MDF strop with diamond compound

[kwakster]

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.




What you see is a new & cut-to-size piece of clean MDF (medium density fiberboard) 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 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.

[HaioPaio]

Thanks for sharing. Could you be so kind to add a link to a source for the diamond compound?

[kwakster]

In general i use various professional grade diamond pastes from this US source:.

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

These are however rather difficult to obtain in the Netherlands where i live, and not exactly cheap either.
The pro's however are the sheer amount of diamonds in every syringe and their high quality grading.

A cheaper option and still good quality would be TechDiamondTools:

https://techdiamondtools.com/

Now i haven't used their diamond pastes yet (still have a rather large stock of the other ones), but some time ago i did buy a packet of coarser grit diamond powder from them, and so far this performs most excellent as a replacement for the standard SiC grit on a Paper Wheel.
Very useful for initial edges on especially high vanadium carbide rich steel types.

[Ken S]

Clever idea, Kwakster.

I would add only one minor suggestion. On the back where the information is noted, I would add a return address label with your contact information.

I have a strop which I cherish. It was a gift from my friend, the late knife maker, Mark Reich. Mark made and gave away several to sharpening friends. They are an inexpensive way to built a lot of good will.

Ken

[John_B]

I do something similar for my personal knives. I bought a new leather wheel and after seasoning it in accordance with Tormek guidelines I applied 1µ diamond spray. When not in use I store wheel in a ZipLoc bag.

I use guided honing and I have found that this results in a very sharp final edge.

[RichColvin]

When adding powdered diamonds to the MDF substrate, how do you ensure that they are not absorbed into your skin?  This is a problem with handling optical fibre, and it can be quite dangerous. 

[kwakster]

These days i use a disposable medical nitrile glove to rub the diamond paste into the MDF surface.
But in the past i've sometimes done it with a bare index finger, and washed my hands with soap & warm water before & after.

[John Hancock Sr]

Diamond is pretty much inert at room temperature so I would nit imagine that there would be any adverse effects. If it was absorbed then it would probably be absorbed into the body's fatty deposits or eliminated via the regular purging processes. If there is any good scientific research into this I would be interested to see it.

[RichColvin]

With optical fibre, the glass can be absorbed and end up in the bloodstream causing real havoc.  

A quick search using Perplexiy found this article of note as it regards inhalation of diamond dust https://pubmed.ncbi.nlm.nih.gov/16201206/

[Ken S]

I agree that we should have more and better research on the health effects of working with diamond dust. However, I also feel that this is not Tormek's responsibility. Neither the diamond compounds nor MDF wheels are Tormek products.
Tormek recommends using its diamond wheels with ACC solution and with PA-70, an aluminum oxide based honing paste.

Whether or not diamond dust poses a health risk, protective gloves seem a prudent measure. I have never liked the idea of using either CBN or diamond wheels dry. That seems to defeat dustless grinding, one of the core benefits of using a Tormek. Grinding in such a way as to require wearing a dust mask with a Tormek seems a needless constraint to me.

I see no problem in including these safety issues in the forum discussions as long as we realize that, as third party products, the third party vendors and not Tormek have the responsibility for their safety.

Ken