Beyond scary sharp

[Uncle Bill]

Adapting some techniques I learned at band instrument repair school about getting a mirror polish on a brass instrument, I've just discovered a way to make a blade so sharp I'm scared to carry it. I'm talking beyond frightening . . . absolutely mortifying.

Use a lansky or ceramic sticks or Arkansas free-hand, or whatever until you have your hair-popping standard razor edge, ready to make all those little bare patches on your arm.

Now take a 1/4 horse-power 1800 rpm motor, attach a Jacobs chuck, screw it down, put a six-inch hard cloth buffing wheel in the chuck, and load it with tripoli compound.

With things set up for the front edge of the wheel moving downward, polish the blade (edge downward, pointing in the direction of the spin).

Be sure to wear eye protection, gloves, etc. One slip and . . .

Next, go to a new wheel, a little softer, and move to a little less aggressive compound. At a certain point you'll be holding a blade that can remove a cougar's whiskers without disturbing his sleep.

(Don't attempt this if you have the slightest doubt about how to do it safely: direction of spin, location and angle of knife, etc. Mistakes doing this kind of thing yield results so quickly that it's all over before you've even seen what happened. I take absolutely NO responsibility for somebody's carelessness trying this.)



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I don't want my children fed or clothed by the state, but I would prefer THAT to their being educated by the state.

 

[Chefget]

I can attest to this method, since it was explained to me by RJ Martin (or at least this was what I took away from the discussion).

In discussions with a vendor of wheels and cloths, the "grab and throw" capacity of the cloth came up...haven't bought the wheel yet...

-Michael

 

[Dr.Lathe]

Yes this works just like you said!!! I use a slightly different method using my belt grinder with a very fine belt with a little compound on it. Then, either the buff or if its a thicker edge a leather strop with compound on it.
I have worked around buffers since I was a kid. I would be more likely to bounce one off the floor while polishing the rest of the blade than the final edge!!!!!
I will have to try the cougar thing on one of our Fl panthers.......

[This message has been edited by Dr.Lathe (edited 30 August 1999).]

 

[Dirk]

UncleBill, your not one of those guys that can sharpen an old file with rock you found in the woods, are you?

My dad had an old skinning knife that was so sharp, you could cut yourself and not feel it. I cut myself with it and didn't realize it until a good flow of blood was running. Even then I didn't really feel anything until I ran water over it. You should have seen my brother in law after he skinned a deer with it. He was used to using a relatively dull knife, he lost it and borrowed my dads. After he was done he couldn;t figure out why he couldn't get all of the blood cleaned off of his hands. It was his blood. He had cut hinself almost a dozen times and didn't even know it. OK, he isn't the brightest star in the sky.

He worked the original knife down to where there was no bevel at all it was flat ground from spine to edge. He used an extremely fine stone he picked up somewhere. Then he would take it through a series of strops, I think they were loaded with different compounds, I don't remember, I was young and he has passed away. It sounds like the same technique as yours except no power equipment.

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Paranoia is only smart thinking
when everyone is out to get you.

 

[Kisu]

That's how I've been sharpening my knifes ever since I started making them

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KSwinamer

 

[Uncle Bill]

Not being a knife-maker, or even having the slightest idea of what they do, I feel a sense of satisfaction discovering independently what you guys probably think of as "old hat." Anyway, watch your fingers . . . and stop shaving your nose hairs every time cousin Louie comes by. He's already impressed!

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I don't want my children fed or clothed by the state, but I would prefer THAT to their being educated by the state.

 

[Kisu]

You should feel satisfaction on that, I had to be told that, and you figured it out on your own, guess you have an "edge" on me

Ever think about making your own? Sounds like you might have a talent for it.

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KSwinamer

 

[David Williams]

Uncle Bill,

I didn't figure this out on my own but read David Boye's book on knifemaking and he had a chapter on sharpening using this method. I use belt sander first to develop a burr, then use the buffer to polish the burr out.

Hopefully pretty soon I can use this method again as I haven't even aproached this level of sharpness with stones. I inherited some power tools but they all need new motors.

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"A knifeless man is a lifeless man"
-Nordic proverb

 

[goshawk]

The only problem with this is it creates such a fine edgfe that is will dull faster. If
you want it even sharper that scary sharp
do a final buff with pink no scratch. YEEEEEEEEEOW!!!!!!! You can shave all the
hair off a griz from 1/4 mile without even
lookin at him.

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http://www.imt.net/~goshawk
Don't walk in tradition just because it feels good!!!!!
Romans 10:9,10
Hebrews 4:12-16
Psalm 91

 

[Jeff Clark]

I worry that using power equipment will put heat into the microscopic edge faster than it can spread out through the blade. This lets you get a very sharp edge that is slightly soft right at the edge. Thats one of the reasons I like to finish my hand honing going light and slow. It is also the reason I favor wet honing for heavier work.

Of course I have no real test data, just a hunch from my understanding of the heat generated by abrading metal and the geometries involved. If you remove material or generate friction you will be putting heat into your work piece. It's always the thinnest edge that burns.

As a side note, I generally don't want an edge that smooth unless I'm using it to shave with. I would go back and take a few light swipes with a fine stone or ceramic rod to give the edge a little tooth when I was done. It would still shave, but would also cut better in most practicle cases.

 

[Uncle Bill]

As for heating up the fine edge, wouldn't that depend a lot upon: (1)the speed of the motor, (2)the type of wheel, and (3)the coarseness of the compound? I mean, 3600 rpm with tripoli on a 12" hard wheel seems like a completely different animal than 1800 rpm with red rouge on a soft wheel.

I have no idea what the edge temperatures are at the microscopic level even when doing it all by hand. Ripping metal off with abrasive materials must look pretty ugly at 1000x power, regardless of the speed at which it's being done. Someone enlighten me.

Also, if the original ground angle makes a thicker wedge (pardon my lack of vocabulary here) wouldn't that make a difference? My "beyond scary" edges aren't thin at all. Just smooth as all get out.

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I don't want my children fed or clothed by the state, but I would prefer THAT to their being educated by the state.

 

[Cougar Allen]

I've done it both by hand and with a powered buff, finishing with Raybrite A which is a sub-micron aluminum oxide used to polish gemstones. I consider it a waste of time except for specialized uses so I stop at tripoli on leather. It's fun to do once or twice just to see that you can, though.

If it's all the same to you, I'd prefer you don't sneak up on me and shave my whiskers when I'm sleeping ... I'm quite attached to my whiskers....

-Cougar Allen :{)

 

[Bagheera]

Hi, I just got the retailers catalog from Buck knives 1999 and there they use the "new" edge2000 as they call it that makes their knives perform better then they used to.
They explain that the final stropping/buffing is not done anymore on a soft" cloth/felt wheel with some polishing agent but on a hard leather wheel that looks to me like being a 8-10" diameter wheel with leather outside.
This according to Buck does not round the edge like the softer wheels could do in the final stropping/polishing fase of sharpening.
Looks like they invented the wheel all over again.
Cheers, Bagheera


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[allanm]

This is just a thought but wouldn't it be better to work from the back of the wheel with the edge and rotation going away from you. That way if the knife gets thrown it will be away from rather than at you.

 

[Ken Cook]

Somewhere back in the old threads, there's a couple on "Rolled Edges" and "Convex Edges."
This is pretty much what you guys are talking about.

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I cut it, and I cut it, and it's STILL too short!

 

[longbow]

I may be able to use some help with a problem I am having with my Black Jack Trail Guide. I stupidly put a cantle on the convex edge with my Diamond Lansky hones. Although at first it was extremely sharp and grabby after some use it is now indeed super dull to the point it is dangerous. Not only that but the edge won't come back the way it was at first no matter how much I try. I am led to believe it is the thickness of the convex edge that is keeping it from doing so.
Anyways would anyone care to volunteer to put an edge back on it for me, of course recompence would be accomodated too.(I will give some renumeration is what that means) Any help is gratefully appreciated. thanks and keep'em sharp.

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[Dr.Lathe]

Longbow,
I have brought back some realy sad looking knives to "scarry sharp" I use the power tool methods as discussed above. Depending on the material I buff or strop! Sounds like some minor grinding before the sharpening begins!!!! The knives I make have a factory looking edge that pops hair. I can do a micro-seration type edge or a very smooth one. I have customers request both.
I have often thought of offering this service to the Forum members. I don't want to try to get rich off doing this, but it would have to pay for my time!! I work a full time job while turning out about 2-3 knives per week. Usually this sharpening method only takes a matter of minutes. I know that there's lots of knives out there that are realy hard to sharpen with hand stones!! What would be a fair price to charge in addition to shipping?? The price for a service like this would be more to cover time spent packing and driving to the post office rather than the sharpening!!
Any thoughts on this would be appreciated.
Email me if you would like more info.