Stropping: angle plus pressure

[LimpCroissant]

Gary W. Graley I've done that many times before as well. I know what kind of cardboard you're talking about, that thin yet firm stuff. I haven't done it in quite some time, but I used to put a bit of compound or even metal polish on a piece and it gave a very nice finish and seemed to get the edge back to sharp faster than my leather strops.

 

[The Art of Knives]

First Impression: Great Purchase from Knives Plus (recommended by a Custom Maker). Intuitive. Razor Edge.

 

[FlaMtnBkr]

I've always found that a slightly shallower/more acute angle with light pressure is the best place to start. There is definitely a feel when you have it just about right but I think that's when you're matching the bevel angle and it likely needs to go a little shallower.

But that is also with leather on a hard wood paddle. Using leather, on a microscopic scale and while matching the bevel angle, the leather is going to roll over the edge slightly if not using something that's rock hard. Which leather isn't.

I've also found that just leather or leather with a polishing compound, will mess up the edge more often than not unless you're sharpening a softer, more simple steel. If you are sharpening a hard steel or a super steel with lots of carbides, you're likely going to mess up the edge unless you're using diamond compound on the leather. A steel with lots of carbides is going to require many passes that you will likely mess up the angle occasionally unless you're using a system to hold a precise angle.

Since I'm usually using a "super steel", I either use diamond spray on hard leather on a wood paddle, held at a slightly more acute angle, or I don't even bother with a strop.

Good luck with it!

 

[kwackster]

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.

 

[Gottagofishn]

I’m sure many have stated this before but I spend 20% sharpening, 80% stropping. A BESS tester completely changed how I go about stropping (with Vadim’s book of course). And hundreds of tests…
I use a Rikon variable speed bench grinder with leather belts. I usually strop first with Tormek paste (3 to 6 microns), if it’s supersteel I then use a belt with a 6 micron diamond polycrystalline paste. If it’s a high end kitchen knife or a collectible I will follow up with a 1 micron polycrystalline and then a belt with .5 monocrystalline diamond and chromium oxide. I almost always finish on a leather belt with no dressing although If I’m under 80 on the Bess scores I don’t touch it again.
This process works on most mainstream knives. Some steel or tempers requires slight modifications to the process….
High end knives are done at 100 BESS or under….
Outdoor knives, I use a different process.

This is what works for me.

 

[Gottagofishn]

Leather vs Paste/compound
When I got serious about sharpening I bought a BESS sharpness tester. The very first thing I discovered was the impact honing/stropping makes. The next thing was how much the use of a paste or compound makes stropping. I do finish on a hanging or 1x30 plain leather strop as it almost always further drops the BESS score(good).… leather does have silicates in it but it is no where near as aggressive as some compounds.
I have tested and recorded ”stropping” BESS score results for about 100 knives. I recorded the BESS score after each pass on a strop and the results are consistent. If you are attempting to either remove a burr or just stropping the edge back, you will speed the process up by using some type of compound.
For most non-supersteels ground to 600 or even 1000 Tormek’s honing compound works very well in general, for me. I do use a variety though. In the book “Knife Deburring “ (link removed by staff) Vadim (RIP) discusses the size of the particle in the compound vs the grind “grit” is relevant so one size does not fit all or, there may be a better choice as in if it is a corse grind a larger grit like Zam might give better results.
If you sharpen, new or veteran, you will learn something from this book. The information is validated by election microscope images, Very enlightening. He discusses how a burr is really created as well as removal in different types of steel.
Good stuff…IMHO

 

[Mr.Wizard]

I’m sure many have stated this before but I spend 20% sharpening, 80% stropping. A BESS tester completely changed how I go about stropping (with Vadim’s book of course). And hundreds of tests…

Would you please describe how and why you spend this 80% (time, I assume) stropping? Are you using a progression of different strop compounds before the plain leather strop? Are you using powered grinding for the 20% sharpening work so that it is done quickly?

 

[Gottagofishn]

Would you please describe how and why you spend this 80% (time, I assume) stropping? Are you using a progression of different strop compounds before the plain leather strop? Are you using powered grinding for the 20% sharpening work so that it is done quickly?

To start with, I probably stretched the amount of time spent on stropping. But my point was, in the powered sharpening I do spend more time stropping depending on how the blade is ground, and the steel of course. If I sharpen with a 1x30 belt stropping usually takes the longest. I strop on a 1x30 leather belt with various compounds. I test every edge on a BESS and don’t call them finished until I reach a sharpness that is typical for the type of steel I’m sharpening. Sometimes the honing/stropping process can take a while to achieve the refined edge I’m looking for. I freehand with the stropping process and the smallest variation in how I am holding the knife can make huge differences in results. If I sharpen on the Tormek, controlled angle honing really speeds up the process… unless I take it to a paper wheel. That takes time to get everything measured and set up exactly and still often need to make adjustments during the process.
I do use a progression of grits although usually only one or two, but it takes time. My biggest time bandit is trying to achieve that ultra sharp finished blade. I believe none of my customers would notice the difference between a knife testing 100 vs 200 on the BESS, I just like sending them out as sharp as I would like.