Try to repair or not and identifying

[Blacksmith village]

Hello, this is my latest find. I got it for pretty good money ($120), it's a European (French) vise that's over 100 years old as far as I've seen. If anyone recognizes from the picture, I would appreciate any further information. There is a yt video of someone restoring the exact same but slightly smaller one. This one weighs 52kg (115lb) and the jaw width is 165mm (6.5"). The problem is with the jaw. It looks like the jaws are forge welded on it. One is cracked in that spot. I have no idea what the material is, but jaws must be some carbon steel. How to fix it? If  fix it at all. You know the saying: if it works, don't fix it. This thing can be quite critical for welding. Thanks for any sugestion.

[M3F]

Looks like it's been machine welded, not forge welded. Maybe weld the rest of that crack?  My only concern would be hammering on a piece while it's in the vise as is and opening that crack up. 

When you say restore what are you planning?  If it's operational I would maybe clean it up and that's it. As far as what steel it is, someone else may know but all steel is carbon steel, some is high carbon, some is low carbon. 

[Blacksmith village]

Yes, the first plan is cleaning with a brush, then BLO. There are no other things to notice except for the slightly worn spindle, which should still survive me. This crack worries me. Of course yes, steels have carbon, I meant high carbon steel. High carbon steels are difficult to weld. But there may be some other steel that causes even greater problems or is impossible at all. Does anyone know what kind of steel vises were usually made of? (mainly in Europe). Do you think it is machine welding? I need to clean up around this place. So far, only one joint line is visible. Maybe it's true. This peeling part looks like a weld has peeled off.

[caotropheus]

I am not sure, but from the picture it looks like those jaws were welded before. There is one smashed corner on one of the jaws, why not try to spark test that corner with a grinder? If the whole vice is mild steel, you can open a chamfer and full penetration weld the jaw to the vice body. You can also repair the smashed corner. If the jaws are not mild steel, heat them up before welding and let them cool slowly to avoid cracking.

Good luck and lets hope the whole thing is mild steel.

[Blacksmith village]

There is this line symmetrically on both jaws (even with the identical vise that someone on YT restored, these lines are visible), from this I conclude that the jaw is factory welded, probably from a better hi carbon material. I can only hope that the frame is mild steel. Hardened steel is also impossible to weld.

[Daswulf]

Most times the body is wrought iron. The jaws might be steel. Spark test would tell you more. 

If it works fine clean it and use it. If you are concerned about the crack and not sure of wrought iron vs. other steel types you could clean it up and braze it. That would make it more solid and much less likely to break in use. 

 

[JHCC]

What Daswulf said. Don't make the solution worse than the problem.

[Blacksmith village]

Yes, I am not heavy user and these vise is oversize for me. So I think it will survive my work as it is. I can really do more damage at this point by trying to fix it. But that unpleasant feeling is present. Brazing could really be the solution, as it does not interfere with the base material. And if the carrying capacity is 30% higher, it is better than nothing. But the crack is impossible to clean.

[anvil]

I agree with Daswolf and JHCC. The body is most likely wrought iron and there is a good chance the jaws are a high carbon steel. 

The tried and true anvil repair method by Robb Gunther will work here if you want to fix it. His fix uses two rods that will do well welding wrought and high carbon steel.

https://www.anvilmag.com/smith/anvilres.htm

[Blacksmith village]

anvil thank you for suggestion, I will check these method. But I can see that it is far from being as simple as welding two mild steels. It will also be very difficult to recognize steel. With the spark test, so far I can only distinguish between mild steel and high carbon. These crack will probably have to wait. That it won't be as JHCC said, worse solutin than the problem. 

[Blacksmith village]

It's been a while since I posted. I have a lack of time. I did some cleaning, but left the jaws as they are. I still have to make a stand, but I don't know how to make it stable enough. It turns out that the thread is also quite worn. As for its repair, I have the option of making a new spindle with slightly lower costs, but I don't know it will cost more than whole vise.