stropping questions

[Ken S]

Here is a link to a well done stropping video done by our own Sharpco.

https://youtu.be/iORw_kvsuDw

Sharpco has demonstrated both very solid, well executed Tormek technique and innovative ideas. This particular video uses a flat strop with Tormek PA-70 honing compound. I regard techniques differing from traditional Tormek technique when done by an accomplished Tormek user as opportunities to expand our horizons. This video makes me think.

The original Tormeks did not have honing wheels, leather or otherwise. Was the round leather honing wheel chosen instead of a flat honing surface because of superior results? Or, might it have been chosen because placing it over the drive wheel made a convenient design feature? I am just asking the question; I have no hidden agenda. Just as paper or felt wheels in a higher speed buffer hone more quickly than the Tormek leather wheel, The motorized Tormek leather wheel is faster than a flat board. What is the ideal honing speed? (I can see where the answer might depend on the volume and quality demands of the particular job.)

I salute Sharpco both for his polished skill and his willingness to venture beyond tradition.

Ken

[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.

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 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 dimished 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.

[van]

Good idea. To try.

[John_B]

This looks like another very interesting avenue to go down.

Rob
Can you please post a source of the 1µ diamonds you use? Also what MDF board did you use? I am hoping that I can find a suitable plank that I only need to cut to length.

[Elden]

What is MDF (medium-density fiber) board? I have heard the term used for sometime and decided to look it up.

https://www.realtor.com/advice/home-improvement/what-is-mdf-furniture/

[Ken S]

Elden,
I started using MDF only recently. I needed to make a top and a shelf for my wood lathe stand. MDF is made from glued up wood chips. Due to the amount of glue in it, it is heavy. However, it is also quite smooth and flat. With a fine tooth blade, my circular saw cut it very nicely. It is also much less costly than Baltic Birch plywood. It is available at the big box stores in different thicknesses (from 1/4" to 3/4") and different dimensions. 2x2 or 2x4' would make many strops and easily fit in small cars.

Kwakster, what dimensions have you found to work well?

Ken

[Gary@QSS]

Another point to keep in mind - don't let MDF get anywhere near water. Moisture is it's killer.

[Ken S]

Thanks for that information, Gary. I have not used MDF very much and was unaware of that problem. If I ever turn green wood bowls I may have rethink or redo my lathe stand top.

Ken

[RichColvin]

I use MDF to make woodworking jigs often.  Very stable base. 

In fact, I have an MDF (Rose Engine) lathe!  Here is more information on it :  http://www.rogueturner.com/root/MDF_Rose_Engine.html

Kind regards,
Rich

[kwakster]

@Ken: the dimensions of my own MDF strop with 1.0 micron diamond paste:

Length: 20.7 cm
Width 5.0 cm
Thickness: 2.1 cm
Total hight due to the rubber bumpers: 2.5 cm

I chose these measurements based on stropping Chef knives, as these have wider blades.
The edges on the long sides have been rounded just a little bit with fine sandpaper before i put on the diamond paste. (also useful for stropping serrations)
In the future i also plan to experiment a bit with diamond spray instead of paste.

The professional grade of diamond paste i use originates from this US based company: https://microstar2000.com/metallography/26/DIAPAT+Diamond+Paste

A cheaper option might be this US based company: https://www.techdiamondtools.com/
I bought a few different diamond powders from them in the past (good quality stuff i might add, with a long lifespan in my use), and i plan to try a few of their diamond pastes as well once my current supply runs out.
Owner Yuriy has proven to be a dependable dealer, and he is based in California.

[John_B]

Thank you for the information Gary.

Have you tried stropping at a point between the Tormek honing paste and the 1 µm paste you describe for final stropping?