Let's Get Into Sharpening
Moderator: Dux
Re: Let's Get Into Sharpening
I just made a video using an India Stone and a well used sharpening rod/steel to get a crappy knife from very dull to easy slicing on magazine paper. I'll try to upload it soon. Took ~4 minutes total. I'll try to upload it later tonight.
A little troubleshooting and common questions:
Question 1: Why does it seem like my edges fail so quickly?
Answer: A few things.
1) You're slamming the edge into ceramic cutting boards, ceramic plates, other cutlery, using the knife to scrape pots out etc... Basically all things that will dull any knife in a fairly rapid manner.
Don't do that, and use the knife to do what it's designed to do, and you'll be surprised how much longer your knives can go without needing a full sharpening.
2) You're not removing the burr fully. The burr, when it's aligned off the edge of your blade, can still do some impressive cutting, may shave hair, and will give the impression the knife itself is sharp. The thing is, that burr is weak, and it is often small enough that you can't see it with the naked eye.
You need to go back and try to remove the burr. Maybe take a few passes on a finer stone, then try this:
- Raise the spine of your knife so that your angle roughly doubles. If you're at 15 degrees or so, you should be in the 30-35 degree range now.
- Take a very light pass into the stone with the side holding the burr angled down and into the stone. Repeat on the other side, where the burr has not likely flipped. The pressure should be less than the knife in most cases.
- Return to your normal sharpening angle, and take 5 or so very light passes on each side, then test for sharpness.
Using high angled passes isn't my idea, but it's become my favorite approach lately.
3) You're using the knife for cutting tasks, but they're still too tough on given the steel, edge geometry etc. Example: a thinly ground knife meant for fine, detail oriented work isn't likely to hold up well against heavy chopping tasks.
Even if you're using wooden cutting boards, and taking care to protect your knife's edge, it can still be put through more abuse than it's designed for.
Question 2: Why won't my knife shave, cut paper etc?
Answer: Probably a burr in the way, but here's a question or two back: How is your knife performing in the kitchen? Is it slicing tomatoes cleanly, without your having to muscle through and crush all the fruit?
Has it maintained performance for weeks with nothing needed other than a few passes on a fine stone? If so, don't worry about it.
Question 3: What if I chipped my knife?
Answer: How deep is the chip? If it's deep enough that you may have cracked the thicker portion of the blade, it may be done for. Sucks, but it happens now and then.
If it's a deep chip, but no damage was done to the main stock of the blade, then you can grind it down, thin it back out, and go back to work. It may change the function of the blade a bit, but it'll still have life left in it.
If it's a shallow chip, then you can just sharpen like you normally would and you'll probably be fine. It the chips are still there, but the rest of the edge is clean and sharp, you need to decide if it's getting in the way of the knife's performance. If you just cook at home, you're likely best off leaving the chips in and just letting future them come out as you continue to sharpen in the future.
You can also use a honing steel/rod and run it lightly across each direction. That can sometimes smooth a small chip or nick out, even though it won't remove it.
Question 4: Should I try to shave with my knife?
Answer: No. Slice newsprint or something if you want to show how sharp it is without cutting a bunch of food.
Question 5: How come my knife felt sharper off my coarse or medium stone(s)?
Answer: I'm guessing you used too much pressure at the finish line.
A couple rules of thumb:
1) Your knife should be sharp off of your coarsest stone. It should be capable of cutting easily, even if the cut itself is a bit rough. If you don't have a cutting edge at your lowest grit, you're not going to help yourself as you progress to a finer finish.
2) More pressure should be used when you have to grind more metal. Less pressure should be used when you're just putting a polish, weakening burrs, microbeveling etc.
3) Too much pressure can result in rolled/crushed edges. Lighten up dramatically at the end and see how you do.
A little troubleshooting and common questions:
Question 1: Why does it seem like my edges fail so quickly?
Answer: A few things.
1) You're slamming the edge into ceramic cutting boards, ceramic plates, other cutlery, using the knife to scrape pots out etc... Basically all things that will dull any knife in a fairly rapid manner.
Don't do that, and use the knife to do what it's designed to do, and you'll be surprised how much longer your knives can go without needing a full sharpening.
2) You're not removing the burr fully. The burr, when it's aligned off the edge of your blade, can still do some impressive cutting, may shave hair, and will give the impression the knife itself is sharp. The thing is, that burr is weak, and it is often small enough that you can't see it with the naked eye.
You need to go back and try to remove the burr. Maybe take a few passes on a finer stone, then try this:
- Raise the spine of your knife so that your angle roughly doubles. If you're at 15 degrees or so, you should be in the 30-35 degree range now.
- Take a very light pass into the stone with the side holding the burr angled down and into the stone. Repeat on the other side, where the burr has not likely flipped. The pressure should be less than the knife in most cases.
- Return to your normal sharpening angle, and take 5 or so very light passes on each side, then test for sharpness.
Using high angled passes isn't my idea, but it's become my favorite approach lately.
3) You're using the knife for cutting tasks, but they're still too tough on given the steel, edge geometry etc. Example: a thinly ground knife meant for fine, detail oriented work isn't likely to hold up well against heavy chopping tasks.
Even if you're using wooden cutting boards, and taking care to protect your knife's edge, it can still be put through more abuse than it's designed for.
Question 2: Why won't my knife shave, cut paper etc?
Answer: Probably a burr in the way, but here's a question or two back: How is your knife performing in the kitchen? Is it slicing tomatoes cleanly, without your having to muscle through and crush all the fruit?
Has it maintained performance for weeks with nothing needed other than a few passes on a fine stone? If so, don't worry about it.
Question 3: What if I chipped my knife?
Answer: How deep is the chip? If it's deep enough that you may have cracked the thicker portion of the blade, it may be done for. Sucks, but it happens now and then.
If it's a deep chip, but no damage was done to the main stock of the blade, then you can grind it down, thin it back out, and go back to work. It may change the function of the blade a bit, but it'll still have life left in it.
If it's a shallow chip, then you can just sharpen like you normally would and you'll probably be fine. It the chips are still there, but the rest of the edge is clean and sharp, you need to decide if it's getting in the way of the knife's performance. If you just cook at home, you're likely best off leaving the chips in and just letting future them come out as you continue to sharpen in the future.
You can also use a honing steel/rod and run it lightly across each direction. That can sometimes smooth a small chip or nick out, even though it won't remove it.
Question 4: Should I try to shave with my knife?
Answer: No. Slice newsprint or something if you want to show how sharp it is without cutting a bunch of food.
Question 5: How come my knife felt sharper off my coarse or medium stone(s)?
Answer: I'm guessing you used too much pressure at the finish line.
A couple rules of thumb:
1) Your knife should be sharp off of your coarsest stone. It should be capable of cutting easily, even if the cut itself is a bit rough. If you don't have a cutting edge at your lowest grit, you're not going to help yourself as you progress to a finer finish.
2) More pressure should be used when you have to grind more metal. Less pressure should be used when you're just putting a polish, weakening burrs, microbeveling etc.
3) Too much pressure can result in rolled/crushed edges. Lighten up dramatically at the end and see how you do.
"Gentle in what you do, Firm in how you do it"
- Buck Brannaman
- Buck Brannaman