Sharpening

[hso]

I always caution knife owners to stay away from their power tools in their garage without a lot of practice and a lot of different grit abrasive belts (and the willingness to ruin knives learning how to use them).

The only exception is the Work Sharp system, but they make it nearly idiot proof if you can follow instructions.

 

[Smokey Joe]

Learning curve on a belt sander...

Hso--and Zeke--How I learned to use the belt sander was by using several nondescript kitchen knives from St. Vinnie's, and rummage sales; went ahead and sharpened them, well or poorly as the lesson went. At between $0.25 and a buck apiece, and I didn't care about the knives in question, it was cheap learning. (And, I had some nicened-up kitchen knives to give away, too!)

Next I did all our own kitchen knives, with no mishaps, even though the steels varied quite a bit: Everything from antique hi-carbon to rather new stainless. The Chicago Cutlery knives sharpened up particularly well; Old Hickorys right behind them. Hardest to do are filet knives--they're so whippy.

Then I began sharpening hunting knives for friends, and rehabbing misused knives. Have gotten pretty good at that in my own humble opinion. By now there is considerably more $$ in my 1x30 belts of various grits, than in the machine that turns them.

As I said, I'd learned years ago to maintain an angle, using carborundum, diamond, and natural stones. My Dad started me on that as a youngster. I have my Grandfather's Medium Arkansas.

So far, I don't believe I've destroyed any blades. The people for whom I sharpen seem very happy with the results.

Am currently in the final stages of grinding out my first knife from de-tempered car-spring-steel. (Grinding wheel partly; belt sander partly, and COOL IT OFTEN!!) An acquaintance has a furnace with electronic controls, for tempering, oil plunge, and re-heat a little, and allow to air-cool. Then, as the man said, we shall see...

BTW, belt sanders are what the pros use. Have you been watching the show, "Forged in Fire" competitive knife making--Those guys REALLY know what they're about, and besides hammer-and-anvil forging, belt sanders are about all they use for making their blades. I couldn't begin to afford the pro-level 2x72 belt machines they use.

 

[Valkman]

I couldn't begin to afford the pro-level 2x72 belt machines they use.

They run $2-4K for a good one but the problem is you can't hold one angle by freehand sharpening it on a grinder. I've taken knives I've made and put them on my Wicked Edge system (I got it after I quit making knives) and they take a while to straighten out. Next time I'll put an edge on with the grinder and finish with the WE.

 

[george burns]

I have a worksharp, a spyderco, several stones and a :twice as sharp. They all serve different purposes, the Sharpmaker is a nice compact unit that always gives you a nice edge in a pinch. They all take a little time to get the hang of, and when you do High end hair shears, $500.00 and up, you better not screw them up unless you carry insurance, they are convex edges with a 8oo mm ride line, but the simple stuff like pocket or hunting knives are easy, just time consuming.

 

[Smokey Joe]

Woo!

Valkman--Those are some really nice looking knives! Their general style is about that to which I aspire.

 

[Valkman]

Thank you, I hope to get back to making them this fall/winter.

 

[Zeke/PA]

When I was making knives, I built a grinder that takes a 132 in belt so I could hollow grind my blades.
The contact wheel is 8 in. in diameter and of course different grits of abrasive were used.
Final sharpening though was done on bench stones, the final touch being hard Arkansas.

 

[GLOOB]

I find it odd that preset sharpening gadgets are so popular with knife enthusiasts.

When I was a kid, I bought a lansky, and I couldn't even figure out how to use that. I was pretty clueless. As an adult, I can put a razor edge on just about anything, using nothing but stones or even sandpaper. And I would hardly ever intentionally put the same bevel or edge on a knife, all the way across.

As far as sparks ruining the temper, some people don't understand how that works. A steel spark has temperatures exceeding 1000F, but that doesn't mean the underlying steel exceeds 300F. Steel is a pretty good conductor of heat. The edge is protected from excessive temperatures by the surrounding material which continually wicks away the heat. As long as you cool the blade, periodically, you will be fine. I made a custom, job-specific chisel out of a piece of hex bar, the other day, using nothing but a belt sander followed by 30 seconds on the ark stone. It is shaving sharp, according to my arm, and it holds an edge as good as any chisel I have purchased.

 

[cdk8]

I love the SharpMaker! It is arguably the best sharpening system anywhere near its price. I use a SharpMaker for touchup these days...I used it for a decade as my primary sharpener. Now I use an Edge Pro with Chosera stones. I usually go up to 5000 grit and for my main carry knife the edge is on around a 10 degree angle.

 

[Evil-Twin]

Evolution of sharpening

In my 70 years of life, and being a sportsman since I was 15, I.ve carried many knives. The idea of a sharp knife comes with ownership of a knife. Like everyone else, we all try to make our knives sharp. We do research, go to you tube, read reviews and claims by manufacturers. The type of hardware we buy to accomplish this feat is only part of the sharpening equation. The things that fails in most cases is the technique used by the sharpener, and the ability to use the exact same angle with each stroke.

There are plenty of sharpening devices out there.. you can buy all types of stone, and inexpensive devices all under 100 dollars. Then you move into the next type of hardware in the 100 to 300 dollar range, and the address the angle repeatability. then there is the Wicked edge which not only makes an edge so sharp its scary. It also locks the blade in a vertical position that can't move. the angle you use is also locked into a very specific angle of your choice, it does both angles at the same time, and can do 3 angle bevels.

IN my twilight years, I took a chance and spent the 800 dollars and bought the Wicked edge Pro Pack . I wanted to see if this system was all it was cracked up to be.. If it wasn't IU would send it back, it has a lifetime guarantee. I've read hundreds of reviews.

I've tried many types of sharpeners over the years, and never really was blown away by the results. The best Ive ever had was a factory ground knife and when it got dull, I could never quite achieve a factory edge.

Enter the wicked edge, after a very small learning curve, I've been able to take a factory sharp knife, and make it wicked sharp.. I've spent several hundred dollars over the years seeking that insane edge, but never found it until now., I have nothing to do with wicked edge, wish I had bought this system 50 years ago. For the first time in my life, I have razor sharp knives, nothing comes close to the insane sharpness achieved.
This system sharpens a knife so sharp that the typical slight touch with three fingers yield bloody fingers. I never had the respect for a sharp knife because I never really knew what a sharp knife can be. This system makes a box cutter razor blade by comparison a butter knife. A wicked edge has taught me the respect for a sharp knife. when you are talking about the best, go and view a few You tube videos on the Wicked edge.. Ill tell you this, I wont be sending my Wicked edge system back. Its expensive, for sure.. but its worth every penny. This system removes all the operator error, found in other systems.

After I sharpened my first knife ( Photo )



Note the sharpness of the edge... you would not want to touch this edge. Note the reflection of the edge. This edge can be achieved with any knife every time, and without any concern for molecule migration ( Belt sanders ), changing the harness of a quality knife. Angle 13.5* degrees...The final step with this system is the use of 50,000# grit diamond stropping paste on two Kangaroo leather strops..









It doesn't cost anything to check it out, Lifetime guarantee..
I have nothing to do with this company. wish I knew about this years ago.

Bill aka ET

 

[redneck]

Hardness has nothing to do with how fast molecules are moving or how close together they are.
Steel is an alloy containing many compounds. These compounds mix together and form different structures at different temperatures. You can have cementite, ferrite, pearlite, martensite, and austenite and it all depends on the temperature, and the alloys present. Some stainless steels will be austenite at room temperature, while others used for knife blades have to be heated to 1800+ degrees.

When you heat treat a knife, you raise the temperature until the carbon dissolves causing the formation of austenite. The blade will be non magnetic at this temperature. You hold it at this temperature for a period of time to insure that the carbon has completely dissolved.

The next step is to cool down/quench the blade. If you do this slowly the carbon will separate itself and pearlite will form and you will have a soft unuseable blade. If you do this quickly, you form martensite and the carbon is trapped making the steel very hard. In either case if the molecules were moving, they would move the same speed at a given temperature, the difference is the arrangement of the molecules and that is determined only by the speed of the quench.

Finally you temper the blade. This is controlled heating to draw some of the carbon back out of the solution. For most simple tool steels this requires heating to 400 degrees or more for over an hour. The steel takes on a straw colored oxidation on its surface. Some high alloy steels require even hotter temperatures. D2 for example will still be at RC 57-58 at 700 degrees F while 5160 would be pretty much useless. At 700 deg the steel will begin to turn blue.

If you are sharpening on a power tool, and you don't see any discoloration and you can hold the metal with your bare hand, you have done no harm to the blade. If you turned the blade yellow and held it there for an hour you would only be re-doing what was already done once before. You would have to see discoloration that is blue or purple to have harmed the knife, and in some cases, depending on the alloy, even then it is far from being ruined.

 

[Evil-Twin]

I hope you are not talking to me??? harness is a product of heat treating and then quenching, this locks the molecules close together under specified conditions of the type of harness and the metals used. when you heat up a blade ( with a belt sander ) it unlocks the chain and allows the molecules to migrate away from each other causing the structure to change. This reduces the temper because it has changed the desired structure.
AS a Retired engineer, I've done this for a living for 30 years. I've Rockwell and Tinious Olsen non destructive tested the results of heating metals and the changes to their molecular structure..

I wont comment further. take it or leave it... I wont put a belt sander to a 400 or 500 dollar knife, let alone a 100 dollar knife.

 

[Valkman]

I bought a WE system a few years ago and it's the best thing I ever did. Easy to use and learn, after you break-in the stones you can get results like those above. I use leather and balsa strops to get that reflective edge.

 

[Evil-Twin]

AS I've said, this system is expensive. But the results speak for themself... there is no guesswork in the angle, and it is repeatable from stroke to stroke,

I've never known what a truly sharp edge was until I used this wicked edge system.

you can take a human hair and whittle it three times ( one single strand )... with three plums using a wicked edge sharpened blade... Check out wicked edge on You Tube if you want to see it..


https://youtu.be/uMenpmayado

 

[hq]

My choice has been Tormek T-7 lathe with waterstone and leather wheels and a full jig set. It's heavy, bench mounted and a bit spendy, but IME one of the quickest and easiest tools to shape and sharpen any blade to very precise angles. Once you get used to setting it up and using it, you won't bother sharpening one or five knives at a time anymore, you'll do your entire collection in a couple of hours "while you're at it".

I think I've spoiled my wife, she keeps bringing me kitchen knives that are still far sharper than they ever were when they were new, because she thinks they're already dull.

I'll probably have to give Wicked Edge a try. It seems quite a bit more portable than Tormek will ever be.

 

[Valkman]

I used a Tormek once, they are very good sharpeners.

 

[GarySTL]

I have an older Tormek that I bought for my woodworking tools. Works well for knives too.

 

[redneck]

I hope you are not talking to me??? harness is a product of heat treating and then quenching, this locks the molecules close together under specified conditions of the type of harness and the metals used. when you heat up a blade ( with a belt sander ) it unlocks the chain and allows the molecules to migrate away from each other causing the structure to change. This reduces the temper because it has changed the desired structure.
AS a Retired engineer, I've done this for a living for 30 years. I've Rockwell and Tinious Olsen non destructive tested the results of heating metals and the changes to their molecular structure..

I wont comment further. take it or leave it... I wont put a belt sander to a 400 or 500 dollar knife, let alone a 100 dollar knife.

Sharpen however you want, but hardness is a function of the arrangement of the molecules and is not because of how fast they are moving and is not because they are closer together making the material is more densely packed. Martensite crystal structure actually has the molecules farther apart if you want to keep going there.
Everyone should sharpen how they are comfortable but there is too much smoke and mirrors and misinformation in regards to heat treatment getting thrown around on forums like this.