Used and abused Robin bench vise

[DPittman]

I have an old 5 inch "Robin" made in Canada 5" bench vise that has had a very hard life. I'd like to fix it to a useable state as it was a really nice made vise with a totally enclosed spindle/screw with cast bronze internal acme thread for the screw which still seems very smooth. Every part of this vise has had years of hammers and abuse put to it. The jaws are totally buggerd and even the casting below one jaw has been busted out. The one jaw has been welded in and both of them have the retaining bolts busted/needed or welded in.
The biggest challenge is how to go about removing the old jaws and then how to deal with the missing chunk of cast below the jaw.

 

[DPittman]

I've ground down some of the welds on the vice jaw and am thinking I'll try to mount it on my milling machine and try to mill out the jaws.
What say you all? Am I asking for trouble trying to mill out vise jaws welds and broken bolts?

 

[RobinHood]

I would mill off the welds as much as you can - leaving the parent cast / steel jaws. Hopefully the weld did not penetrate all that deep and you are now able to remove the jaws.

If the welds really hold, they knew how to weld CI (or maybe it is cast steel?).

You thus know that the busted out piece can be built up with weld and machined to proper shape after.

The vise jaws are possibly hardened. Could be a tough go to mill them off.

 

[DPittman]

You thus know that the busted out piece can be built up with weld and machined to proper shape after.

The vise jaws are possibly hardened. Could be a tough go to mill them off.

Yes that is my hope to weld up the missing chunk and machine down. Not that I have any real successful experience welding cast iron but just more skill building around the corner maybe.

I've got a M42 8% cobalt roughing mill that I'm going to try. I'm hoping it won't be a gong show.

Unfortunately I can't figure a way to hold the vise on my table so I can mill the underside of the jaws where some of the welds are. I will try to mill the top weld off but there are broken retaining bolts holding the jaw in place also.

 

[PeterT]

I can't figure a way to hold the vise on my table so I can mill the underside of the jaws

Tee slot cutter?

 

[DPittman]

Tee slot cutter?

Oh yes maybe that would work (but I don't have one). I do have Woodruff key cutters but I don't think I want to risk/sacrifice one of those for this.

I did some milling but the work moved and I got off kilter. I have it back off now and am going to try some more angle grinder work first.

 

[RobinHood]

Unfortunately I can't figure a way to hold the vise on my table so I can mill the underside of the jaws where some of the welds are.

Use an angle plate.

If you have to, let the vise hang off the side (front or back) of the mill table while it is fixed to the angle plate.

T- slot cutter might be “too nice of a tool” to cut away a crusty old weld.

 

[RobinHood]

I have it back off now and am going g to try some more angle grinder work first.

That should get the bulk of the well dealt with.

 

[PeterT]

I guess I should have qualified by 'inexpensive; T-slot cutter. I'm gambling on some HSS dovetail cutters from the same place but I'm not setting the expectation bar too high.

 

[PeterT]

Just curious because I turned down a somewhat similar vise which had seen some abuse & always had this nagging feeling I should have at least disassembled it. Cosmetically it would have cleaned up nice with some angle grinding & new jaws are no problem. But that particular one must have seen some heavy blows with a sledge hammer because the lead screw was wobbly (bent) so the moving jaw did a drunken walk. I figured a bent screw could be replaced but a buggered nut would be more work. Are these typically threaded the whole way through or just for a portion on one end?

 

[DPittman]

Mine is just threaded for perhaps 1/4 or 1/3 of one end.

 

[Ironman]

Oh yes maybe that would work (but I don't have one). I do have Woodruff key cutters but I don't think I want to risk/sacrifice one of those for this.

I did some milling but the work moved and I got off kilter. I have it back off now and am going to try some more angle grinder work first.

Yes. I cut old welding and welding attempts out of farm stuff all the time with a zip disk. You can buy 6 zip disks for the price of one of those woodruff cutters.
Had a cow panel someone built in for repairs on friday. One side had a few welds that were broken, I ground out and welded them, then I looked at the other side....not a bad looking bead, laid on 1/16" away from the birdsmouth joints. I think he welded without a helmet.

 

[Dabbler]

I cut old welding and welding attempts out of farm stuff all the time with a zip disk.

Prep for machining makes the job go well. A new set of jaws can be made or purchased if close enough to another vise. The zip disk idea to remove the jaws will work very well! Great idea @Ironman !

 

[DPittman]

Well I got the welded jaw off with some more grinder and hammer work. Wasn't so bad and the weld job must have been done by some other the prevoius owne/user of the vise as it looks like it was done fairly well.

However there is big ugly chunks of meat missing. I will eventually be looking for welding advice from those that have the experience with cast, but for right now I am wondering if I need to know whether it is cast iron (ductile) or if it is cast steel to determine proper welding techniques?

I was able to get 3 of the 4 broken bolt studs that held the jaws in out amazingly easy with bolt extractor. For two of the bolts the extractor worked just like they are supposed to. I was surprised. I was glad I had a large enough drill press and slow speed and reversing capabilities of the vfd was critical.

But for some reason the bolts holding the one jaw are only 1/4" and not 3/8" like the other jaw. The smaller bolt made it harder to get the bolt extractor perfectly centered and it was unsuccessful. I continued to drill out the bolt with an 1/8" drill bit hoping that I would be able to somehow break it loose. I must be very close to buggering the female threads and am wondering if I should just drill out bigger and plan on retapping/heli coil those holes. I can't figure out why they would have used smaller bolt on that jaw as there is enough meat they could have used bigger bolts anyhow. Hmmn gotta think before acting...

 

[Dabbler]

However there is big ugly chunks of meat missing.

wondering if I should just drill out bigger and plan on retapping

If you are painting it anyway, you might consider brazing. It is stronger than cast iron, and a little less strong than cast steel used in these things,.

Retapping has the advantage that all your fasteners are the same, it is what I would do, if possible.

 

[DPittman]

If you are painting it anyway, you might consider brazing. It is stronger than cast iron, and a little less strong than cast steel used in these things,.

I did repair a big 6 inch Asian vise that way years ago and it is still holding but it took a WHACK of acetylene to get all that cast up to temperature, this vise repair would be the same, however there is missing material that I would like to build up with weld if that is feasible.
Yes same size fasteners only make sense to me and the back stationary jaw also had through holes for the bolts which makes me wonder if they were drilled out from original smaller size.

 

[Dabbler]

John Nielsen has a great ideas! He bought a cheap electric magnetic contact heater from Amazon - it can reach 700 degrees F, and that gets you a long way to brazing temperature. John Prefers to use high nickel stick welding for the kind of buildup you are talking about. And it doesn't take a whole tank of gas as well. preheat is required though.

FWIW I'd prefer to TIG braze it.

 

[DPittman]

Here is something that I wasn't expecting....in the body of the vise of the cylinder that holds the screw in, was an area that was a very defined area of old grease and crud. I dug at it and low and behold beneath the gunk appears to be a leather strip that would act as a lubricator/wipe for the cylinder!

Edit: it is felt not leather.

 

[Tom Kitta]

John Nielsen has a great ideas! He bought a cheap electric magnetic contact heater from Amazon - it can reach 700 degrees F, and that gets you a long way to brazing temperature. John Prefers to use high nickel stick welding for the kind of buildup you are talking about. And it doesn't take a whole tank of gas as well. preheat is required though.

FWIW I'd prefer to TIG braze it.

I just welded mine few days ago with high nickel electrodes.

My huge vise - all 60kg of it - has welded on jaws that show wear.... Question is , what should I do? Should I leave as is? They are almost flat with cast iron -I could just weld to them strips of say 1/2 metal as new jaws...

What do you guys think? Or I could drill and tap some holes in the old jaw and simply screw new replicable jaws to it.

Or I could mill out the old jaws - nice and flat - and then attach new jaws to it with say 2 bolts.

 

[RobinHood]

Or I could mill out the old jaws - nice and flat - and then attach new jaws to it with say 2 bolts.

That would be my preferred method. Gives you choice between soft-, hard- or specialty jaw plates.