Since a few months i've been experimenting with a new way of knife sharpening (to me); natural rubber discs filled with loose grit, used on a simple benchgrinder.
The standard grit type used in the discs is aluminium oxide, but silicon carbide is also available and on my request that was used in my discs, or Rubber Wheels as i call them.
Each Wheel is custom made so you can also specify diameter, width, and axle thickness plus you have a choice from 2 different grades of rubber: medium hard type R.O.K. (colored red) or the softer type P.O.L. (colored grey)
The difference lies in the amount of "give" the surface of the Wheel has, which normally translates into narrower or wider edge bevels (although with some practice it is possible do both with each).
Because the larger part of my sharpening jobs are kitchen knives & tactical folders which normally have more narrow edges i first chose the type R.O.K. discs to test.
Also: since my old fast 3000 r.p.m. benchgrinder had been slowly dying from wear, this was a good opportunity to buy a new machine, and this time i opted for the slower 1400/1700 r.p.m. Creusen type DS7500TS, as this would be the perfect partner for the 20 cm Wheels which i wanted to use.
The smaller diameter discs however can handle higher speeds:
Diameter 20 cm: max. 2400 rpm
Diameter 17,5 cm: max. 2800/3000 rpm
Diameter 15,0 cm: max. 3200 rpm
After some chatting with Dick (the man who makes & sells the Rubber Wheels) i opted for 2 Wheels in 20 cm diameter (8 inch) with a width of 2,0 cm (0.8 inch) each, one filled with SiC grit 60 grains & one filled with SiC grit 180 grains.
At first both sounded way too coarse for my uses, but Dick told me not to worry.
The SiC grains are completely embedded in the rubber and come only gradually to the surface during sharpening, and because that surface also has some "give" the sharpening results would be much more smooth and even than expected.
Also the heat build-up is kept within safe limits, provided you do not use too much pressure while sharpening.
The Wheels give the best results if you let them do the work while you only use a light touch, but to be on the safe side i still keep a bucket of cold water nearby.
These are a few pics of the workplace where i do my sharpening.
In the back you can see my Tormek T7 wetgrinder fitted with an SB-250 Black Silicon stone (which i mainly use for serious reprofiling), and to the right is my new Creusen benchgrinder (set up backwards) with the Rubber Wheels (right is grit 60, left is grit 180):
Pictured separately:
Here are some pictures of edges created by the Rubber Wheels, first a Zero Tolerance 302 in CPM-S30V from a Dutch forum member.
(sadly my cheap camera doesn't show too much detail).
The factory edge was reprofiled and sharpened to between 30 & 35 degrees inclusive with just the grit 60 Wheel, after which the burr was removed with 3 micron diamond paste on the leather wheel of the Tormek:
A Zero Tolerance 0200 in 154CM steel from the same forum member, also reprofiled and sharpened to between 30 & 35 degrees inclusive with just the grit 60 Wheel, after which the burr was removed with 3 micron diamond paste on the leather wheel of the Tormek.
If you click 2 x on the second picture you can see the scratch pattern as well as a vague reflection of the camera housing.
A Spyderco Manix 2 in CTS-XHP steel, also from a forum member.
Reprofiled & thinned to about 30 degrees inclusive with just the grit 60 Wheel, after which the burr was removed with 3 micron diamond paste on the leather wheel of the Tormek.
If you click 2 x on the second picture you can see the scratch pattern, which in my opinion comes quite close to the original factory edge (be it a little convex)
This is one of my own knives (also a Spyderco Manix 2 with CTS-XHP steel), reprofiled & sharpened using only the 180 grit Rubber Wheel.
The resulting edge is about 25 degrees inclusive.
Summary:
When you want to sharpen knives on a regular basis you can now do that fast & economically on a simple benchgrinder you probably already own.
Since the Rubber Wheels are custom made they can be ordered to fit practically any existing benchgrinder and from what i've found will probably give you many years of service per Wheel since they wear only very, very slowly.
My former neighbour who is a woodworker has been using the same Rubber Wheel for about 30 years (!), and it still looks like it could do another 30.
The scratch pattern from both 60 and 180 grit Wheels maybe far away from a high polish (for that you would need Wheels with finer grits, which are available too), but the resulting edges are without exception very sharp (easily shaving in both directions and sometimes even hairwhittling), have quite a lot of bite, and according to various forum members & Chefs for whom i sharpen the edges also stay sharp for quite some time in use.
I paid a little under 70,00 Euro for each Wheel (about 92 US Dollars).
Dick's website in the Netherlands could use an update or two imo, but if you call or mail him he will see to it that you get what you need.
Send me a PM for more info.
Now i realize all this is probably less useful for US based forumites, but i think there is something comparable available in the US: google "Cratex Wheels".
The standard grit type used in the discs is aluminium oxide, but silicon carbide is also available and on my request that was used in my discs, or Rubber Wheels as i call them.
Each Wheel is custom made so you can also specify diameter, width, and axle thickness plus you have a choice from 2 different grades of rubber: medium hard type R.O.K. (colored red) or the softer type P.O.L. (colored grey)
The difference lies in the amount of "give" the surface of the Wheel has, which normally translates into narrower or wider edge bevels (although with some practice it is possible do both with each).
Because the larger part of my sharpening jobs are kitchen knives & tactical folders which normally have more narrow edges i first chose the type R.O.K. discs to test.
Also: since my old fast 3000 r.p.m. benchgrinder had been slowly dying from wear, this was a good opportunity to buy a new machine, and this time i opted for the slower 1400/1700 r.p.m. Creusen type DS7500TS, as this would be the perfect partner for the 20 cm Wheels which i wanted to use.
The smaller diameter discs however can handle higher speeds:
Diameter 20 cm: max. 2400 rpm
Diameter 17,5 cm: max. 2800/3000 rpm
Diameter 15,0 cm: max. 3200 rpm
After some chatting with Dick (the man who makes & sells the Rubber Wheels) i opted for 2 Wheels in 20 cm diameter (8 inch) with a width of 2,0 cm (0.8 inch) each, one filled with SiC grit 60 grains & one filled with SiC grit 180 grains.
At first both sounded way too coarse for my uses, but Dick told me not to worry.
The SiC grains are completely embedded in the rubber and come only gradually to the surface during sharpening, and because that surface also has some "give" the sharpening results would be much more smooth and even than expected.
Also the heat build-up is kept within safe limits, provided you do not use too much pressure while sharpening.
The Wheels give the best results if you let them do the work while you only use a light touch, but to be on the safe side i still keep a bucket of cold water nearby.
These are a few pics of the workplace where i do my sharpening.
In the back you can see my Tormek T7 wetgrinder fitted with an SB-250 Black Silicon stone (which i mainly use for serious reprofiling), and to the right is my new Creusen benchgrinder (set up backwards) with the Rubber Wheels (right is grit 60, left is grit 180):
Pictured separately:
Here are some pictures of edges created by the Rubber Wheels, first a Zero Tolerance 302 in CPM-S30V from a Dutch forum member.
(sadly my cheap camera doesn't show too much detail).
The factory edge was reprofiled and sharpened to between 30 & 35 degrees inclusive with just the grit 60 Wheel, after which the burr was removed with 3 micron diamond paste on the leather wheel of the Tormek:
A Zero Tolerance 0200 in 154CM steel from the same forum member, also reprofiled and sharpened to between 30 & 35 degrees inclusive with just the grit 60 Wheel, after which the burr was removed with 3 micron diamond paste on the leather wheel of the Tormek.
If you click 2 x on the second picture you can see the scratch pattern as well as a vague reflection of the camera housing.
A Spyderco Manix 2 in CTS-XHP steel, also from a forum member.
Reprofiled & thinned to about 30 degrees inclusive with just the grit 60 Wheel, after which the burr was removed with 3 micron diamond paste on the leather wheel of the Tormek.
If you click 2 x on the second picture you can see the scratch pattern, which in my opinion comes quite close to the original factory edge (be it a little convex)
This is one of my own knives (also a Spyderco Manix 2 with CTS-XHP steel), reprofiled & sharpened using only the 180 grit Rubber Wheel.
The resulting edge is about 25 degrees inclusive.
Summary:
When you want to sharpen knives on a regular basis you can now do that fast & economically on a simple benchgrinder you probably already own.
Since the Rubber Wheels are custom made they can be ordered to fit practically any existing benchgrinder and from what i've found will probably give you many years of service per Wheel since they wear only very, very slowly.
My former neighbour who is a woodworker has been using the same Rubber Wheel for about 30 years (!), and it still looks like it could do another 30.
The scratch pattern from both 60 and 180 grit Wheels maybe far away from a high polish (for that you would need Wheels with finer grits, which are available too), but the resulting edges are without exception very sharp (easily shaving in both directions and sometimes even hairwhittling), have quite a lot of bite, and according to various forum members & Chefs for whom i sharpen the edges also stay sharp for quite some time in use.
I paid a little under 70,00 Euro for each Wheel (about 92 US Dollars).
Dick's website in the Netherlands could use an update or two imo, but if you call or mail him he will see to it that you get what you need.
Send me a PM for more info.
Now i realize all this is probably less useful for US based forumites, but i think there is something comparable available in the US: google "Cratex Wheels".
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