WIP: 16" OAL 1095 Chef's Knife with Hamon *updated with final pics 4/10*

David Schott

David Schott

Joined
Sep 27, 2004
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3,041
Hello!

Its been some time since I posted here so I thought I'd throw up this little WIP to keep myself busy!

This knife is a custom order I am filling. While i've been making knives for years, this is my first real attempt at a kitchen knife. I've come to realize that the thin stock and ultra-thin grinds are quite a challenge and pose a new set of obstacles that I didn't encounter making traditional bowies, fixed blades or folders.

The customer wants carbon steel, differential heat treatment, had a design in mind and has a number of balance, weight and materials requirements. Not a problem!

I am starting with CRA 1095 in 3/32. This is some THIN stuff. I was a bit worried starting with an overall thickness this thin, and for good reason! The customer's design called for a 10.5" blade with a height over 2" at the widest.

I quickly mocked something up freehand on the barstock:
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As you can see, I actually am making two at once. I predicted a high chance of failure with stock this thin on such a long blade and it being my first chef knife. Lets hope I don't need that second one!

Since the stock is so thin, I did a quick and dirty bandsaw job, knowing i could grind the steel off very quickly on the KMG:
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I dont have many pics of the actual grinding process, but I do have some observations:
-Grinding steel this thin gets HOT and fast.
-On a 10+" blade this thin, even a small amount of pressure will bend the annealed steel. UGH.
-Grinding while trying to avoid creating a plunge line is a challenge and requires a lot of finesse.

In the end, the grinding went without much fanfare. As usual with 1095, I put a quick 200 grit hand-rubbed finish. I have never cracked a blade with the scratches running lengthwise. I dont know if this is just superstition on my part or force of habit!

Here's the blade at pre-HT thickess which was about the thickness of a dime. Its resting on my 1944 M-Head Bridgeport mill in case anyone is wondering:
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Another shot to give a sense of size. Notice the Norton Blaze belt on my KMG. These are the kings of grinding belts if you have never used them. I find they dont even throw sparks most of the time...just a steady stream of metal filings. Also for you KMG nuts, look at my platen and you'' notice the old platen style of the original design. I've never got around to milling a recess on the left like the modern platen. This causes me problems sometimes but overall I work around it. I think I have one of the original KMGs as mine is marked "KMG-I" on the side and has the old size drive shaft, etc etc.
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I'll stop here for this post. Next post I'll show heat treating.
 
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On to heat treat prep:
Betweel the plast post and this one, I also:
-Drilled handles
-Refined handle shaping more

When doing differential hardening, I use satinite as a clay. I first mix it up with some water and get it to a slurry consistency. I usually first apply an even coating across the blade:
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I then begin "wiping" away the clay to form some semblance of a pattern:
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I usually then add some extra to see what happens:
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An overall shot:
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After drying the clay on the blade with a torch, I fit it up in the oven:
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I have a Paragon KM14D. This knife is 16" OAL. I actually had to cut a small slot in my door's firebricks to get it to fit! This knife maxes out the oven 100%

Here's the oven:
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I heat treat by raising to 1400, soaking for 10 minutes there, then fast ramp to 1430 with a 6 minute soak. I then quench in Shell Voluta quench oil. I tempered for an hour at 375, then 2 hours at 400.

Quench was tough with this knife. My shop is cold and the steel was so thin I stressed over getting it into quench fast enough. All went well during the quench. The blade took a very slight wrap to the left, however. I have never had warpage problems but I think the thinness of the steel is a big contributor here. Possibly also a difference in clay thickness or an angle going into the quench. Either way, I think I can work it out so I am not concerned.

Next: Post heat treat
 
After tempering, I began my final grinding.

Here's the blade after initial scale removal and a quick etch to see where scale remained:

12.JPG


Grinding a blade this long and thin post-heat treat is quite an experience. Overheating was a big concern of mine so I went extra slowly with more water dipping than normal. The blade was looking great and grinding went smoothly. This is the thinnest knife I've ever made and I had to ignore my impulse to leave the edge at a "normal" thickness.

Here's a shot at rough grit, after fully taking scale off:
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If you look really close, you can see two thin lines near the ricasso area of the edge...the hamon was visible even at rough grits. A good sign! There is no traditional plunge on most chef's knives, so I constantly feathered the belt onto the blade. This went much smoother than I anticipated. Its a similar process as creating a "curved" plunge which I had done before.

I continued normal grinding, up to 400 grit. I then switched to hand sanding at 200, all the way to 600. I did this on one side just to get an idea of the hamon. I'll be taking this to over 1000 grit before my final etch which will reveal a lot more "action."

The hamon is an interesting one, with a cool "double" going on near the heel of the blade. I suspect this was due to the interrupted quench I did. In all, I think its a pretty cool pattern!

Next post will come in a few days once i've fully sanded, etched and polished the blade.

There will be stainless bolsters and some locally-sourced handle material. The customer wanted lilac wood handles which I sourced but may be too thin. I'm looking for something spectacular.

Here's where the knife is right now:
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That's big! I'm excited to see it when it's finished. It kind of looks like it's only ground on one side — is this right?

- Chris
 
Looks great David-interesting hamon on this one...What are your plans for handle material?
 
Hesparus said:
That's big! I'm excited to see it when it's finished. It kind of looks like it's only ground on one side — is this right?

- Chris
Click to expand...

It is evenly ground, except the plunge line gets evenly blended into the ricasso so that it's invisible when finished and hand sanded.
 
Shawn fu said:
Looks great David-interesting hamon on this one...What are your plans for handle material?
Click to expand...

The customer specifically asked for lilac wood which I eventually sourced but it's a bit thin for a chefs knife. I either will need to add spacer material or go with something else. If its not lilac, it must be sourced from NH which makes it harder, so I'm still looking, haha! I'd love to throw some ironwood on this one but it's not my choice :)
 
"While I've been making knives for years, this is my first real attempt at a kitchen knife. I've come to realize that the thin stock and ultra-thin grinds are quite a challenge and pose a new set of obstacles that I didn't encounter making traditional bowies, fixed blades or folders."
Click to expand...

That's very well put. I found the same during the couple big hamon chefs I've done so far. I had worse warping problems than you, I ground my edge too thin before HT. I've come to realize that they should be worked down with a full flat to about .030, then after HT carefully convexed down to super thin.

I also found that this stuff tended to bend while grinding past a certain thinness. AEB-L was the worst for that I've tried though, it was ridiculous.

Nice work! I bet it'll be beautiful when finished. And a mean cutter. Thanks for the WIP. Nice to see someone else noting similar challenges going into big thin knives.
 
David Schott said:
The customer specifically asked for lilac wood which I eventually sourced but it's a bit thin for a chefs knife. I either will need to add spacer material or go with something else. If its not lilac, it must be sourced from NH which makes it harder, so I'm still looking, haha! I'd love to throw some ironwood on this one but it's not my choice :)
Click to expand...

Remember,"It's easier to beg for forgiveness than ask for permission":D
Ironwood would look amazing on this one.
 
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that looks great! and I love the hamon.

on really thin blades, Ive had the best luck just starting bevels, then hardening, and taking my time grinding the heat treated blade to finsihed bevels, as then the steel is much stiffer and less likely to bend during grinding
 
Looking really good! When i do my kitchen knives, i grind everything post HT. You really have no issues losing a hamon in stock that thin, and it really takes away any warping issues. Just a lot more dipping in the bucket.
 
Hello!

I thought i'd update this with the last two sets of pics as this knife is now complete! Without further ado:

Wood selected was stabilized maple burl. Here are a few pics of the skeletonized handle against the wood:
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Here's a better picture of the grain...should look nice!
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I then started on the bolsters. I am using pretty thick material as the handle slabs will be thicker than a normal knife. Rough cut:
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Holes drilled and positioned:
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I then began "carving" the bolsters with a small wheel attachment. This forward curve on the bolsters is a bit of a signnature of mine. I'd say about 75% of my knives feature something like it:
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Polished up a bit more:
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I then peened the bolsters to the blade, which was an uneventful process. The bolsters themselves were coated with JB Weld to make a seal since this is a carbon steel knife that will see kitchen work.

I then roughed up the handles. Here's where that left me:
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Glue-up! THis is always the messiest part:
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After taking the excess epoxy off:
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From here on out, things get easier but more tedious....sanding sanding sanding! Here it is partially completed:
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Next post will have the final pics!
 
Final sanding and polishing was not too bad...I decided to go almost mirror on the bolsters and took the ahndles to a mirror polish but then backed down to 1200 as it felt a bit too slippery.

Here are the final pics. 16" OAL so this is not a small knife by any means!

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This knife will ship out to its owner tomorrow once I get it packaged up!
 
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