How to sharpen a knife

[aliva]

For what its worth I use Japanese water stones. I use a knife guide, from amazon, just clips to the knife blade. Start with 200 grit if the knife needs to get the proper geometry, then a 1000 grit, next is 2000 grit, finally is a 6000 grit. This all works great for me. There are many u tube videos on how to sharpen a knife. Everybody has their own preference, use what works for you. Keep in mind the quality of knife material makes a huge difference. I have a Japanese kitchen knife which is VG 10, one of the best steels out there.

 

[Cobra]

I have only tried using sharpening stones all of my life. My dad could use a sharpening steel. He would even use a piece of concrete at times. I never even thought of using a belt sander until this week. I am using very light pressure and my hand as a guide. My hand is right behind the blade at the belt. I am feeling virtually no heat. Warm at most. I will have at it with another of my dull knives and see how it goes.

At the thin edge of the blade you can very easily surpass the temper point.
I only use slow speed cooled stones or hand diamond hones.

 

[mickri]

I have fiddled with the stone that I have with no success. Before I do any more I am going to get a leather belt for the belt sander. That will be next month. The 3 knives that I sharpened on the belt sander are sharper than they have ever been in the past.

 

[lordbeezer]

Think you said you had a combination stone..if so you need a different grade of stone(s)..getting close to the 50 ..

 

[ch2co]

jwmay said
“Hey finally something I know something about. Written descriptions won’t get you there very quick. It takes a lot of practice. I have hundreds of hours practicing with straight razors. Anyhow, for kitchen knives, I’ve found nothing quicker and easier than this device. It works remarkably well. It worked for me the absolute first time, after watching one YouTube video. I think it’s called a sharpening steel”
———————————————————
Sorry I haven’t been watching this forum close enough and just noticed jw’s entry. I’ve never known much about sharpening knives except when using sharpening steels. I have a couple of sets of 120 ++ year old pearl handled family heirloom Sheffield cutlery which includes “sharpening steels”.


It’s been several years since I’ve carved a turkey with the knives themselves, but I often use one of the sharpeners to sharpen other knives (kitchen, hunting etc.) They sharpen like magic and still work like new after having sharpened many hundreds of knife edges in their long lives. If necessary I will use a grinding wheel to prepaid an edge, but do the final edging with a steel. I have no idea what kind of steel they are made of, ask Sheffield, but for that really sharp edge, they are like magic.
Just the ramblings from:
Chuck the grumpy old guy

 

[Bob Korves]

jwmay said
“Hey finally something I know something about. Written descriptions won’t get you there very quick. It takes a lot of practice. I have hundreds of hours practicing with straight razors. Anyhow, for kitchen knives, I’ve found nothing quicker and easier than this device. It works remarkably well. It worked for me the absolute first time, after watching one YouTube video. I think it’s called a sharpening steel”
———————————————————
Sorry I haven’t been watching this forum close enough and just noticed jw’s entry. I’ve never known much about sharpening knives except when using sharpening steels. I have a couple of sets of 120 ++ year old pearl handled family heirloom Sheffield cutlery which includes “sharpening steels”.


It’s been several years since I’ve carved a turkey with the knives themselves, but I often use one of the sharpeners to sharpen other knives (kitchen, hunting etc.) They sharpen like magic and still work like new after having sharpened many hundreds of knife edges in their long lives. If necessary I will use a grinding wheel to prepaid an edge, but do the final edging with a steel. I have no idea what kind of steel they are made of, ask Sheffield, but for that really sharp edge, they are like magic.
Just the ramblings from:
Chuck the grumpy old guy

A true steel is just smooth and hardened steel and does not sharpen anything. It straightens the cutting edge if it has been bent over. There are also rods called "steels" with grit embedded in them, a totally different animal. If it has grit, you have to be quite careful of the angle of blade to "steel", or you will end up with a chisel edge.

 

[ch2co]

A true steel is just smooth and hardened steel and does not sharpen anything. It straightens the cutting edge if it has been bent over. There are also rods called "steels" with grit embedded in them, a totally different animal. If it has grit, you have to be quite careful of the angle of blade to "steel", or you will end up with a chisel edge.

Yah, Bob, no grit in these “steels”, just VERY fine grooves, there is no removal of material that I can see, even with a microscope. And yes, the angle of attack is almost perfectly parallel with the side of the blade, just a few degrees of tilt. Don’t know what else I can say. The knives are very old and obviously have had a lot of use over the last century plus. Maybe these rods aren’t “steels”, but they don’t seem to remove metal either. If there is metal removal in their use, I can’t see any removed material, even at 100 power magnification.

 

[MarkM]

It s a fine art sharpening. When you consider how thin the edge gets and factor in the heat of that thin edge you have to be very concious of the thinning edge and be careful not to fold that burr over. It will make that edge blunt even though it is hardly visible to the eye.
On my Tormek when I First got the jigs and machine there was a big learning curve. Although there are jigs that are very well designed there is the operator that has to pay attention and understand there is technique. At first I had a tough time honing on the leather wheel until I realized I was doing just this. Folding the burr over. Wether machine or hand grind pay attention to that burr.
I have found the restaurants that use a steel for there knives have changed the angle quite a bit without realizing they have done this. Then one has to remove more material to get back to that angle.
I do most of my knives at 18 degrees and doctor up from there depending on the quality of the steel and if it s a personal knife or for all.
The tormek stones are 220 then can be changed to 1000 with there dressing stone. From there the leather hone and compound will get you 4000.
I have two of there grinding wheels. General purpose and a Wheel for carbides and higher carbon. They have recently come out with Diamond wheels.
I plan on building a machine to use there jigs with cbn wheels for roughing. More so for chipper blades that are 5/8 thick. I Usually get these way off on the angle and the tormek is more of a finishing tool. Need something to rough it out for those times. It really is a fantastic machine. I really like using it. I like the fact there is technique involved and seeing the water in front of the blade with that certain sound is almost like therapy. I really enjoy working on this machine. Completely in the moment!

 

[cdhknives]

For the OP: I use my belt grinder for almost all sharpening jobs. Multi speed helps a lot, as slow is generally the name of the game here, but you can do good work with the (FAST) 1x30 and 1x42 belt sanders...with a light touch. You will hear those words a lot...light touch. Yes there is quite a trick to holding the blade at the correct and consistent angle, but it really is easier than doing the same on a stone. Practice is the key. Use scrap carbon steel if you have some. Cutting edge down for safety, BTW...closest I have come to serious injury in the shop was when I disregarded this rule. The edge WILL eventually snag the belt and cause the knife to get thrown if you grind it with the edge pointing towards the rotation/movement of the belt.

120 grit to rough in an edge, 320 to finish for most working blades. 600 and higher for bragging rights edges but it really isn't necessary for anything short of a shaving razor. Use a light touch. Cool the edge in water between passes. Look for a thin foil of metal on the trailing edge...the 'burr'. Once you have it the full length of the edge you are done for that grit. Strop or whet the burr off with a very light touch. I use a fine or extra fine diamond steel at roughly double the edge you were grinding. Yes you are 'sharpening the burr'. A couple of strokes and it is hair flinging sharp, a few more and the edge will be more durable but only shaving sharp.

Deciding on the edge angle is tricky. Best bet is to follow the original grind as best you can. There is some science in the angles chosen...think of the difference between an axe and a straight razor, for an extreme example.

Lots of youtube vids...most are decent. Some less so...use your BS detector.

 

[cdhknives]

BTW, the biggest difference in final grit is thus: The coarser grits leave a more 'micro-serrated' edge, better for slicing cuts. The finer you go the more the blade is optimized for 'push cutting' like a razor blade or chisel. Pocket knives, skinners, kitchen slicers, all seem to work better when finished no finer than 600 grit. Straight razors, large chopping kitchen knives, and so forth show definite benefit from the polished edge you get from stropping, water stones, leather wheels (power strops) and so forth.

Finer grits generate more heat for the same amount of metal removed. Better alloy steels generally temper at higher temperatures and are more resistant to getting softened by over grinding. Simple carbon steels temper quickly and at relatively low heat. You can hit 400+degrees (common tempering heat for low alloy carbon steels) in small regions (cutting edge!) very fast at fine grits. Light touch and dipping in water between passes helps a lot!