Tuesday, January 19, 2010

How to Sharpen a Knife


My uncle gave me a knife and a Sun Tiger waterstone for Christmas about 12 years ago. The best part of the gift was the instructions. I came across this piece of paper with one hand drawn illustration while looking for back-up paperwork for my passport. I thought I should retype it so I can find it easily from now on. He printed it on an ink jet printer. I must have been looking at them while I sharpened the knife because the paper is splashed and the ink has run.

How to Sharpen a Knife:
by Robb White

The knife is already sharp so you will have to use it until it is dull first. That Sun Tiger will do the job. It is a waterstone. Be very careful not to let any grease get on it or it will make a sad place that will never work right again. Wet it good in the sink. It is sort of soft and delicate so don't hit anything with it and don't let it sit on anything rough while you are sharpening because if it gets notched it won't work good. It is best to put the rock on some newspaper while you are sharpening and you need some little water to sprinkle on there every now and then. I do it on the partition of the sink and let a little dribble of water from the spigot drip on there. Sharpen the knife by rubbing it on the light colored side, cutting edge first, alternating sides. Try to hold it at the same angle that the blade is already sharpened at. Try to keep the edge of the blade perpendicular to the direction of the stroke. You'll have to rotate your wrist sort of fancy to do that with the point of the knife to keep the little place that is touching the stone moving right but the sharpness of the point is very important. Be careful not to groove the soft stone by rubbing the same place with the point too long. Though you will have to slice across the stone with the blade so the whole thing will get sharpened, don't saw back and forth. What makes the knife cut is those little scratches perpendicular to the edge, not scratches parallel to it. While you are on the light colored side it ain't important to do anything but grind the blade down so that whatever ruination you did to to the knife by cutting on plates and sinks and all is removed and the original bevel is restored all the way back to the edge. The way you can tell when that happens is by feeling to see if the whole edge is snaggledy and dangerous feeling. If it ain't, keep sharpening. That's the most common mistake, stopping before you get through. It will have a uniformly ground dull steel look to it where you ground the whole blade flat on both sides. After you do the light colored side of the rock right, the knife has a ragged little filament of metal (wire edge) sticking proud of the real edge of the steel. That will cut the hell out of you or a tomato but not much of anything else because it won't stand up -- just bend over and quit cutting. It is alright to grind too long and put too much of a wire edge on there but that just wears the knife out sooner. The best thing to do is grind just exactly enough to get just a hint of wire along the edge but the objective to start with is to get it sharp. Economy of steel ain't important right now.

After you have a wire edge all along the blade it is time to rinse the knife and the rock and do the other side. Better rinse all the sand and little pieces of steel down the sink good or it will rust and stain up the outfit. The dark colored side of the stone is much finer than the light side and will put the perfect edge on there for meat and vegetables. The knife itself is a flexible boning knife and is too fine for rough work like cutting wood and bones. It would be a fine fillet knife and could easily handle the ribs of the fish but it would notch the acute edge to cut his head off.

You do the same thing with the dark side as you did on the light side but don't press down quite as hard and you need to alternate sides of the blade with every stroke. The wire edge will come off as you do this and you need to rinse the little slivers of steel of the stone so the knife won't have to hop over them. I have to get my sharp-nose glasses so I can see what I'm doing. When the wire edge is all gone and all the rough scratches from the rough side of the rock are polished off it is time to quit. To expedite that, at the very last, pick the back of the blade up off the stone a little bit and lightly, carefully, stroke just a hint of a secondary bevel right along the edge.

The way it ought to look is the whole blade will be uniformly smooth with a new polish all the way from the edge to the back of the blade except for the little place back near the handle where the original factory finish remains. The knife will be just as sharp as it was when you got it. (That's a genuine Dexter knife like in every butcher shop in the country. Come sharp from the factory, be careful.) When it gets dull you don't have to sharpen the whole side like the first time but just a little secondary bevel about an eighth inch wide all along the cutting edge. Unless you have really dulled the blade cutting ceramics and stainless steel, the dark side of the rock will be fine for this little touch up job. It won't be quite as acute as the original edge but will cut fine and will actually hold up better if you accidentally hit a bone. (An obtuse edged butcher knife is what you need around a bone or for a fish head.) If you can manage not to rock the blade on the stone too much and round off the edge you can do that a bunch of times before the edge gets too thick and obtuse to cut tomatoes, bone meat and slice roasts.

The blade will try to rust for a while and it needs to do that so that the rusting will form a dark coating that you can treat with camellia seed oil to protect the blade. If you use the knife all the time (which I bet you will do if you have evan a remaining grain of the good sense you were born with) all you will have to do is wash it and keep it dry. Rub the rust off with a paper towel and if it gets too bad, a little hint of steel wool but don't hit the edge or the steel wool will dull your knife. Pretty soon the blade will get sort of gray looking and quit rusting.

It takes a while to learn the feel of the thing. It wouldn't hurt to start off with another knife. This Dexter ain't too precious to use though. About $17 from
Memphis Net and Twine. You will find that stone will wear down pretty quick (that's what makes them work so good) but it ain't too precious to use either. About the same money from Highland Hardware in Atlanta (This is the 250/1000 grit combination waterstone.) There is one odd thing about the stone. Don't let it freeze or it will bust all to pieces because once you wet it it will stay wet down inside.


5 comments:

  1. Happy Birthday to Harry today. Hope he already knows how to use a waterstone, but maybe he didn't know where to get Dexter knives.

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  2. Wow, incredible blog layout! How long have you been blogging for? you make blogging look easy. The overall look of your web site is wonderful, let alone the content!
    Edge hardened rule

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  3. This comment has been removed by the author.

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    Replies
    1. Nice gift Robb White. I also write about knife sharpen tricks. you can find here:
      Knife sharpen tricks

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