Other: Welding Question

[Dougie]

I hope this isn't a stupid question, but I'm far better with mechanical stuff than electrical. When welding on a large piece (spring perches on to rear axle housing) does it matter if you insulate the axle housing from the concrete floor? In other words, it is currently sitting on steel jackstands on my garage floor. When I attach the ground electrode to the axle, will current going thru the axle grounded to the concrete floor reduce the voltage for welding? Should I support the jackstands on pieces of wood to insulate them from the floor?

[BobPalma]

Nope. Not to worry.

The current seeks the path of least resistance. If you clamp the ground wire to the axle housing and then weld to the housing, the current has no interest, so to speak, in going anywhere other than back through the ground electrode you clamped nearby.

No sense involving any wood that might ignite or smolder with an errant spark. BP

[GTHawk]

I hope this isn't a stupid question, but I'm far better with mechanical stuff than electrical. When welding on a large piece (spring perches on to rear axle housing) does it matter if you insulate the axle housing from the concrete floor? In other words, it is currently sitting on steel jackstands on my garage floor. When I attach the ground electrode to the axle, will current going thru the axle grounded to the concrete floor reduce the voltage for welding? Should I support the jackstands on pieces of wood to insulate them from the floor?

It will not reduce welding voltage. Always make sure you have good electrical contact, no rust, just bare steel for your ground. If necessary grind a clean spot. If I'm welding in a wet area, mud etc. I make sure to keep myself insulated from the item being welded (the ground) and the elcetrode. It's a good practice to habitually follow.

Don

[kmac530]

We weld on concrete all of the time. I am a metal stud framer and we weld alot of our framing together and it is not only sitting on concrete, it is actually bolted with anchor bolts down into the conctrete without even a problem. We do it all of the time.

As others have stated I do not recommend welding while standing in water....BTDT and been hit hard doing it. Maybe that is what is wrong with me? Too much voltage to the brain....well that and all of the concussions from MX racing {more from the MX crashing than racing}

[radiotech]

Makes no difference, just make sure you don't hook your grond to the end of the axle etc. You do not want to run current thru the axle/ diff bearings, if you do you will be replacing them soon. The welding current will cause a spot on the rollers/ races that looks like someone tried to strike a small arc on them and ruin the bearings. Just be careful where you hook your ground cable!

[Dougie]

Thanks for the responses. I guess sometimes I worry too much. Makes sense it will seek path of least resistance.

[52hawk]

I'd be more worried about the heat warping the housing. Take it slow,like a stitch weld-a 3/4 inch stitch,then go to the other side,repeat. some wet rags can act as a heat sink also.

[clarkwd]

Welding on Concrete.

When I was a teenager, I had to change a tractor tire loaded with calcium in the winter. I did the job inside where my uncle did all his welding. I might have spilled a little salt water between pumping it out and back in, but I swept it all up real good and nobody knew what I had done. The next time my uncle had his welder running he got knocked on his butt. He was pretty disappointed in me.
Bill

[GTHawk]

One more thought I failed to mention earlier. Always connect your ground lead as close to your weld as you can. you'll then eliminate excessive arcing to other electrical componets in the vehicle like computers and as mentioned bearings etc.

[Dan Timberlake]

"path of least resistance" -

I think If the source of electricity (or pressurized water) is capable of maintaining high voltage or pressure, then when multiple parallel circuits are attached, each circuit will flow the same amount of amps ( or water) as if the others weren't even there.

Otherwise, when I turned on the headlights driving down the road the ignition would shut off.

http://www.yenka.com/activities/Kirc...0Model%201.gif

[41 Frank]

Always disconnect the vehicle battery while welding also.