Vice Repair - cast iron welding

[jakeru]

Hey guys - I picked up this vice in a frozen and abused state. I unfroze it, straightened a rather bent acme screw (for the most part straight), and also really securely seated the forged steel acme nut into the main body (by grinding down its tapered surfaces so they more fully engage the corresponding wedged surfaces inside the cast iron main body.


Now, the vice has good strong clamping power it seems, but its jaws are pretty sloppy, and there is a crack in the back of the main housing (I believe caused when the vice was opened too far, and then jammed closed.) There seems like excessive slop in pretty much all the sliding points, including the opening below the crack.


With some .055" shim and an .065" shims inserted on either side, it eliminated about 1/4 turn of handle rotation to get the vice jaws to clamp. So I think it's be nice to eliminate this play.


Is there some reason to purposely leave some clearance in the sliding parts? (Any reason why not to take it down as close to zero without binding as I can?)

I am considering using TIG to apply either some nickel-55 rod or some aluminum bronze A2 rod, and then use a big aggressive flat file I've got to manually machine down to desired clearances. The friction "pads" on themain vice body that would need to be built up arenot large - maybe 3/8" x 3/8" square each.

The bronze might "machine" easier than the nickel-55. But, would the nickel-55 be possibly hold up better to sliding friction? I know bronze can be decent for enduring sliding friction, so maybe that would be fine for this, and the way to go. The nickel would be a better color match, but for this vice, I don't really care. Any thoughts or recommendations?

If I went to the effort of welding, I'd probably also vee out the crack and attempt to weld it back up as well. And there are some friction pads at the front of the main body I would consider building up (to better align the moving jaw with stationary jaw) as well.

Since this is just a second vice, (and not any recognizable brand), it wouldn't be a big loss if I made a mistake. (Cracking the cast iron vice body is really the only potential concern I have on this.)