Heat treating old Ward chisel: Bad idea or not?

[yetanothersmith]

Hi all,
I need your collective wisdom please.
I'm potentially looking to make a Kiridashi type marking up knife for my brother-in-law from an old Ward pig sticker mortise chisel (he is himself a Ward).
It bears the tool mark 'WARD WP WARRANTED' but I don't know its age. Any ideas?
Firstly will this be high or (high-ish given its potential age) carbon steel?
Is it likely to have undergone some form of hardening?
And finally, if not, would it be possible to harden it and, if so, how would I best go about this without access to a forge? The best I can manage is a MAP gas torch and a domestic oven.
Thanks in advance.
Cheers,
Pete.

 

[Dee J]

Isn't the essential parameter of a Kiridashi knife the laminating of a very hard high carbon steel to a low carbon backing? Is that the nature of the chisel blade?
But any edge tool like an old chisel will be made from some sort of high carbon steel which will have been hardened and tempered, and if you need to anneal/reharden/temper then a map gas torch could do that. Exactly what the steel is and what parameters apply will be educated guesswork.

 

[dannyr]

Ward (WP=Ward&Payne) made laminated steel pig sticker mortice chisels from approx mid 19th to mid 20th C and maybe some later solid carbon steel.

Are you proposing also to forge this into shape?

 

[D_W]

It will harden with a can forge (paint can, and refractory blanket or kawool liner, but how much length you can harden is a good question).

I harden almost everything I make with one or two TS4000 or TS8000 bernzomatic torches and propane (mapp for something that needs to be a color or two hotter).

you need a magnet. you will likely need a quench oil to get whatever ward used to fully harden (parks 50 or the equivalent over there). You might get away with water, but likely not (cracks and that will be a terminal issue - you may even get a spectacular show and get a sound that sounds like a stick breaking under water and get one chisel becoming two just in the quench).

And finally, expect some warping if you manage this - if there are bevels on the chisel already, then you may get a lot of warping. I'm sure they were ground after chisels were fully hardened. I"ve learned this the hard way.

Not telling you not to do it - you can get very good at this and it may be a gateway into fixing or making things. With simple steels, you can match commercial heat treatment with some experience and be more accurate than most commercial specs.

If you are still with the process here, what you do is as follows:
* heat the steel evenly until a magnet doesn't stick
* continue to heat a full shade higher (this should take place over 30 seconds, not 10 minutes - the last heat ramp up - nothing good happens if steel is past temperature for too long)
* immediately quench straight into a quench tank (I use a paint can with a gallon of parks 50)
* the action into the tank is straight in - no side to side. If you work side to side, the chisel will warp with a side warp
* within about 30 seconds if the whole thing is cool (relatively) take the chisel and either toss it into the freezer or finish cooling as much as possible in water
* once it's cool (30 minutes in a freezer is fine- just a little while, a minute or so at cool if you use water or ice water), temper it in your kitchen oven at 375-400F.

It should end up about as hard as it was originally.

Chance of warping is high. It may belly some due to the warp and you may not mind it (I don't if it's minor).

Beware of processes for hardening and tempering that aren't as particular as the above, as someone may be talking about O1 steel or a car leaf spring or whatever and have low expectations. What's in ward will be a different animal - it's not O1 and will not attain full hardness as easily.

 

[yetanothersmith]

Isn't the essential parameter of a Kiridashi knife the laminating of a very hard high carbon steel to a low carbon backing? Is that the nature of the chisel blade?
But any edge tool like an old chisel will be made from some sort of high carbon steel which will have been hardened and tempered, and if you need to anneal/reharden/temper then a map gas torch could do that. Exactly what the steel is and what parameters apply will be educated guesswork.

Thanks for the reply. I'd say it'll be more Kiridashi shaped than true Kiridashi!

 

[raffo]

If it's a laminated chisel, the steel will be "cast steel", the bulk of the chisel will be wrought iron. Look into the anatomy of this type of chisel and decide if it can go from a laminated pig sticker to a knife.

A Ward paring chisel may be of a shape that could be cut and turned into a chisel.

 

[yetanothersmith]

Ward (WP=Ward&Payne) made laminated steel pig sticker mortice chisels from approx mid 19th to mid 20th C and maybe some later solid carbon steel.

Are you proposing also to forge this into shape?

In all honesty the the shape of the chisel blade is not far off what I want anyway so I'll just need to grind a bevel (without overcooking the edge) and round off the other end. Shaping through forging is above my current technical ability. I was more wondering if I could improve the edge holding ability through heat treatment or whether I just risk making it brittle.

 

[raffo]

I was more wondering if I could improve the edge holding ability through heat treatment or whether I just risk making it brittle.

Ward & Payne were top of the line.

 

[yetanothersmith]

If it helps, this is my starting point...

 

[raffo]

If it helps, this is my starting point...

If it's laminated, only a thin layer on the right side is steel, the rest is wrought iron.

 

[yetanothersmith]

So if its laminated I can basically give it very sharp tip and that's about it!

 

[yetanothersmith]

Is there any sort of crude acid etch or similar that I could do to check if its laminated (which, by the sound of it it, it probably is)?

 

[raffo]

Is there any sort of crude acid etch or similar that I could do to check if its laminated (which, by the sound of it it, it probably is)?

If you fine sand the surfaces and submerge the chisel in vinegar or evaporust, after some time you'll see a difference in color. You'll be able to see the laminated steel.

 

[D_W]

If it helps, this is my starting point...

I didn't read well enough at first what you're doing. If the thing can be sharpened and the edge chips instead of folding, it's still full hardness and you are very unlikely to improve the factory heat treat - they were done very well.

 

[Jake]

If you take off most of the back with an angle grinder or whatever, seems to me you are very close to a single bevel type knife with the hard stuff on the critical side (edit I'm assuming this is a wide enough chisel for a knife).

 

[D_W]

If you take off most of the back with an angle grinder or whatever, seems to me you are very close to a single bevel type knife with the hard stuff on the critical side (edit I'm assuming this is a wide enough chisel for a knife).

near zero chance of doing that without ruining the temper. It can be done on a ceramic belt at high speed without water, but not much (except filing if it's laminated).

 

[Jake]

Hacksaw then

 

[Jake]

I was assuming it is laminated. You'll know better than me DW on this sort of thing, but a taking a cut a mm or so at a time with a 0.8mm type blade would ruin the temper?

 

[D_W]

I was assuming it is laminated. You'll know better than me DW on this sort of thing, but a taking a cut a mm or so at a time with a 0.8mm type blade would ruin the temper?

Yes, though you could grind back from there with a modern abrasive belt. I think the average person will propagate the burn further back. Laying a stack of dripping wet paper towels over it may help avoid burning.

 

[Orraloon]

If that is laminated then being a pig sticker the hard bit will be on the narrow back. That will mean you cant use it for that design of knife. Better check that first. I made a very short old chisel into a marking knife by just grinding a skew bevel with a wet grinder.
Regards
John