MDF strop with diamond compound

kwakster

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This type of strop is what i sometimes make & give to people who regularly bring me a CRK or other quality (Chef-) knife for sharpening and/or some TLC, so they can maintain & keep the appearance of their new edge themselves for some time.
Even a few professional Chefs in my area with expensive gyuto's and santoku's in modern PM steel types are using these same strops with good results, so they keep telling me anyway.
I use them myself as well, and they are easy to make.

It's a new & cut-to-size piece of clean MDF coated with a thin layer of 1.0 micron (+/- 14000 grit) mono-diamond compound, and i put 4 self-adhesive rubber bumpers on the bottom.
These bumpers make the strop non-slip plus they elevate the working surface a bit more which makes the strop more convenient to use on a table (more room for your hands)
Due to the harder surface the chances of rounding your crisp apex are also greatly diminished when compared to stropping on compressible materials like leather.
The strop surface can also be cleaned from time to time with a microfiber cloth and some acetone, which will remove all or most of the swarf without removing the diamond particles, as these become (partially) embedded in the MDF surface during the stropping proces.

But this is (literally) the key element: the placement on rubber bumpers also provides the strop user with acoustic feedback by isolating the MDF from the table (a bit like the bars on a xylophone); you can actually hear when you're arriving at the very apex during stropping movements as the audible sound changes, which makes the stropping proces very easy, even for absolute beginners.

The CRK Nyala used as a prop for the pictures was reprofiled (from 35-40 degrees inclusive to an even 30 degrees inclusive) & sharpened (with 15 micron diamond compound on a Paper Wheel).
The owner only uses this quite expensive knife to cut oranges, about 5 each day, i kid you not, :steirer:



 
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MDF is short for Medium Density Fiberboard, and you can buy it in stores like Hornbach, Gamma, Praxis, etc.

This would be a dependable US dealer for better quality diamond products: https://www.techdiamondtools.com/
I buy my diamond powders there, but the owner also sells good diamond pastes.
He ships all over the world in small padded envelopes.

They also have a Facebook page: https://www.facebook.com/lapidarypaste

Owner: Yuriy Ma
Address: 10511 Glencoe Drive
Cupertino, California
95014 USA

Direct link to his diamond pastes: https://www.techdiamondtools.com/sh...ncentration-diamond-powders-h-of-10-grams-11/

I do not know how much shipping will be to Germany, but for the Netherlands it was very reasonable.

This is the professional grade diamond compound i use on my Paper Wheels as well as for these strops, but it's much more expensive:

https://microstar2000.com/metallography/26/DIAPAT+Diamond+Paste
 
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Hi kwakster,

Thanks a lot for sharing again your knowledge with us!!!

As I am just at the beginning to learn about technical aspects of kitchen knifes, sharpening tools and cutting technics, cutting boards and so on, I appreciate very much indeed to learn from professionals like you!

Thanks again

Schärfefan
 
Hi Schärfefan, you're welcome and thanks for the kind words, :)

A professional however i'm not (i do not run a company), so "curious tinkerer" would be a better description.
Many years ago however i did do knife & scissors sharpening as part of my daytime job, but nowadays it's all just a hobby that sometimes gets a bit out of hand.
 
Hi Kwakster,
Your long experience makes your advices even more importent valuable..

There is nearly nothing reaching the importance of knowledge from experience in most professions ( and Hobbies:as well)...

I had just the idea: What about preparing the MDF stropping board after putting Diamond paste on it and before using it by rolling over it with a metal cooking pin or a metalic cylinder each time before using it? This would fix the diamonds immediatly onto the surface of the mdf corps and probably diminish loss of diamond- particles?

Shurely, too much pression has to be avoided since it would fix the diamond particles IN the wood instead of ON the surface of the wood?

On the other side, the stropping itself might be as effective as well... or even better, who knows...
Just my 2cents...

Cheers

Schärfefan
 
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I don't think special preparations are necessary; after i apply the diamond compound on the MDF surface a careful first stropping with the knife itself using the entire strop surface already makes sure that much of the diamond particles becomes embedded in the surface.
But don't let this keep you from trying your idea as well, maybe it turns out to be useful after all.

What is very important however is to use the absolute minimum of diamond compound to cover the strop surface, as too much compound will simply wipe away unused.
After applying the diamond compound on the MDF surface it should basically look as if untreated, then you're good to go.
 
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Question on another German knife forum where i also posted about this MDF strop:

"Do you think the Puma-polishing paste or Bark-River-compound will also work instead of the diamond paste ?
I don't want to add another item to my "sharpening collection" without properly using it.
The Puma-paste and the two compunds, however, are already at hand...
"

My answer:

"I have no idea as i've never tried those on MDF (or at all actually)
What i do know is that diamonds are much harder than whatever type of abrasive particles are in both the Puma polishing paste as well as the Bark River compound (both most likely aluminium oxide), so for the actual cutting & polishing of especially vanadium and niobium carbides (these are harder than aluminium oxide) in modern powder steel types like S30V, Elmax, M390, S90V, S110V, K390, etc CBN (Kubisches Bornitrid auf Deutsch) and diamond are your best options by far to get the best edge quality as well as the longest lasting edges on especially those steel types, as only these 2 abrasives can cut literally any type of carbide or nitride.
"
 
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