Arc Welding and your vise

[Glenn]

I have often heard that arc welding can cause damage to your vise.

If you clamp your negative lead directly to the work, there is no problem.

If you clamp your negative lead to the stationary jaw of the vise, there is a problem as the arc will jump from the jaw to the work and create a small spot weld to conduct the electric. This will eventually pit the jaw face.

If you clamp your negative lead to the moving jaw, the arc will jump from the moving jaw, or the screw, to the work and create a small spot weld to conduct the electric. This will eventually pit the jaw face or screw.

If you clamp your negative lead to the work table, the arc will jump from the work table, the vise body, or the screw, to the work and create a small spot weld to conduct the electric. This will eventually pit the screw or vise parts such as the jaws. The big problem comes when you have a vise that rotates, moves on a plate, where the arc jumps from the bottom plate across the bearing surface to the top rotating plate. This can cause pits on the rotating or bearing surface, as well as pits on the vise jaws.

What is your opinion on the issue?
Any references that could be used to back up your opinions?

[ThomasPowers]

So if you just put on a jaw cover with a tab to connect to the welder you avoid all this?

[pkrankow]

If you have a problem getting a good ground using a twisted pad of heavy stranded copper wire between the clamp and the work can sometimes help. The pad makes for many many points of contact and can provide a better connection. I took a piece of about a foot of an old #4 lead, stripped all but about 3 inches in the middle, folded it back on itself around a rod and twisted it up some. This also helps with grounding an irregular surface because the pad is bigger than the clamp, and evens out highs and lows a little.

Phil

[jaebo74]

I have heard of this before but I have never had this to happen . The jaws of the vise usually make enough contact to ground the material . You must remeber that most of the current is spent (through resistance and heat generation )actually doing the work of welding , leaving you with only a little current to go back to the machine . If the pitts were being made, I believe you would need a microscope to see them .

[Rich Hale]

I use a wilton vise that I bought used in 1965 and have use as a welding clamp for all this time. I ground to the base plate and have never noticed a pit of any kind. Any damage done to the jaw faces are from me without the use of electricity. Reading this I think that if the jaws were not tightened it would do as mentioned above.

[Timothy Miller]

I think 4 1/2" grinders, files and hacksaws do more harm to vises arc welding in them. Though weld splatter and weld blobs are no good for them either. I make it a point to clean and lube up my vises about once a year and remind the guys not to abuse them on a regular basis.

[ThomasPowers]

Neatest trick for post vises like the Columbian whose screwboxes are open in the back was the fellow who brazed a cap on the end with a zerk in it and so greases the screw from the closed end pusing any crud out the front.

[Ten Hammers]

This vise / swage stand sets by itself. It has a piece of 3/8 rod welded from the back of it (see right corner of swage) connecting to the main shop table (which has the ground clamps from the mig, stick and plasma attached to it). Countless welds done in the vise. No issues with vise. I have welded TO the vise and then tacked on to further part setting on the floor for repairs or whatever. You want good weld, you need good connection. Notice no exposed screws on the vise as well.