Butchers knife for a friend - WIP

[Cushing H.]

Clamp the thin material between two pieces of scrap wood when drilling the hole. Or use a step drill. Or glue your material down to some scrap with CA glue, drill the hole, then release it with acetone. Twist drills, especially large ones, are terrible at drilling thin materials so you have to help them out by supporting the workpiece properly. Just putting it on top of a piece of scrap isn’t enough to get a clean hole.

So I found out :-(. Thank you for the ideas!

 

[Stacy E. Apelt - Bladesmith]

I think it came out well.

The issue with the "clouds" all but being ground off is what I was talking about in the layering method. On the next one heavily hammer work the cloud area and then grind it flat again. This will give a more cloudlike (random) look.

 

[weo]

Thanks, Stacy. I understand what you meant by layering and heavy hammering. I'll post pics on the next one.

I'm almost ready to send it off, but I'd like a bit more advice on if I should. I'm afraid I made the blade a little too thin at the edge, so I did a bit of testing today, chopping up a whole chicken and abusing the blade a little (I think) by chopping through the thigh bones, the breasts, and torquing the blade on the cutting board a little bit while popping the joints open with the tip. The edge seemed to hold up pretty well, was still shaving hairs off my arm after cleaning, but there are 2 spots where the edge deflected a little as shown in the pics. The yellow circle is the same spot on opposite sides of the blade.

It's my understanding that this is what butchers use a steel for, but are deflections like this the acceptable norm when chopping through bones? Should I send this off for him to use? My plan if I do is to ask him to let me know if he wants a heavier blade edge and I will make him another one. This is a gift, so he's not paying me for it, but I don't want to send off something that isn't suited for it's purpose.
Thanks.

 

[Cushing H.]

Omg. William, this made me cringe. But ... this is my bias: a knife used to chop through bones is a cleaver, not a slicing knife ... more like a hatchet in edge geometry. Two different kinds of knives with different edge geometries. Question is, does your friend want to chop, or slice... and create the edge geometry to fit that need.

I cringe because I never do any chopping with my knives (though I have seen plenty of restaurants that do) ... and I would not expect the edges of my knives to not be damaged by that kind of use (because I keep them all with pretty low angles). Again, depends on what you want to use the thing for...

 

[Stacy E. Apelt - Bladesmith]

That looks normal considering the abusive treatment of the blade. If you want to prevent it, I would raise the edge angle a couple degrees. A steel is the tool used to refine/restore those type deflections. A pass or two on a fine stone will also restore irt.

You need to decide if it will be a rough use chef's knife that will slice.dice,chop, and bone ... or a cutting use blade for slicing meats and veggies. The edge angle is lower for a slicer.

 

[Cushing H.]

William - sorry .. that last post sounded more like a lecture than I meant it to. I don’t know, maybe a high Rockwell blade with fine edge geometry can be expected to go through bones. I look forward to Stacy’s response.

I think I would still cringe though ... something akin to the fingernails on chalk board thing ...

 

[Stacy E. Apelt - Bladesmith]

In modern knife steels, hardness is usually not the cause of a failure if the blade was properly hardened and tempered. The old days we made them Rc 55-58 for fear of the blades breaking and chipping. Now we know how to harden and temper a blade to Rc 62 with no issues at all. The place where a blade fails or succeeds is geometry. The bevel shape, blade thickness, edge thickness, and edge angle will determine most of why the knife does its task or not. If I was to pick one of those that made the most difference is would be edge angle.

 

[Cushing H.]

Stacy I guess that is exactly what I am asking. Ordinarily (from the old days) I outdone say that a blade with a small angle edge runs a risk of being damaged if used to chop through a chicken bone (I have one example...). With current steel and HT process at say 62 or higher ... does that same risk exist?

if not, why not just make everything HRC 62 or higher, use a small edge angle .... and chop away?

 

[Stacy E. Apelt - Bladesmith]

The steel type determines the limit of hardness. Some steels are best at Rc59/60 and others will tolerate Rc62/63.

As a broad generality, the steels we use for kitchen knives today will most all do well at Rc62/61.
BUT, the task has to be considered first, and then the hardness and geometry applied to that task.

Larin has been a significant contributor to improved knives with his testing, charts, and graphs in the ability to match up toughness, hardness, and edge retention in designing a modern blade

 

[weo]

Good morning, all. I hope everyone is remaining healthy and happy.
Thanks for the replies, they answered my main questions.

That looks normal considering the abusive treatment of the blade.

That's what I was hoping to hear. I was trying to abuse the blade and am hoping that Mike (who, as I mentioned previously, is a professional chef) knows what he's doing and will treat it better.

my bias: a knife used to chop through bones is a cleaver, not a slicing knife

You need to decide if it will be a rough use chef's knife that will slice.dice,chop, and bone ... or a cutting use blade for slicing meats and veggies. The edge angle is lower for a slicer.

I decided to try for a combination of the two, partly because (1) Mike didn't clarify which side of the coin he wanted me to err on, merely stating that he is going to use it to break down turkeys, and that he's never seen a blade like what he wanted me to make; and (2) because I'm used to full flat grinds and veggie slicers.
Like I mentioned above, I'm hoping he will give me honest feedback and let me make him another one with a heavier edge if this doesn't work for him. I'll post a follow up if that's what happens. If not, then I'll assume I got it right.
Again, thanks for all the input over this extended project.

 

[Stacy E. Apelt - Bladesmith]

When in doubt in finishing a kitchen knife, I make the edge for slicing. If the user finds the edge deflects or has micro-chipping because of his use, I recommend/offer resharpening at 3 to 5 degrees higher angle. That has always stopped the issue.

 

[Cushing H.]

Mike didn't clarify which side of the coin he wanted me to err on, merely stating that he is going to use it to break down turkeys,

Maybe weird thought ..... when I break down a bird of any kind, I reach for my slicing knives to get down to the joints, then reach for my boning knife (smaller angle, thicker stock) to wedge my way into the joint and cut the tendons and pop the joint. Rarely do I actually chop through bones.

How about ..... with a follow on knife, you keep a full flat grind from the heel to about 3/4 of the way towards the tip .... then transition to a non-ffg (but not so far as a scandi) towards the tip .... allowing for more rigidity at the tip to push it into those joints and pry it around to pop the joints. Might look weird though .... but might be functional......

 

[weo]

How about ..... with a follow on knife

I'm assuming you meant "follow up knife"...
I'm hoping/planning on there not being one.

But in response to your question/suggestion, I did keep the tip a little heavier. But I'm thinking this is a more complicated solution to a non-existent problem if you just make a thicker blade than one that is a dedicated veggie slicer.

Don't forget, blades will need to be sharpened eventually and if the grind gets too complicated, subsequent maintenance will become difficult, if not impossible to replicate

 

[Cushing H.]

Don't forget, blades will need to be sharpened eventually and if the grind gets too complicated, subsequent maintenance will become difficult, if not impossible to replicate

true .... very true....

 

[A.McPherson]

Now this is something interesting I think... The difference in butchering chickens! So most people I know in our society break down a chicken just like C Cushing H. said.

Anyone ever had fried chicken in Korea? They do not butcher a chicken like we do here! They hack it in half straight down the spine, then turn it 90° and chop it into blocks about 1- 2 inches wide, disregarding bones.

But they don't use thin knives for this. They use something much more akin to a cleaver than a slicer...

 

[Cushing H.]

Now this is something interesting I think... The difference in butchering chickens! So most people I know in our society break down a chicken just like C Cushing H. said.

Anyone ever had fried chicken in Korea? They do not butcher a chicken like we do here! They hack it in half straight down the spine, then turn it 90° and chop it into blocks about 1- 2 inches wide, disregarding bones.

But they don't use thin knives for this. They use something much more akin to a cleaver than a slicer...

Same thing with chinese roast duck. Just a big (usually hollowed out) cutting board, and a big heavy (thick, high angle edge) cleaver. whack, whack .... and you have bite size pieces (but you need to spit out the pieces of bones....). It is actually that very image I had in mind when I wrote "like a hatchet" above - nothing derogatory at all - just a reflection of the fact they wield the thing like a hatchet, not a slicer.

William - I guess it comes back to the question of just what your friend wants to do with this knife. If he wants to use it like A.McPherson says above, then maybe just re-doing the edge to a wider angle (25 degrees???) might do just fine.....

 

[weo]

I guess it comes back to the question of just what your friend wants to do with this knife.

It's in the post office's hands now. Hopefully I'll get some useful feedback sometime in the near future. If I do, I'll try to remember to post it here. (And hopefully I won't be a accused of necroposting....)