Seasoning new Japanese chisels

[Adriaan Schepel]

G'day all.

First time posting here etc.

Nice place you have here.

Now down to business!

A friend in Japan has sent me a stack of Japanese chisels made by Kakuri. These chisels are cheap, but Kakuri has an excellent rep for value-for-money tools.

I notice that some of you 'season' your Japanese chisels with some warmth before first use.

Question 1: Are my cheapies worth the trouble? Will it make a scrap of difference?

Question 2: If I do them in my oven, what temperature? For how long? Do I put them in when it's hot? Or do I let them warm up with the oven? Do I pull them out after a certain time? Cool them somehow? Or do I turn the oven off and let them cool naturally?

Looking forward to sucking the marrow out of your expertise!

Cheers from a pokey little town called Sydney,
Adriaan

[harry strasil]

Are you saying the chisels are too hard and they chip or nick from being brittle? I would try them first to see how they are first.

Tools are draw tempered after they are hardened so that cutting edges are not brittle.

Wood chisels are usually draw tempered to a straw color, which is between 400° and 450°. To do this remove handles put in a 400 or so degree baking oven and leave for 45 minutes to an hour. remove and let air cool or quench in 120 degree water cutting edge down and stick straight in or they will warp.

[Adriaan Schepel]

G'day Harry.

My chisels are still sitting at my local post office, awaiting collection.

I have just noticed that some people on this forum speak of 'seasoning' their Japanese chisels before first use.

I notice Pam has mentioned sticking them on a hot tin roof for a few days, and someone else mentioned whacking them in the oven.

I gathered that this was to prevent any chipping from initial use i.e. a preemptive step to preserve that straight edge from the word 'Go'!

But then others speak of an initial edge which is normally flaky (and to be expected) before honing back into the 'sweeter stuff'.

Help! What do I make of all this?

Cheers,
Adriaan

[harry strasil]

Adriaan, I believe what they are talking about is, if care was not taken when grinding the bevel, the end gets to hot and removes the temper for a little ways back and thus makes the steel softer, I believe they are carefully removing this affected metal to get to the part that will hold an edge. Basically the bevel grinding got the metal hot enough to anneal or soften it for aways.

When making chisels, knives etc that need a good edge. After forging to shape, the tool will be annealed (cooled very slowly over night) in wood ashes, vermiculite or such and then the tool is normalized 2 or 3 times ( heated to a bright orange) and let air cool. Then it is brought up to non-magnetic 1460°, and quenched in water, brine or oil. This makes the steel very hard and brittle. To make it servicable as a cutting edge, some of the brittleness must be removed and a little ductility and toughness must be imparted to it, this is called draw tempering. Some smiths will rough grind to size before hardening and tempering and then finish grind or polish after tempering.

[Pam Niedermayer]

Yeah, what Harry said. I may have mentioned putting them on a roof in passing, as I've heard some recommend/joke about; but I've never done that. Sorry to have mislead.

Pam

[Dave Burnard]

As a longtime user of japanese chisels - I've never had to do any retempering. So go ahead and use them. Remember japanese chisels are supposed to be harder so they will take a keen edge and hold it. If you're used to using soft chisels you should remember to do a little more chopping and a little less prying with your new chisels. It's much easier to increase the bevel angle a few degrees to cope with minor chipping than it would be to retemper - if you get the temp wrong you might ruin the chisel. And if you want softer chisels - just get some blue chips.

As a blacksmith and toolmaker - you shouldn't have to do any retempering.
The chisels will have been tempered already. You might stumble on a defective chisel where retempering might help. Or you might decide to use the chisels for something other than woodworking, like say opening paint cans :o then you could retemper.

Just use 'em - that's what everyone I know does!

[Adriaan Schepel]

Thanks, guys. Once again, the dumb Aussie falls for the 'chisel on a hot tin roof' joke. ;)

I picked up the gear yesterday. Nice. A little Gyokucho Razorsaw that I got my friend to throw in (see above pic) only cost the equivalent of approx $US18.

Hey can anyone tell me about the striations (picked up that word from CSI) on the backs of my chisels? Is it part of the forging process, or decorative, or what? Looks cool.

Also ... why the black section? What makes it black? Is it rust-prone? Or rust-proof?

Last one ... getting rid of the cosmoline. I've heard a few people say they use boiling water or steam to do it. This shouldn't have any adverse effect on my chisels, should it? Maybe you have other ways of doing this which you can share here.

Cheers from a pokey little town called Sydney,
Adriaan

[philip marcou]

Yeah, what Harry said. I may have mentioned putting them on a roof in passing, as I've heard some recommend/joke about; but I've never done that. Sorry to have mislead.

Pam
Lol. You merely have to maintain the roof at a temperature of about 400 degrees cent. for about one hour to bring them down to RC55 or so....One can be having some bread baked at the same time.

[Bruce Page]

Good edit Ken.

[Charlie Mastro]

Thanks, guys. Once again, the dumb Aussie falls for the 'chisel on a hot tin roof' joke. ;)
TRUE:)

Hey can anyone tell me about the striations (picked up that word from CSI) on the backs of my chisels? Is it part of the forging process, or decorative, or what? Looks cool.

Are you talking about the hollows or the tool marks from scraping out the hollows?

Also ... why the black section? What makes it black? Is it rust-prone? Or rust-proof?

Just the way the forging was left. They will all rust if you get them wet or store in high humitity.

Last one ... getting rid of the cosmoline. I've heard a few people say they use boiling water or steam to do it. This shouldn't have any adverse effect on my chisels, should it? Maybe you have other ways of doing this which you can share here.

You sure got some strange advice. :o In all my experiences they only have laquer on them and you would use laquer thinner to remove it. Then you will need to set the hoops so they won't come off when you are using them. Try this link:
http://www.toolsforworkingwood.com/Merchant/merchant.mvc?Screen=NEXT&StoreCode=toolstore&nextpage=/extra/setting_hoop_guide.html

Cheers from a pokey little town called Sydney,
Adriaan

I am trying to post this reply and keep getting a dialoge box saying my reply is too short. Anyone ever see this before? It may be because I answered the questions within the quote?

[Adriaan Schepel]

Okay, everyone gets a laugh at the expense of the Antipodean. :rolleyes:

Mr Marcou - if the bread you bake is as nice as the planes you make, I'll take a half dozen!

Charlie - the 'striations' I refer to are on the black back part of the chisels ... like fine long lines etched into the metal which can only be seen on closer inspection ... sort of a 'wood grain' look.

The cosmoline has been used to coat some of the blade to protect it from rust in transit and storage. Tips on removal?

Oh yeah - and just why is the forging black? And does this flake off, or is it inherent in the properties of the metal?

Cheers,
Adriaan

[Dave Burnard]

Charlie - the 'striations' I refer to are on the black back part of the chisels ... like fine long lines etched into the metal which can only be seen on closer inspection ... sort of a 'wood grain' look.

The cosmoline has been used to coat some of the blade to protect it from rust in transit and storage. Tips on removal?

Oh yeah - and just why is the forging black? And does this flake off, or is it inherent in the properties of the metal?
Adriaan

The lines you're seeing are probably the marks left over from the grinding done to finish the shape of the chisel. The hollow on the flat back probably shows them as well. If the hollow is black it was cut before hardening, it the hollow is silver it was probably cut after hardening. (It doesn't really matter - more of a cosmetic preference.)

On very expensive chisels there might really be a wood grain finish either from etched old wrought iron, or modern mokume (pattern welded) materials.

The black surface finish is what happens when the chisel goes through the heat treatment process. It's basically an iron oxide, just a different one from rust. It's a traditional finish on japanese chisels and is fairly permanent - unless you scrub with something like steel wool or a scotchbrite pad.

Like Charlie said, it's probably not cosmoline but more likely a lacuer. If it's cosmoline it will come off easily with paint thinner. If it's laquer you'll need to use something like nail polish remover, acetone, or laquer thinner. If it really is cosmoline - get it off. But if it's lacquer...

Here's a confession from a long time japanese chisel user - If the laquer was applied in a nice thin coat with no streaks or drips, I don't actively take the laquer off (the horror!) except on the bevels. It helps prevent the body of the chisel from rusting and keeps the chisel looking nice. Handles I could go either way on...