How to sharpen a head knife

[Pelallito]

Hello,

I just came across this and enjoyed reading it. Yesterday I came across the paper wheels and will probably order soon. How thick should the blade be for a convex edge? I measured a current head knife and it was 1/16Th thick. So I bought some 1/16 X 4" O1 and I am in the process of sharpening the knife I made with it. I am wondering if I should have gotten something thicker.

I hope that this is a good place to post this and that I am not hijacking the thread. I am going to copy that 4 sided strop soon.

Thanks for the great information.

Regards,

Fred

[Rawhide]

Hi Fred,

I have never measured my head knives, but I'll tell you that I prefer the thinner blades. I don't have a technical reason for such, but I just prefer it, I think it cuts easier. The 4 sided strop is an eye catcher among leatherworkers, and I stole that idea from Peter Main. It is highly functional and I don't know how I got along without it.

[Pelallito]

Hi Marlon,

Sorry to take so long to reply. I just noticed that there was another entry to this thread and read it.

I made the knife, but my heat treating was off. One point cut leather like butter, the other was no good. I took it apart and will reheat treat it.

Thanks for the answer and the help.

Fred

Hi Fred,

I have never measured my head knives, but I'll tell you that I prefer the thinner blades. I don't have a technical reason for such, but I just prefer it, I think it cuts easier. The 4 sided strop is an eye catcher among leatherworkers, and I stole that idea from Peter Main. It is highly functional and I don't know how I got along without it.

[Pablo27]

Great tutorial thanks Rawhide, and I love all the other comments too. So much to learn here. I have had trouble figuring out the correct angle also, what worked for me was to take a protractor and cut an 18 degree angle piece of poster board the hold it between the stone and my knife to check the angle and get used to holding the right angle. It just takes a lot of practice to get it right and get comfortable with the process. I spent hours and hours just sharpening head knifes. Love these forums.

Paul

[Claykan]

This works for me, so thought I'd pass it on. Not to say that it's better than what has already been posted, just another angle to look at.

First off, I run a black Magic Marker along both sides of the edge. This allows you to easily see if the angle you are trying for stays constant.

Then I use a Lansky sharpening system for sharpening my cutting edges. This goes for regular knives and round knives, but we're talking round knives here. You can set the Lansky system for 17, 20, 25 or 30 degrees. I prefer 17 degrees for my round knives since they are only used to cut soft material, and I like them sharp.

The system I purchased comes with 5 stones ranging from 70 to 1,000 grit. I think there is also a 3 stone set you can purchase.

Basically you attached the guide, which has slots for the 4 different cutting angles, to the blade. Then you select the stone you want to use, depending on the condition of your edge. Each stone has a steel rod attached to it. The rod is inserted through one of the slots on the guide, which will keep the angle of the stone constant, and then start working the stone across the blade.

A word of caution! You will be moving the stone against a very sharp and wide blade. Be aware of where your fingers are. I have sharpened my round knives with this system for about 15 years now and can still count to 10. Just pay attention, as you can get the blade to be Scary Sharp!

I haven't looked, but I'm sure that by now there are "You Tube" videos out there where you can watch the system in action, although I doubt it will show round knives being sharpened. If you have any questions let me know.

Fred

.

[Troy Burch]

Fred, I've been wanting an excuse to buy that, so I guess I will now. Will it sharpen a swivel knife blade or a skiver knife thats beveled on only one side? Is it the deluxe 5 stone system 49.99? Thanks Troy

[Claykan]

Fred, I've been wanting an excuse to buy that, so I guess I will now. Will it sharpen a swivel knife blade or a skiver knife thats beveled on only one side? Is it the deluxe 5 stone system 49.99? Thanks Troy

Hi Troy - In answer to your questions:

No, it will not sharpen a swivel knife blade. The blade is just too small to work with. The good news is, if you don't drop or otherwise damage your swivel knife blade, all it should need is stropping. If needed, there are special guides made just for swivel knife blades, which can be purchased through a leathercraft supplier.

Sharpening a knife with the blade beveled on just one side is no problem. But since the system is designed to work with knives that have the blade edge running along the long side of the blade, I think you'll have to use a bench stone for a skiver.

I just looked at Lansky's webpage and wow, they have really added to their products. A lot more to pick from now. The Deluxe 5 stone system for $49.99 is the one I have, but it may not be right for you.

If you're going to be using it to maintain blades that you buy new, the 3 stone system is all you need.

If, like me, you buy some used knives, then probably the 5 stone system is the way to go. I bought some great, 100 year old C.S. Osborne head and round knives off of ebay. Great steel, but over the years the blade edges were in terrible shape and it took all five stones to make them right. But brother, do they slice through the leather.

Lastly, if you plan to sharpen knives for others, or your work load is such that you'll be using the system weekly, then you might think about getting one of the higher grade systems.

Let me know if you have any other questions.

Fred

[Troy Burch]

Hey Fred, I bought a few things from Lansky's today, thanks for the advice.

[Claykan]

Hey Fred, I bought a few things from Lansky's today, thanks for the advice.

Good deal. Let me know if you have any questions. Especially when it comes to a head knife or round knife. You should only do half the blade at a time. I'll explain in detail if you plan to sharpen one of those. Really simple when you set it up correctly.

Fred

[simontuntelder]

I've become sufficient at sharpening and honing, but I'm still at a beginners level. I don't have that many problems keeping the knife in the same angle and I can quite easily get my knives sharp enough to go through 6mm veg tan.

However I'm using DMT diamond stones, which are fairly aggressive and when I go from the 1200-ish grit to honing on the strop, I find that I need something with a higher grit, as it's very hard removing some of the small scratches.

What would be a good grit number for the step after 1200 but before stropping?

And can you recommend a specific stone/brand etc.

Ps I know that DMT offers a 8000 grit and I would like to purchase that one, but it's very expensive in Europe.

[Colt W Knight]

I've become sufficient at sharpening and honing, but I'm still at a beginners level. I don't have that many problems keeping the knife in the same angle and I can quite easily get my knives sharp enough to go through 6mm veg tan.

However I'm using DMT diamond stones, which are fairly aggressive and when I go from the 1200-ish grit to honing on the strop, I find that I need something with a higher grit, as it's very hard removing some of the small scratches.

What would be a good grit number for the step after 1200 but before stropping?

And can you recommend a specific stone/brand etc.

Ps I know that DMT offers a 8000 grit and I would like to purchase that one, but it's very expensive in Europe.

I do all my sharpening on DMT DiaSharp Stones, but I have Extra coarse, coarse, fine, and extra fine. If you don't do much sharpening, you can buy some automotive wet sanding paper for polishing paint, and lay it on some plate glass or your tooling marble to save some money.

[Mudruck]

I do all my sharpening on DMT DiaSharp Stones, but I have Extra coarse, coarse, fine, and extra fine. If you don't do much sharpening, you can buy some automotive wet sanding paper for polishing paint, and lay it on some plate glass or your tooling marble to save some money.

This is what I have moved to when I sharpen. With 2000 and 3000 grit wet dry on my slab, I can get a nice sharp edge and do touch ups if I need to on a blade.

[Pablo27]

I had a lot of trouble getting my head knifes sharp until I bought a Video called "Use & Care of Hand Tools" by Andy Stasiak. It shows in detail how to sharpen ALL you leather knives and tools. It really helps me when I can actually see someone doing the chore. Don't remember where I bought it but you can google it and find it, The best $20 I ever spent. Just sayin.....

Paul

[hornm]

I've become sufficient at sharpening and honing, but I'm still at a beginners level. I don't have that many problems keeping the knife in the same angle and I can quite easily get my knives sharp enough to go through 6mm veg tan.

However I'm using DMT diamond stones, which are fairly aggressive and when I go from the 1200-ish grit to honing on the strop, I find that I need something with a higher grit, as it's very hard removing some of the small scratches.

What would be a good grit number for the step after 1200 but before stropping?

And can you recommend a specific stone/brand etc.

Ps I know that DMT offers a 8000 grit and I would like to purchase that one, but it's very expensive in Europe.

You could find another brand of diamond hone or just find a synthetic or nautral wetstone. If you go to the synthetic/natural then then go for something like a 4000/8000 combo.The only real advantage to the DMT is that they are fast cutting and won't dish out on you. but for most of the steels used any of the previously mentioned natural or synthetic will do the job. If you are working with the blades from Paul / Leather Wranglers then you'd want to lean more on the diamond stones.

After all that.. you'd still want to go to some sort of finisher though to put a silky smooth final polish at the edge..

I'll stop with that before my OCD tendencies kick in.

Horn

Edited August 13, 2014 by hornm

[rawcustom]

Diamonds are great for moving material fast, but I doubt you would really need one for maintaining a head knife. I prefer diamonds in the coarse grits, but switch to Spyderco synthetic stones for the final steps before a strop. Not sure availability of them in Europe, but I would think you have some choices of maybe different brands. The method mentioned above using sandpaper is a inexpensive and effective solution. Plus you may use it to find what grit you are really in search of, i.e., if 2000 grit is removing the scratches and making your edges more strop ready, then you don't need to overshoot the fine grit on your stone or diamond.

[bikermutt07]

On 3/14/2008 at 9:58 AM, Art said:

Hi Sharp,

The old Convex -- hollow ground -- straight bevel controversy again? Been there done that on the knife-list 10 or more years ago. Convex is great, I like meat behind my edge. However, that is not an easy edge for the average leatherworker to profile, and the newer head knives are getting thinner and thinner to the point that the Convex is getting darned near impossible, not quite, but darned near. While you and I probably have a Bader or a Burr-King where you can get a long run of belt to effectively produce the edge (although the Japanese used to do it with a rock) the average leatherworker doesn't and the hollow or straight is much easier with readily available tools, and very easy to maintain. I do agree that convex is better if you have a thick enough blade to pull it off, the J.Cook blades would be candidates for a convex edge, and even the CSO blades could be done to effect. The last .030-.060 of most convex edges are straight bevels anyway.

Art

Art. I'm a complete novice when it comes to sharpening. But I find the convex easier to maintain on my knives. Two years ago I watched a gazillion videos on sharpening. I just thought as a man, dangit, I should be able to sharpen a knife somehow someway.

It was really frustrating. The first video that stuck out was some kid with a cheap buck lockblade. That kid took a cinder block, a red brick, and a little water and had hairs jumping off his arm in a matter of minutes.

The second video was of a gentleman in Canada that sells fallkniven knives. One comment in the video went like this.....

The first time "you" sharpen a knife it will take longer than normal. Your hand does certain little things that other peoples hands and machines don't do. 

What he was saying was that all my life I had given up on sharpening too quickly. I didn't take the time to acclimate the blade to "my" sharpening.

That was a huge eyeopener for me. Since then I have been able to get my knives working sharp. Not sharp like you can accomplish, but sharp enough for my needs. 

I tend to lean more towards the sand paper mouse pad sharpening technique. I lay the blade flat and as I start to pull the blade across the paper I lift it up until I feel the edge grabbing the paper. This sets my angle. And it may not be right but it works for me.

Then comes leather. I had to raise the bar. In the last two weeks I have finally been able to get my leather tools just about as sharp as they need to be.

I have since abandoned the mouse pad and replaced it do The a piece of quartz (manmade granite) about 8x12.  This has helped me get my edges cleaner.

Two weeks ago I acquired a small Al Stohlman round knife. It was kind of sharp, but I hadn't played with it.

Thirty minutes ago I read through this tutorial. I have never sharpened a round knife. The whole time I was sharpening it I was thinking "Boy am I messing this thing up".

After stropping it, it cut a piece of Hermann Oak four ounce like it was paper. The I took it to some 8 ounce scrap. I can actually hold the piece up in the air and slice right through it. I was amazed. 

Now this is an Al Stohlman knife and I have heard bad things about those here. So, I don't know how easily it will keep that edge. But it's nice to think I can get it that sharp again.

I'm quite proud of myself.

[Art]

On 10/18/2016 at 2:46 PM, bikermutt07 said:

Art. I'm a complete novice when it comes to sharpening. But I find the convex easier to maintain on my knives. Two years ago I watched a gazillion videos on sharpening. I just thought as a man, dangit, I should be able to sharpen a knife somehow someway.

It was really frustrating. The first video that stuck out was some kid with a cheap buck lockblade. That kid took a cinder block, a red brick, and a little water and had hairs jumping off his arm in a matter of minutes.

The second video was of a gentleman in Canada that sells fallkniven knives. One comment in the video went like this.....

The first time "you" sharpen a knife it will take longer than normal. Your hand does certain little things that other peoples hands and machines don't do. 

What he was saying was that all my life I had given up on sharpening too quickly. I didn't take the time to acclimate the blade to "my" sharpening.

That was a huge eyeopener for me. Since then I have been able to get my knives working sharp. Not sharp like you can accomplish, but sharp enough for my needs. 

I tend to lean more towards the sand paper mouse pad sharpening technique. I lay the blade flat and as I start to pull the blade across the paper I lift it up until I feel the edge grabbing the paper. This sets my angle. And it may not be right but it works for me.

Then comes leather. I had to raise the bar. In the last two weeks I have finally been able to get my leather tools just about as sharp as they need to be.

I have since abandoned the mouse pad and replaced it do The a piece of quartz (manmade granite) about 8x12.  This has helped me get my edges cleaner.

Two weeks ago I acquired a small Al Stohlman round knife. It was kind of sharp, but I hadn't played with it.

Thirty minutes ago I read through this tutorial. I have never sharpened a round knife. The whole time I was sharpening it I was thinking "Boy am I messing this thing up".

After stropping it, it cut a piece of Hermann Oak four ounce like it was paper. The I took it to some 8 ounce scrap. I can actually hold the piece up in the air and slice right through it. I was amazed. 

Now this is an Al Stohlman knife and I have heard bad things about those here. So, I don't know how easily it will keep that edge. But it's nice to think I can get it that sharp again.

I'm quite proud of myself.

Well, I'm quite proud of yourself too.  If you can sharpen a head knife to that degree, to the point that it satisfies you, you have arrived.

Art

[bikermutt07]

Thanks.

[TinkerTailor]

There is one thing about hand sharpening that has not been mentioned (enough) is the pressure you use and when. There are 2 ways to control material removal, pressure and grit. Either a lesser grit or a lighter pressure will create a finer grind. Guys who do surface grinding and sharpening on machines get mirror finishes with crazy coarse stones just by varying the pressure. (if you are interested in this: https://www.youtube.com/user/shadonhkw/videos)

The particles sharpening stones are made of have sharp corners, and this is what does the cutting. When sharpening, the pressure that you use dictates how far the little corners dig in. More pressure=deeper scratches. Less pressure= shallower.

I look at it as a system of define-refine-finish. 

When starting out with a dull tool, heavily removing material,  and I am defining the angle and geometry, I use lots of pressure. I want maximum digging from the particles. I want to feel vibrations of the metal coming off through my fingers. This is the define stage

As I get closer to shape, I switch to a medium pressure. I call this refining stage. This keeps the particles from digging in as far. Less material is removed and the scratches are shallower. I am perfecting the geometry and bringing the surfaces smooth, clean, and ready for a polish. I also put in secondary bevels at this stage and get it to a reasonably sharp edge. This is the same effect as going up in grit. In addition, the particles in your slurry will break down smaller over time as you sharpen, adding to the effect.

The final stone step for me is the finishing stage, where I polish and sharpen the blade. In this step, very little pressure is used. The blade is floating on the slurry and you can just hear it touch the stone.

From there I have a strop stick loaded with some random white rouge I have a bunch of. I think it came in old Tandy kits. I vary the pressure here the same way.  I strop it till its awesome and then a couple times more and also before each session, sometimes during.

I do this all on the same stone. My grumpy-gramps taught me about pressure on an old Norton. This is how guys can use a brick to make a sharp edge. Pressure control. Angle is one thing, pressure control is the real skill for the expert sharpener. This way is fast once you get good because you are not wasting time switching stones, and removing material unnecessarily slow due to following arbitrary steps.

Now the downfall, and the reason why guys use 5 grit sharpening systems: One screw up at the later stages puts you right back at the beginning. One stroke too hard or with the wrong angle and you go back to start. It is pretty hard to put deep scratches, and have to start again, if you are on a 2000 grit diamond stone.

If you are new  to sharpening and don't know what 20 degrees looks like, get a few grits of stones and work up. As you get better with the pressure control, start to take away stones in the sequence. The reality is, in practice, it is a gradual reduction in pressure not 3 steps. The steps are a mental trick to "Pace the pressure". Also, pressure will need to be adjusted for harder and softer steels. This is also an experience thing. You get a feel for it.

Edited October 20, 2016 by TinkerTailor

[gmace99]

 

 

 

[Bobby hdflame]

Good explanation Rawhide!

I realize some people have problems maintaining the correct angle.  I don't really need or use it anymore, but here's an excellent manual sharpener that's also affordable.  I used one for years.  It is easy to maintain the correct angle and with just a little practice anyone can put a perfect shaving edge on anything from a small paring knife to a machete!  Guys at the fire station would line up with their pocket knives when I brought it out to sharpen mine!  It got to the point that I had to go into hiding when sharpening mine to keep from sharpening everybody's knives.

When I first bought my round knife it was not as sharp as I wanted, so I used this sharpener to put the initial edge on it.  Since then, all I need to do is strop it on leather with some fine rouge.  If you have a buffing wheel with some rouge, it's quick and easy to keep it sharp.

When using it, start with the coarse stone until you get the same angle from one end to the other.  Then gradually work your way down to the finest stone to get a polished razor edge.  If you use it to maintain your round knife you'll only need to use the finest stone to bring it back.  The secret is after every few cuts, strop the edge on leather with some rouge.  Maintaining a perfect good cutting edge on your round knife is a constant thing WHILE YOU'RE USING IT!

https://www.amazon.com/Lansky-Professional-Sharpening-System-Serrated/dp/B001KN3OKO/ref=sr_1_3?ie=UTF8&qid=1487792044&sr=8-3&keywords=lansky+knife+sharpener

https://www.youtube.com/results?search_query=Lansky+Professional+Sharpening+System 

BTW, I bought a sapphire and a diamond stone for mine.  I use them after using the fine stone that comes with the basic kits.

 

Hope this helps.

Edited February 22, 2017 by Bobby hdflame

[Sangrati]

On 3/12/2008 at 6:56 AM, Rawhide said:

To all:

I have had several requests to explain how I sharpen my head knives. I am by far not an expert, but here is how I do it, and it works for me. There was a thread where I addressed this before the crash of 07.

Below is a link to the tutorial that most gracious Johanna has created.

Please feel free to contact me if you have questions. I hope this is something useful.

Tool on!

Marlon

How to sharpen a head knife

The link is not working.

Regards

Sangrati

[Northmount]

8 hours ago, Sangrati said:

The link is not working.

Regards

Sangrati

LWN has changed to a secure webserver so all previous URLs that were http://leatherworker.net ... etc. now need to be https://leatherworker.net ... etc.

So the URL becomes https://leatherworker.net/sharpenheadknife.htm

Tom

 

[Sangrati]

1 hour ago, Northmount said:

LWN has changed to a secure webserver so all previous URLs that were http://leatherworker.net ... etc. now need to be https://leatherworker.net ... etc.

So the URL becomes https://leatherworker.net/sharpenheadknife.htm

Tom

 

Thanks. Got it.

Regards

 

[hiloper]

On 3/13/2008 at 12:28 PM, cjbleather said:

Marion, Off hand or easily available to you, what is the tan of 20 degrees? Thanks Carlb

PS I haven't found my engineering formula/table book yet. I can't even remember what we used to call this book as we went through school. yach for my memory.

Peter"s Book