Stropping is a frustrating process for me. Sometimes it works, sometimes it doesn't, sometimes it kills my slicing a aggression, sometimes it dulls my blade I am sharpening. I am trying to figure out why. Most of the time I don't use a strop, and it isn't necessary most of the time to get a very sharp edge. What I am trying to piece together is why this happens. I am hoping to start a conversation about it.
The equipment I am using the majority of the time are:
Vintage Hanging Strop with Plain Leather, Plain Linen/Canvas, and Pasted Linen/Canvas (Enkay Green Stick Buffing Compound)
Flexcut 8" Knife Strop loaded with Flexcut Gold Compound
Wood Craft Stick, Jumbo and Small, Loaded with Oil-based Diamond Paste, 1.0 micron and 0.5 micron.
Plain Newsprint
Cardboard
Sharpen Techniques:
I will either sharpen a knife in a burr free method:
Cliff Stamp Three Step Method:
[
youtu.be]
or use a burr method and deburr on the stones, or use a burr method and use the strops to deburr:
Michael Chritsy, Full Sharpening:
[
youtu.be]
Stropping after using a burr free method:
This is what I am trying to accomplish, refinement of the edge finish and burr removal:
[
scienceofsharp.wordpress.com]
Unfortunately, I run into this problem:
Quote
jasonstone20
[
www.cliffstamp.com]
I have noticed that when I use a burr-less or burr-free method of sharpening, if I strop with abrasive, no matter the compound, no matter the substrate, the knife gets duller and slicing aggression is reduced. It is like the sharp apex is abraded away. This is with edges that are coming off 3u and up, like the DMT EEF, White Ceramic, Spyderco UF Ceramic, and Dan's Black Arkansas. If I am lucky, and only do 2 passes per side, the edge polish is increased and I didn't kill the edge, but it isn't sharper. If I burr sharpen, it works as long as I don't cut off the burr on the stone as best I can, then the abrasive strop doesn't really sharpen that edge. It works as long as I use it as the next step in my grit progression. Even then, it doesn't get any sharper than burr-less/burr-free sharpening, or just cutting the burr off on the stone. Using plain linen/canvas and plain leather, the edge doesn't lose slicing aggression, and push cutting is slightly increase, or at least hair whittling ability is.
and I got this response:
Quote
JSCT
[
www.cliffstamp.com]
Probably it radiused the edge.. Try to keep stropping angle minimal, control the movement..
No need to be fast, just few controlled precise passes with little force.
In some cases even u use smaller angle than on the stones, leather compresses and still
touched your apex.. So keep angle as low as possible to touch the apex..
Dont use microbevel before stropping..
[
www.cliffstamp.com]
Jason, If You sharpen on wetstone w slurry, slurry abrades your edge off constantly
(reason for removing the burr) However stone grind the bevel fast enough to keep it apexed.
This is different when stropping and having any excess abrasive or oily slurry with compound on the strop.
It also abrades your edge off, however compound cannot grind bevel fast enough to keep edge apexed.
So thats why u get a radiused edge.
Glue leather on the glass and then flaten the leather surface on 1000+ grit sandpaper
on the glass block same way like when flatenning the stones.
Clean it with hand from dust and remaining abrasive and repeat to wipe with oil
and cleaned cloth until nothing is being released from the surface.
Wash with water and detergent and clean wipe, let dry
and use unloaded after 6000 grit stone. Must work excellent smiling smiley
Which makes sense to me, so that is one problem looked into, although Science of Sharp shows that you can successfully strop an edge after microbeveling. Here is part of the mystery, why it dulls and edge sometimes and sharpens another.
Sometimes stropping kills slicing aggression, and sometimes it doesn't:
Slicing aggression still present:
Michael Christy cutting demo:
[
www.youtube.com]
Slicing aggression degraded:
Big Brown Guy cutting test:
[
www.youtube.com]
Then there is what Bluntcut calls a balanced strop:
[
www.bladeforums.com]
Steel Drake uses a similar technique:
[
www.cliffstamp.com]
This technique seems to lesson the chances of the blade dulling and the slicing aggression being degraded.
Discussion here: [
www.cliffstamp.com]
Science of Sharp also has some articles on why stropping works. His conclusions are in the main article, while his process is usually explained in more detail in the comment section:
What Does Stropping Do?:
[
scienceofsharp.wordpress.com]
The Pasted Strop:
Part 1:
[
scienceofsharp.wordpress.com]
Part 2:
[
scienceofsharp.wordpress.com]
Part 3:
[
scienceofsharp.wordpress.com]
Part 4:
[
scienceofsharp.wordpress.com]
The techniques I have used that have the best results are using a plain canvas/linen hanging strop, then a plain leather hanging strop, about 40 passes per side on each, using the Flexcut Knife Strop with Flexcut Gold Compound, two passes per side, alternating from heel to tip and tip to heel with the stroke, or using plain newsprint or cardboard, about 20 to 30 passes per side. Push cutting sharpness is increased, slicing aggression is kept at good level.
