icons/smile.gif/w3tcompact/icons/smile.gif

 

[bgott]

I saw a guy weld the bearings to the crankshaft on a Peterbuilt one time by clamping the ground on the front bumper and then welding the mudflap brackets on. Does this count? Another thing, if you are welding a long way from the ground point, use AC. DC welding can cause a phenomenon known as " Arc Blow". Arc blow is when you're welding and the arc starts wandering all around the spot you want it. It about blew my mind the first time it happened to me, I figured I just about had this welding thing down pat when this s%$t starts happening! I was tacking plate on a steel hulled fishing boat about 30 feet from the welder so I doubt it will happen to you but I don't know how far away you have to be for it to happen. Something to keep in mind.

 

[Von]

Hehe...it's not that hard. Just do what I do...just flip 'er on her side!Tony, Don't laugh, thats just what we used to do when I had an Auto restoration shop. Here is a photo of a Jag XKE on the rotisserie all cleaned up and ready to be welded back together.

 

[MossRoad]

Bring that unit over to my house... but it will have to do end to end, as I want to weld on the rear surface/w3tcompact/icons/smile.gif

 

[TonyC]

LOL...Well Von, you're right. I was just making a joke but it appears to be a reality. Who da thunk it?!