Welding and insulating a lift hook, or vehicle

[Glenn]

Let us say you are working on large project that requires a crane, hoist, jib crane, engine hoist etc to lift, turn, or reposition the project. The load is lowered to the ground to take the weight off the project, but is still being held upright into an upright position by the crane. Throw in some additional supports to keep it upright, just for the sake of safety.

If you now weld on this project, would a less than perfect ground clamp connection allow the welding electric to pass up through the chains, crane hook, wire cables, etc. and into the motors, electrical connections etc of the crane and cause problems? Should some type of insulating device (such as a nylon strap) be used to isolate the crane from the project?

[HWooldridge]

The welding circuit is made from stinger to ground on the machine. I do not think you would have a problem if the ground was not placed above the hoist. However, I would use a nylon strap anyway as they seem friendlier than chain on both hoist and work since they are plenty safe and so much easier to use. Then the welding ground has to be good or you'll get no arc.

[irnsrgn]

Making a mountain out of a pimple on this ground thing. The last thread on it was hilarious. Just use common sense and place your ground close to where you are welding. If in doubt touch the rod at the point you are gonna weld and then touch the ground to the place you are gonna put it, if it arcs, you got it right.

[arftist]

Along these lines, it may be worth mentioning that many modern vehicles have computers on board, if welding to a vehicle with a computer, at least disconnect the battery leads.

[Jose Gomez]

One thing to remember is that nylon straps are actually quite delicate and easily damaged by welding spatter, sharp edges, and heat. If you do decide to use one around welding/forging equipment do not forget to inspect it prior to use and be mindfull of it while welding/working.

[Glenn]

Thanks for the reminder to disconnect any vehicle's computer before welding on it (the vehicle).

[Joe H]

Disconnecting the battery cables will have absolutely no effect on anything, think about it for a minute. This is a myth. I've welded on plenty of vehicles with no trouble. Lots of guys with welding rigs use thier trucks for welding tables on a regular basis.

Glenn, there is nothing to worry about. I've personally welded ON electric motor cases, the only worry is from too much heat getting to the wiring. We use cranes pretty much every day installing our signs. Use the crane to postion the part, weld it in place.

[Glenn]

what about the suggestions to disconnect batteries from one car when jump starting the other or the computer etc gets damaged?

[Justin Caradoc]

I have never had to disconect the batter when jump starting. The computer in a car has a "surge" protector between the computer and the battery/ alternator. If that battery explodes it could cause an EM puls and kill the computer but not a simple jump start.

[Dodge]

Since we've gotten off the original subject I would also agree with Justin. I have jumped from one vehicle to another, both with computers, many times. No ill effects. I have welded on a structure suspended by a crane and the chain got hot. Smokin' hot!! Forgot to attach the ground clamp (Boy! Was I embarrassed when I had to call maintenance to replace the fried crane motor *red faced grin*)