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On your Jap chisel.... I found a post from Ron Hock where he recommended using an electric deep fryer (like a fry daddy) to temper small steel like chisels. You set the temperature on the dial, let it heat up a bit, then fry your blade for an hour or so... He recommended 300-325 for chisels.... Said it would take O1 to Rc 62 range - which sounds just about right to me.... 350+ would push you down below 60 - which is hardware store paint can opener chisel soft.

A brief update.

I went ahead and rehardened 2 more buck brothers chisels.

Process is getting better.

1. Flatten and establish the bevel grind before hardening. This results in a lot less work after hardening.

2. I sat my oil container in a big bowl of water to ensure it wouldn't get too warm.

3. Torch Heat only the first 1" of the chisel or so - which results in about 3/4" hardened. There will be another half inch or so behind that left ugly. Try to heat as evenly as possible to nonmagnetic then quench. And cool.

4. Check with a file to verify. Yes. hard..

5. Check for warp.. Yes - it warped a little, but it's enough to clean up reasonably quickly.

5. Re-flatten and regrind the bevel, then hone. This is on a machine - so made sure nothing got remotely warm.

6. Strop. Razor sharp and pares very nicely.

Here's a pic of the finished chisel.





And here are a few nice pics of how this can go all wrong.

Here's one of the Harbor Freight chisels that I heated too much (almost 4") and ended up warping it really badly into a banana when it quenched... This one is a total loss....


Here's one of the water hardening chisels that went banana on me. This one is a total loss as well....

Brace carving chisels on the cheap!!! John, you have a gold mine there.

Here's an interesting video showing how these Buck Brothers chisels are made. Turns out that they are induction hardened and hot water spray quenched.



I did decide to temper the LMI chisel. The edge was too chippy and would chip when paring cherry or even spruce. I gave it a go in the French fry pot for about 1/2 hour at 325F. We will see how this does. Initial indications are that it's not as chippy. It looks like most reputable steels will be somewhere around 62-63RC at this temperature.... Which is about what I want.

This may have been covered by more knowledgeable people but,
From what I understand, you have to heat 150deg above non-magnetic… so after the magnet fails to stick heat under torch or in a forge a while longer… a minute or two… and then proceed with quenching. (Oil)
Twice normalizing (heating to non magnetic the slowly air cooling, repeating after a couple hours) prior to your heat/quench run,
is supposed to help the steel be better as edge tools. Ive never tried this but many knife and tool makers swear by this.
Also baking in a oven "twice" at 400deg, after quenching, is a method many use as well.
cheers
charlie

An update on my too hard Japanese chisel.
As a last effort before popping it in the oven. or sending it to John for his valiant efforts, I dug out a fine water stone I used years back when I was willing to spend more time on sharpening. I remembered reading something about diamond stones damaging Japanese edge steel. Sounded like bunk to me at the time. I don't know if it was the softness of the stone, or how water stones cut so quickly with so little pressure, but I got an un-chipped edge on my chisel. I took a paring cut across some end grain expecting it to crumble but it didn't. For now it's in the game but it's on probation. And it's sent me on another sharpening media wild goose chase.
Now there's a subject with no end.

Glad to hear it worked out with the Japanese chisel.

It sure sounds like there is no escape from the rat hole of owning every single piece of sharpening paraphernalia in existence. ...

Here's another update.

I tried to see if I could heat up 2 of the Harbor Freight chisels to get them to warp the other direction. Well - they split on the water quench. :0 One split down the tip and the other across the chisel... I am down to 2 of the 6 chisels out of that package. The narrow one was the only one that heat treated OK in the oil... Probably because it was thin enough for the quench rate to work out. The other was too wide and I didn't fool with it.

Here's a couple pics of the Harbor Freight remnants.





Kerpow. This is a good reminder that this whole process is not without risk.....

Good deal, hope it keeps working. My dad always had a large busy wood shop and one of his talents was getting an edge on a cutting tool, he always used oil stones, elbow grease, and a good strop. I've graduated to a combination of water, diamond stones and a Tormek T-7. I rarely damage an edge that needs reshaped on the Tormeks water wheel, however the leather wheel hone feels like cheating, thirty seconds with the right technique and its scary sharp. One of my Lie Nielsen planes blades took forever to flatten, and when I finally got an edge it chipped. I was about to box it up to send back. I decided to grind it back a full 1/16" and its working like it should, sounds like the annealing was off a few degrees.

Tools with alloy stools e.g primus/ece chrome/vanadium steel seem to do better at sharpening with diamond stones . american/british older plane blades/chisels can be honed to 4k on either japanese water stones, oil stones , natural stones or diamond stones.. The laminated steel blades of japanese and chinese blades/planes seem to work better when the hard steel backing is brought to a bright polish on a 8k or higher natural or synthetic waterstones. I/m using more methods these days , as I figure out the best sharpening system for a particular tool. This seems to be a conundrum. There are so many different types of tool steels on the market these days .I have to experiment which system works the best ? diamond stones ?? oil stones , natural stones,, synthetic waterstones, ceramic stones . . Slow speed wet grinder ?. I/m going to buy a granite surface plate on the recommendation of my machinest friend. I upcycled a chunk of aluminum with 120 and 180 grit sandpaper to true. and flatten metal and wood planes. Even my L/N #4 smoother had a convex bottom after 15 yrs. Sharpening , and all the skills that go with it cannot be underestimated. In japan woodworking apprentices spend months and hours to learn how to sharpen properly!

The demands of repair have moved all my romantic geppetto sharpening stuff into drawers in remote places, leaving diamond an ceramic stones at the ready. Flattening chrome plated parts, sharpening carbide, making various pokers and stabbers, altering wrenches and chisels to reach remote location,etc.
I'm still a little skeptical a steel needs a stone with a matching nationality. I have had to grind back new edges before they started working but I've never taken off 1/16" before as Clinchriver describes. Maybe I just never went far enough on this one. Time will tell.
I had forgotten how well water stones work. I may have lost something over the years in my over simplification of sharpening as Ernie suggests.

"Sharpening , and all the skills that go with it cannot be underestimated" ain't that the truth?

So then....

I think this leads us to a rational conclusion.....

You can either buy the tools and then buy the additional sharpening setup to handle them.... Or you can buy or modify tools which cooperate with the sharpening setup you already have.

I am very happy with my hardened Buck Brothers chisels. They are seriously hard and cooperate with my sharpening setup. Now - all I need to do is sort out handles.

John, I have settled on a easy to make handle with a shape I prefer. I tried to find some pictures of making them but these are the best I could find. The handles are basically a copy of the old Berg red plastic ones. The basic shape is a sort of oval in cross section. Actually more of rectangle with rounded corners. I use the table saw and a router table and then shape the front or nose by hand or with a lathe. Some of the ones pictured have fancy caps that look cool but aren't necessary at all. FWIW The caps have a tenon in them to strengthen the end grain joint.
I like this shape because it feels good in the hand, won't roll on the bench and has a wide face and back with narrow sides which informs the hand of the chisels orientation.
Some of these pics show taking the handles of off some Two Cherries chisels. First pic is the Berg plastic handles that inspired me. The wood one is another simple handle idea. Anyway maybe something there to see.

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Cut to size.....Beat to fit.....Paint to match.

Nice work !!

The ones in Link's post with the ebony caps are what he made for me and one of the most prized things I have! Thanks again Link!

Dave didn't get ebony caps.....

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Ann Arbor Guitars

And just in case you thought this was over and done... Of course it's not... And as usual - there's another wonderful rat hole hiding here.

Oil choice.

Apparently - Ignorance is .... And I was pretty ful here.

Olive oil is a good "Medium speed" oil that's useful for oil hardening steels... But it's heat transfer rate isn't good enough for the faster quenching steels....

Allegedly - warm (130F) canola oil is the next one to test.
Warm to reduce the viscosity a LOT... But it also actually speeds up the heat transfer properties of the oil.

Now.. Apparently warm canola isn't as good as bespoken industrial quench oils... But it's in my cupboard.... (Shhhh... Don't tell the wife!). This is a lucky coincidence... As canola is perhaps the worst cooking oil that's sold as actual cooking oil...

That means there's more of this test to go..... I want to see if I can properly harden the ones that wouldn't harden right in olive oil... Why? Water is a really HARD quench ... And like I ran into - anyone who has to resort to water will likely see a LOT of fallout from both cracking (check) and severe warpage (check).

Stay tuned.

Peanut oil.

_________________
Cut to size.....Beat to fit.....Paint to match.

Peanut oil.. Good to know.

I like those handles. Those are sharp.

Oh... And if any of you knife guys are willing to part with a quart of Parks #50 - shoot me a message.

Another brief non-update... I haven't tried the canola yet..

I do want to show the difference in color perception based on the available light.

These pictures were taken immediately together. First with no flash, then with flash.

This shows what you see, and the colors are about right on.. I was doing this at night outside - so I "saw" Orange at non-magnetic... But with the flash - you can clearly see the color is definately not Orange when the lights are on - more like red.... Still the same temperature, still nonmagnetic.

The funny looking glow/flare around them is the torch flame
These were in the flame when the pix were taken.

No flash, dark outside... Orange...


Flash on. More like you would see with the lights on.. Red.

So.... The promised Canola oil update.

The banana Narex chisel hardened in warm canola. It wouldn't harden in olive oil.

The Harbor Freight chisels would not. The only way I have been able to harden those is water. And they crack like crazy in water. I even tried brine, warm water, and warm soapy water. Crackity crack.

So... This is the end of the road for the Harbor Freight chisels. They appear to be a good enough value for a beginner set - assuming you have the time and patience to sort them back out. They take a lot of work to flatten the backs and hone them.... But - thats about all you can get.... They are what they are and that's the end of it. If you get a "good" set - great. If not - about all you can do is to throw them away and buy something else.

Several of you guys told me the same about the HF chisels.. I appreciate that... You were right. I just couldn't leave well enough alone.

Thanks

Another semi-update.

I decided that full hard was too chippy. You have to be very careful with your technique so you don't twist or pry at all. The edge was super hard - but would chip away if you messed up even a little.

I went ahead and tempered these back at 400F. They are still much harder than chisels in the store, but they don't chip nearly as easily. I call that a success.

Here's another update, this time on a hardening job I did about 6 months ago.

I was making a couple of drilling jigs, just flat plate will a couple of holes in. The plates act as drill guides to get accurate spacing of holes in multiple components.

For the jigs, I used a W2 steel, bought specially for this job. W2 means a water hardening steel; i.e. for once I knew what the steel was I was trying to harden. I made the jigs, heated them to dull red and water quenched them. They hardened well and I use them on the drilling job.

This week, I had a repeat of that job and pulled out the drilling jigs. One had deep cracks in each side between the holes (but was still holding together), the other was badly warped, but no cracks.

So, even with the "right" steel, a water quench is a pretty severe stress raiser, which you may not see the impact of immediately. Presumably, in an industrial situation, the water quench is much more controlled, e.g. a water spray or similar.

I re-made the jigs and used an oil quench this time. They got a bit harder, but not much.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Not really. Water hardening, as you just found out, is not that stable. It is usually used to save $$ on material, and processing, for either a one time use or parts that really aren't that critical, like a wear pad. So unless it is going to go into a production furnace with different stations, having the parts shuttled by a conveyor, its usually a tub of water in a tool and die shop. Oil hardening is much more stable and still affordable. I commonly used this for drill fixtures and it works fine. Never had problems holding +/-.001 in hole location and size. Some of those fixtures I used for over 20 years and they produced 1,000 of parts over that time, no problems, no cracking. Oil hardening is termed a tough tool steel, meaning that it will stand up to some abuse, and the hardness can be controlled. A normal tool selection chart runs water hardening-oil hardening- air hardening. Water hardening being the hardest and least stable, air hardening the most stable. Remember that hard=brittle. Oil hardening is the happy medium. For a drill fixture you really only need to be harder than your drill bit. Air hardening is only necessary on very close tolerance tools with thin cross sections.

Tim

After all this - I really have no desire to fool with water hardening steel any more. It's just too much trouble.... And at least from my perspective - no benefit at all... As Trevor pointed out - you aren't even necessarily out of the woods even when you think you are.

So Trevor.... I went on over and asked about doing this on a couple woodworking forums.... Seems I stirred up a bit of a wasps nest.. But I also got to see a bit of how different cultures work..

On the USA board - I was told by 2 professional metallurgists and one long time tool maker that what I was doing was not possible... Providing them proof that I had in fact done it in real life and that this wasn't exactly a new thing either didn't seem to convince them to at least consider the possibility.... Several other people eventually chimed in that they too had done things like this and it worked out fine.... None of that was able to persuade the naysayers that potentially ruining a $10 chisel (new, not antique) for the sake of "science" wasn't the apocalypse.

On the Australian board - it went much the same until I revealed that I had been told about the method by an Australian luthier... Well - since it was done by an Australian, it must be OK then.. At which point they poked around and found your original post over on the ANZLF... They all changed their minds and decided it was provisionally OK and probably a worthwhile thing to do so long as you weren't out to ruin antique or high end steel....

Lol... Amazing the difference in culture...

Yes, it's amazing the xenophobia we see in our well-connected world!

Regarding the technique, I was told it by a friend who custom makes chisels (he kindly made a superb paring chisel for me). For the steel, he used metal cut from a 19th century 6' or so diameter circular saw, used originally in a bush saw mill. Not sure how that would go down with the "antique steel" fellas!

Going right back to the original story, you may remember I had it in mind that alloyed tool steels couldn't be re-hardened. I most likely learned that off a professional metallurgist!

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au