How to properly sharpen a chisel grind knife

C

Charlie_K

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Jul 16, 2012
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The local pawn shop had a Victorinox brand knife in today. Gardener, Pruner, Florist, whatever you want to call it, it was $4 after negotiations were done and I got it. The edge needs sharpening. But I don't know how to sharpen a chisel grind knife properly. Can I use a pull through sharpener if I'm careful or do I need something else?
 
Can you post pictures of the blade?

In general on a chisel grind you do all your sharpening on the bevel side, when that is mostly completed you just strop lightly on the unbeveled side to remove the burr. A pull through sharpener will ruin it.
 
A lot depends on the sharpener you are using. In essence, you are going to do what olpappy says. Recommend you go to the Emersom website or YouTube but the easiest way I've found is with my edge pro and only sharpen the bevel side.
Then a quick pass on the crock stick to deburr it.

I put dry erase on the bevel before I sharpen just to make sure I'm getting all the way down to the actual edge. Once you are knocking the dry erase off of the edge, you have the correct angle. I usually go 20 - 30 (light to med pressure) passes and then stop to check for a burr on the non bevel side.

Keep going until you feel a nice even burr on the non bevel side, once there then all you have to do is give it 2-3 passes on the non bevel side (very light pressure) and check to see if its as sharp as you want it. If not, just keep repeating...... Hit the bevel, create a burr then remove burr :)
 
This is a custom dashi that I have. It's been sharpened on both sides and is razor sharp. Not sure what this grind would be considered. A hybrid maybe?

IMAG1738_zpsa2fc891b.jpg


IMAG1737_zps69e0fb4b.jpg


That bevel on the backside is very obtuse, almost just polishing of the steel. It is pretty acute overall though.
 
I believe that is called a chisel grind done wrong!

Many hardcore chisel fans will tell you that you can't sharpen both sides of a chisel grind, but if you leave a nice acute micro bevel on the "back" side you should be fine. The easiest to sharpen a chisel is to lay it on a stone and rock it until you feel the flat edge (if you want to match the existing bevel). This method is easy, but stands a chance of ruining the finish of a knife, so I would only recommend it for users. Other than that the easiest way is to to know what the edge is through experience. All you need to remember is that stropping or a light pass on your stone (preferably with the knife almost flat, you want to get it close to a 0° edge on the back) will remove the burr.

Unless you get chips or horribly neglect the edge, all you should need is stropping on the back side of the edge to touch it right back to sharp.
 
Why is it wrong? I think I may have worded it poorly, or made it confusing. The back side is most just polished steel at the edge. It does have a slight convex to it.

I guess it doesn't matter to me. Different is just different when it's exceedingly sharp, which is never "wrong". ;)
 
^

It's not "wrong". Japanese blades have many different combinations like 50/50 (V grind), 70/30, etc. Yours looks like about 80/20 to me. The Japanese blades also come in real pure chisel grinds and "almost" chisel grinds (different types of Yanagiba that may or may not have a hollow back side and an optional micro bevel on the back).

All of these blades cut and cut well.

I think the conventional wisdom about "don't sharpen the back of a chisel ground blade!!!" comes from two factors:

1. Actual chisels used for woodworking. On these, if you alter the geometry of the flat side by grinding too much, it makes the tool work differently which is "wrong". the flat side of the chisel needs to be flat to work as expected. I'm not very accomplished with wood, but I'm pretty sure this is correct.
2. If you put a micro bevel on the flat side of a chisel ground knife you are increasing the overall edge angle, which makes it less sharp. The smaller the bevel angle, the sharper the blade is. Add 5 degrees to it and it's less sharp. By how much? Well that's really hard to say.

With that in mind, I think making *teeny tiny* micro bevels on chisel ground blades that are NOT woodworking chisels, is essentially unnoticeable. Your 80/20 blade looks like it cuts like a demon! I hope I'm right. :)

Brian.
 
If it works, it works!

Proper chisel have bevel on one side only, lay bevel flat on stone to sharpen, seems easy but requires some practice.

You can microbevel the back but like bgentry said, it will lose performance.
 
Brian, your right. ;) The only thing I wish is that it were a larger knife! :) On the other hand, it was a gift from a great forum member that was creative (and generous) enough that he had it made alongside a custom knife for his collection as a way to do a giveaway for someone that hadn't had a true custom knife.

It's a fine knife that is going to a friend of mine.

As for the grind, I'd call it 90/10 or maybe even 95/5. Hard to tell in those, admittedly bad, pics.
 
Strigamort said:
Why is it wrong? I think I may have worded it poorly, or made it confusing. The back side is most just polished steel at the edge. It does have a slight convex to it.

I guess it doesn't matter to me. Different is just different when it's exceedingly sharp, which is never "wrong". ;)
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I'm just teasing you. The pics do make it look like you put a full on bevel on the back side, though. I do enjoy a good chisel grind (only if the grind is a proper left hand grind like it should be!), and find them to be so bloody easy to sharpen. Lay it on your stone, sharpen normally, then just take the back side on nice and acute on your finest stone.

The thing to take away from all of this is that a chisel grind is awesome, and depending on how it is sharpened very versatile.
 
Haha, fair enough.

I used the knife for carving a little basswood. Does pretty well, although the grind does take some getting use to. Oh, also carved our initials into a park bench in the mountains. Don't worry, the thing had hundreds of carvings in it already. ;)
 
Rat Finkenstein said:
Never use a pull through sharpener on anything for any reason.
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Hey, they work great on knives that have already been ruined on them and will likely never see a proper sharpening. The cheap ceramic Rapala pull through I used before I started proper sharpening worked surprisingly well. Once you corrected the burr left you did get a sharp edge.

Never never ever take a chisel grind through a pull through. Use stone or a belt (or strops) on chisel grinds.
 
Charlie_K said:
You guys are telling me that the ceramic section on one of these http://www.amazon.com/Smiths-PP1-Po...UTF8&qid=1380837945&sr=1-1&keywords=sharpener will ruin the edge of a knife?
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Yes. Avoid carbide sharpeners like the plague. View it like running only NOS instead of gas in a car. It will work, and get your to where you need to go, but it will likely do a ton of damage. There are tons of cheap sharpeners out there that work correctly. Everything from a $20 GATCO clamp all the way to a few hundred dollar Edge Pro or high end sander.
 
dkb45 said:
Yes. Avoid carbide sharpeners like the plague. View it like running only NOS instead of gas in a car. It will work, and get your to where you need to go, but it will likely do a ton of damage. There are tons of cheap sharpeners out there that work correctly. Everything from a $20 GATCO clamp all the way to a few hundred dollar Edge Pro or high end sander.
Click to expand...

I was asking about the ceramic part, not the carbide.
 
You can find a ceramic rob sharpener for just a little more (the ones that look like a butcher's steel). For a few bucks more than that you can get something that has angle guides and ceramic.

Bottom line, the saving are nowhere near worth the reduction of worth.
 
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