Diamond Stone longevity

B

Barmaley

Joined
Dec 31, 2016
Messages
220
Howdy,

How long should I expect a diamond stone to last? I bought a SHARPAL 162N Double-sided Diamond Sharpening Stone Whetstone knife sharpener with Storage Base | 2 Side Grit Coarse 325 / Extra Fine 1200 from Amazon and I was amazed with its performance: it cuts extremely fast! However, after about 20 knives its course side became completely dull and the fine side almost gone. I called customer support at Sharpal and they sent me a new stone which I got today free of charge. The new stone looks excellent but I am concern about how not to ruin it again? I was not using water of oil with but I was applying very light pressure. Do I need to improve my sharpening technique or I need to switch to a better brand or I should not expect Dimond stones to last?

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Barmaley said:
Howdy,

How long should I expect a diamond stone to last? I bought a SHARPAL 162N Double-sided Diamond Sharpening Stone Whetstone knife sharpener with Storage Base | 2 Side Grit Coarse 325 / Extra Fine 1200 from Amazon and I was amazed with its performance: it cuts extremely fast! However, after about 20 knives its course side became completely dull and the fine side almost gone. I called customer support at Sharpal and they sent me a new stone which I got today free of charge. The new stone looks excellent but I am concern about how not to ruin it again? I was not using water of oil with but I was applying very light pressure. Do I need to improve my sharpening technique or I need to switch to a better brand or I should not expect Dimond stones to last?

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The electroplated stones are a single layer of abrasive plated on a surface you have to use light touch to prolong that single layer of abrasive grain. You don't want them to prematurely dull or tear off the plate, regardless of how careful you are eventually that single layer will wear out and go dull.

We have to remember that when something is harder it doesn't mean it's also not affected when interacting with softer materials, it just experiences less wear.


There are more expensive diamond stones on the market that are a full thickness diamond in a bonding matrix not just coated on a surface, the advantage to these types of diamond stones is that they will create a better surface finish, they will also last longer and can be used with more heavy handed force without concerns of tearing out the diamond depending on the bond of course.

So not all diamond stones are the same.
 
Barmaley said:
Howdy,

How long should I expect a diamond stone to last? I bought a SHARPAL 162N Double-sided Diamond Sharpening Stone Whetstone knife sharpener with Storage Base | 2 Side Grit Coarse 325 / Extra Fine 1200 from Amazon and I was amazed with its performance: it cuts extremely fast! However, after about 20 knives its course side became completely dull and the fine side almost gone. I called customer support at Sharpal and they sent me a new stone which I got today free of charge. The new stone looks excellent but I am concern about how not to ruin it again? I was not using water of oil with but I was applying very light pressure. Do I need to improve my sharpening technique or I need to switch to a better brand or I should not expect Dimond stones to last?

​

Click to expand...
In my experience you need to use water, I think it floats the diamond that comes off the surface, which somewhat keeps the loose diamond particles from taking surface off. But, I have worn out a number of diamond stones. Heavy pressure is bad for a diamond stone, as it removes the diamond coating. Twenty knives is a very short lifetime, but I have not kept count of the number of sharpenings it takes to dull the surface. My coarse and extra coarse stones do smooth out, but still retain enough surface to sharpen, until such time as the surface comes off.

I have basically given up on fine diamond stones. I use a coarse, or an extra coarse to set the angle and even the bevels. Then I use a medium India stone to basically knock off the burr.

The red surface is the India part of this stone

rIAy8Zw.jpg



The Coarse India stone is black. Don't know why

5TWF1z3.jpg




I free hand everything. That magnifying glass is perhaps the most important tool I use to create a fine edge

qol8jFR.jpg


With the magnification that lens provides, I can see what angle I am holding the knife and what I am doing to the edge. And also, very important, I can see whether the bevels are centered.

To determine if a diamond stone is worn, I run a finger on the surface, when I find bare steel, I know it is time to buy a new stone.

Even India, carborundum, and Arkansas stones wear. In my apartment days, I would take a dished carborundum stone out to the sidewalk and use the rough concrete to true the stone. The concrete smoothed out too.

New carborundum stone

hdBMzPP.jpg


When visiting real old timers, I used to see on their benches heavily dished Arkansas stones in rectangular wooden containers. The owners were still using them, but it is just about impossible to get a fine edge when the stone surface is a curve. Water stone owners need to buy a truing stone as water stones dish very quickly.
 
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I’ve had a fine dia sharp diamond plate and have sharpened countless knives on it. It had to be broken in first because it was a little rough at first but after that its been great. No signs of wearing out yet and it cuts great. I clean it with soap and water once in a while.

I did have a problem with the lansky extra course diamond hone from the guided system wearing out very quickly. Happened on two different hones so I stopped buying them. I guess you get what you pay for.
 
Pressure and rough handling are not your friend with diamond plates.
I don't know about this brand specifically, but people use diamond plates for over a decade when handled right.
 
Thank you all for insight!

What is india stone? Which model should I buy? I use Norton Crystolon JB-8 and I love it! Is this which H helobite refer to: https://www.amazon.com/Norton-61463...351209&s=hi&sprefix=norton+i,tools,104&sr=1-3 Looks like it has similar grit to Crystolon JB-8? Is something special about India stone?

For my sharpening routine I use Crystolon to get 11.6 degree first bevel on the simplest DYI machine made of few wooden planks and then I use Sharpal ceramic rod which suppose to be 3000 grit. Then I strop on a printer paper and finish it on a leather strop. The goal is to keep the final angle at 12 degrees which as Vadim discovered the best to hold knives sharpness. Every big meal preparation I do a couple of strokes in the ceramic rod and strop on a paper. Am I missing something?

Since my diamond stone does not last I will reserve it for my only M390 chef knife and I hope the stone will last for a couple of year before I would need to buy a quality diamond stone.
 
Some folks claim to get years of use out of their diamond plates, but not me. I just can't maintain light pressure so I end up wearing them out pretty quickly. Bonded diamond/CBN is where it's at.
 
I use water with a drop of dish soap. It is easy to use more pressure than what you need. I'm sure some might use a better bonding material than others too. I've only used the KME gold plates.
 
Light pressure and lubrication (just soapy water is fine) helps prolong the life of diamond plated stones significantly.

The SHARPAL 162N diamond stone you have, is a diamond plated stone. Sellers and manufacturers often state that diamond or CBN plated stones can be used dry - and they can, but this will shorten their life significantly.

Even the cheap Chinese diamond plated stones with plastic backing that I have seem to last forever when used with light pressure and lubrication. At least a few hundred knives of new bevel setting, if not much more.
 
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I've been using my sharpal stone for a couple years now. The coarse side broke in and has stayed good that whole time, and has sharpened countless knives. Super steels to simple carbon steels and everything in between. Don't use the 1200 side much though.

Pressure is the key. I use mine dry, just don't bare down on them like they owe you money and they will last. For the price I paid (~$35) and the warranty (I believe 5 year?) I'm perfectly happy with them and their performance.
 
I used the same 6" DMT benchstones (fine, extra fine) for over two decades, and they are still in service by my BIL a decade later. Cleaning them with BreakFree CLP lifts the swarf off and restores their cutting efficiency. Currently I mostly use a 10" DMT (fine/extra fine) along with an extra coarse DMT DiaSharp220 grit for reprofiling.
 
Barmaley said:
So I guess Chrystalon is better since it is SiC. I mean it lasts longer and cuts faster?
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I don't think it would make so much of a difference with most steels. India stones are plenty aggressive.
SiC should handle super steels though, which aluminum oxide will not.
 
soc_monki said:
I've been using my sharpal stone for a couple years now. The coarse side broke in and has stayed good that whole time, and has sharpened countless knives. Super steels to simple carbon steels and everything in between. Don't use the 1200 side much though.

Pressure is the key. I use mine dry, just don't bare down on them like they owe you money and they will last. For the price I paid (~$35) and the warranty (I believe 5 year?) I'm perfectly happy with them and their performance.
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Priceless
 
Barmaley said:
So I guess Chrystalon is better since it is SiC. I mean it lasts longer and cuts faster?
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It cuts a bit faster but it won't last longer. SiC breaks down much faster than AlOx during use. They still last quite a very long time though.
 
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