Do you get a better edge using dry stones?

D

Don M

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Apr 30, 2000
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I picked up a copy of Juranitch's book, The Razor Edge Book of Sharpening, at SMKW the other day, and something he said caught my eye. He says that you get a better edge when you use a dry stone, rather than using oil.

I have always used oil on my Arkansas stones (water on DMT), with good results, but I can't argue with his experience, including the use of electron microscopes to inspect the edge, which he says revealed small chips in the edges sharpened with oil, and not on those sharpened dry.

Two questions:

1. Those who have sharpened both wet and dry, do you notice a difference?

2. How do I keep my Arkansas stones from clogging, or how do I clean them, if I use them dry?


BTW, it looks like SMKW is expanding, with what appears to be a large addition under construction. Hopefully that will translate into an even larger selection of knives.
 
First of all Juranitch's conclusions are wrong. He leads you to believe that an edge that looks clean under an electron microscope is a better edge, which has not been established at all. Actually microscopic surface roughness can help a blade slice. Unless you hold a blade in a mechanical fixture you always get at least a little transverse slicing motion. That little bit of edge tooth helps in most cases. It may also work for some kinds of push cutting through hard, but sort of brittle materials to start the cut via a cracking action where you have sort of a microscopic tooth to start the fracture.

The smoothness that he sees is probably due to wearing the points off of the hones surface grit and filling the hone with honing debris. That dry hone will typically cut a lot slower than your oiled hone. A water hone works by taking advantage of water to speed the breakdown of the surface grit to expose fresh sharp grains and also to release and flush out the pores of the hone. Your oiled hone works similarly, on a lesser scale. The way that I would match Juarnitch's results (if I wanted to) with a wet hone is to start with the same grit that he used, but on a water hone and finish with a finer grit water hone than he was using. This would cut a lot faster than just doing the whole thing dry.

If you insist on trying to clean out your oil stone you will need to boil it in a dishwasher detergent solution. I wouldn't bother. I would go out and buy a finer grit hone to finish with if you think that you really need a smoother edge. I like ceramic hones for that purpose.

You are probably reducing the life of your diamond hone if you are using it wet. You want to flush out debris (which includes diamond residue) frequently as you go. If you leave water on the surface of the hone it will build up. When I use a diamond hone dry I keep a terry cloth rag handy and dust the hone surface frequently. I also work wet, but I do it under running water to constantly flush the hone surface. I do this under the tap in the kitchen sink.

So in conclusion, "going dry" will slow down your honing and leave you with an edge that will slice less effectively. Get an extra fine hone if you want to get a finer finish. Going dry will be less messy. For the best of both worlds go to using Japanese water stones.
 
I also disagree with Juranitch's recommendations. I purchased his book and noted he is mainly selling to the commercial meat processing industry. They use much softer steel on their bucher knives and want a quick edge sharpening with simple tools. The dry stone is better than the usual serrated steel that is also popular.

The use of water or oil is very important in the design of sharpening hones. I have recently been using cheap mineral oil (baby oil) from grocery stores. It does not cause rust on the diamond hones and will work fine on arkansas stones.

The softer Japanese waterstones and synthetic Shapton stones are designed for water as a lubricant and wash, no oil on these stones as they will clog up.

Regards,
FK
 
I agree with what Jeff has already stated except the part about reducing the life of a diamond hone by wetting it. IIRC DMT states that by applying water to the diamond hone that it will actually prolong it's life. I have a small cup of water that I use to sprinkle on my DMT hone while sharpening and continue to keep it flushed and clean after every couple of minutes of sharpening. To clean all of my stones(diamond and natural)I use a little comet or soft scrub along with a nylon bristle brush under the kitchen faucet. Still work like new after several years of doing it this way. :)
 
His work was repeated by two others, including Leonard Lee. the others found that wet honing did *not* produce the chipped edges that JJ claimed.

-Cliff
 
I get good results with a dry stone, and it is easy to scrub a stone under water after with a brush to clean it.

That said, I have similar problems as others with JJ's conclusions. I had a Razor Edge kit (very nice kit, by the way) and whenever sharpening, stone dust would ride on the edge in the same way that JJ wrote about stone and metal dust suspended in oil woudl ride over the edge. If there was any truth to the "chipping due to debris abrasion" theory, I would think that dry debris running over the "top edge" would be much more hazardous to an edge than debris in an oil/water mix.

Nowadays I use my belt sander, King brand waterstones, an Edge Pro, and a diamond stick for sharpening. I'd like a super fine ceramic rod, and a DMT double sided diafold, and an x-coarde DMT stone, and then I'd be happy!

Well, it would be nice to have a room full of CATRA equipment, just for fun :)
 
Part of the reason that I gave up on Arkansas stones is that I got tired of the mess of using oil. I just don't see how you can use them without oil. Sometimes I would resort to using alcohol which worked OK, but was inclined to dull the finish on lot of knives. I use a belt sander for rough work these days (dry) then I go to either diamond hones under running water or a water hone, and finish with the Sharpmaker ceramics. I only use oil when I am trying experiments.
 
In my experience and personal opinion on all of that...

dry works faster and gives a better edge but will wear out hones faster and cause them to clog. I, personally, would rather replace stones than work my butt off sharpening - this includes diamonds.

You have to decide when you get a new stone because once you've oiled it you have to keep it oiled.

You can clean a stone by using one of those kneadable soft grey erasers on it.

That said, the water method instructed with the EdgePro works very well if you keep the stone and water clean and keep it wet and wiped down.

I don't like oil at all. I believe it creates a slurry of an oil/grit mix that works against you while you work.

My problem with Juranitch's was that he expects everyone to regrind the main grind of a knife destroying it's look and possible coating. I took what I liked from the book and left other stuff that I didn't agree with.
 
I believe you have to take JJ's conclusions in the context of not only his book, the market he is aiming at and his products. I have used the Razor Edge stones for some time now and I believe they are some of the best available of that type of stone and they do work best dry but I do not believe this applies to other stones such as Arkansas which are better used with oil. Also top quality oil stones are already presoaked and need to be used with oil.

I believe that most of JJ's conclusion are based on the meat industry which is a totally different environment to that of the hunter eg. Not only do they require softer blades but they also require and edge that will not increase fatique during the day. I do not know what the health regulations are in the US but here in Oz meatworkers must use dry stones - they cannot use oil or water stones. The only exception is in the pet food industry.
 
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