First day with a strop! Pretty disappointing :(

D

Dekz

Joined
Oct 26, 2007
Messages
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I purchased this strop & compounds online and they arrived today:

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I was pretty excited to get my knife sharpening to the next level, but I didn't have any luck. I watched some videos online about properly loading the strop and I think I did it correctly.

First I tried my Sypderco Bob Lum Chinese Carbon Fiber (VG-10). I got it as sharp as I could with my Sharpmaker (sharp enough that it very cleanly and easily goes through receipt paper). I did a few passes on the strop (maybe 7-8 per side, alternating). The result was always that the knife was duller. So I would repeat the process; back to the Sharpmaker, and then to the strop again. I was never able to improve the edge. I thought maybe I was using too much pressure so I tried this over and over until I was actualy using less than the weight of the knife. Still no good.

The only good thing that came from this is that I think I improved my skills with the Sharpmaker. Using it alone I was able to get the knife shaving sharp for the first time!

I also tried my Benchmade 940 (S30V) but again the stropping only made it duller. I couldn't even get this one to shave via the Sharpmaker, but I think it has a fairly thick edge, it is not a great slicer.

Any advice would be greatly appreciated.
 
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It takes a while to get the technique down. Try less pressure and lower angle in general. Or try different angles and pressure and listen and feel for the feedback you get from the strop and compare that to the results you get. The way I usually strop is that I start with a (fairly thin) V-edge that does not have a microbevel and then slightly convex the primary edge on the strop instead of putting the microbevel on there. That way is easier for me at least.
 
As said...use a sharpie to paint the edge of the blade. Use just enough pressure to guide the blade and start at a lower angle than the blade is already ground to. As you strop, *look* at the black mark to *see* where you are in relation to the edge. Raise the back of the blade a bit at a time until you can clearly *see* that you are working the edge.

Once you figure out the process, you will be amazed at how easy it is to do and how easily you can *keep* your blade sharp instead of running it to dull and reprofiling.

FWIW, the black is your workhorse and will get the hairpopping edge you want...the white is polish only. Don't even bother using it for now.

After you figure out the process, you can use the white to refine the edge, but for now it only confuses the process.
 
Try it without any compounds. I just use bare leather and it works great.

Not to sound like an @*%, but are you dragging your blade across the strop (backwards) or in a "slicing" motion?
 
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Monofletch said:
Try it without any compounds. I just use bare leather and it works great.

Not to sound like an ___, but are you dragging your blade across the strop (backwards) or in a "slicing" motion?
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I would change where I underlined rather quickly, I got warned for the same violation...just a heads up.
 
Monofletch said:
Try it without any compounds. I just use bare leather and it works great.

Not to sound like an @*%, but are you dragging your blade across the strop (backwards) or in a "slicing" motion?
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I agree, if you haven't successfuly stropped with bare leather, than its to soon to use abrasive compounds. I imagine your removing your edge with the loaded strop, don't give up. It almost seems magical what a strop can do for your edge!
 
Using a tool is a skill. It's not magic, a strop is a tool.
Adding compounds to the strop changes the tool. Learn to use the tool first.
Remove the compound using WD-40 (lightly!!!) lighter fluid, naphtha, etc. and clean it down to bare leather.

Lay the blade flat on the strop and raise the spine (only) about the height of one penny. Draw the blade away from the edge to the end of the strop without any downward pressure on the blade and 'feel' the friction. Now... do the same thing but raise the spine the height of TWO pennies and draw the blade away from the edge to the end of the strop. "Feel" the difference in the friction. Pay attention to it. I mean REALLY pay attention to that difference in friction. Now try it with three pennies and feel the difference... One of those 'settings' will feel VERY different from the other two, even to someone with no experience. THAT is the angle you want to strop with. Use your Sharpmaker to get the best edge you can, then raising the spine of the blade to the height that gave you that very different feeling, and NO PRESSURE on the blade except the weight of the knife itself, alternate 8-10 (only) strokes per side. Then try cutting your receipt paper again...

'nuff said.


Stitchawl
 
Stropping can be a little tricky. You must compensate for the slight depression made by the cutting edge touching the leather or you will continually round the apex of the cutting edge.

I for a long time used many Strops and multiple compounds to produce varying degrees of edge finishes, and while its exciting its not ideal IMO. The recommendation to use bare leather before trying compounds is one I couldn't agree with more. If you are able to finish well on the SM and reduce your burr to a bare minimum the you will find a nice piece of bare horse hide or kangaroo hide to impart a edge compounds only wish they could produce.

Of all the stropping and sharpening I have done I still find it very hard to beat the sharpness provided by a bare leather strop.
 
knifenut1013 said:
Of all the stropping and sharpening I have done I still find it very hard to beat the sharpness provided by a bare leather strop.
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Well of course! There aren't too many compounds sold that have grit sizes that go down to 0.01 micron the way natural silicates in leather do.

Horsehide has the highest concentration of them, but ALL leathers have natural silicates. Various tanning methods remove a lot of them or cover them up with grease, oil, or alum, and only vegetable/bark tanned leather retains them all, so it's the MOST effective, but all bare leather will produce a finer edge than any compound. That's why barbers have been using bare leather horsehide strops for hundreds of years.



Stitchawl
 
Stitchawl - coconut shell contains 3 to 5% silicate by weight. It rather difficult to strop on a spherical object but at least its hard surface keep convexing to a minimum. I stropped a few of my knives using coconut shell, was tricky but had about the same result as using horse leather. Coconuts from river delta region contain finer silicate.

OP - For my bm 940 (s30v, 30* inclusive), I encountered the same dulling affect when hone and or strop with abrasives below 3microns. Once I switched to Diamond & CBN 3um to 0.1um, my 940 is scary sharp and stay that way. Whereas edge produced by strop with Cr2O3 at 0.5um + bare leather, quickly lose its scary sharp, settled to a stable very sharp for a long time. Diamond & CBN are appropriate tools for abrading Vanadium Carbides.
 
If the edge won't shave off the Sharpmaker, it won't shave after stropping either. Edge angle on the 940 doesn't make that much difference in shaving ability at this point. The edge must already be very sharp, or moving to a strop is a waste of time.
 
Key words... "first day with..." :) Like stitchawl said, it's a tool, not magic... and needs to be learned. Technique on leather is different than technique on a stone.
 
knifenut1013 said:
I for a long time used many Strops and multiple compounds to produce varying degrees of edge finishes, and while its exciting its not ideal IMO. The recommendation to use bare leather before trying compounds is one I couldn't agree with more. If you are able to finish well on the SM and reduce your burr to a bare minimum the you will find a nice piece of bare horse hide or kangaroo hide to impart a edge compounds only wish they could produce.

Of all the stropping and sharpening I have done I still find it very hard to beat the sharpness provided by a bare leather strop.
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How do you feel about this conclusion from Dr. Verhoeven and his sharpening study:

The purpose of these experiments was to characterized the nature of the edges
produced with the waterstones and then to examine the effects of leather stropping upon
the edge quality. It was the opinion of the author at the start of these experiments that
clean leather strops would contain sufficient levels of natural abrasives adequate to
produce significant improvements in the edge quality. Therefore experiments were done
initially on clean leather strops. This was followed by experiments done on leather strops
coated with a thin layer of honing compound. The compound used here is called Micro
Fine Honing Compound supplied in the form of a wax impregnated bar having a deep
green color. The abrasive contained in the wax bar is a 0.5 micron size chromium oxide.

As discussed above, it was initially thought that a clean strop would contain22
enough natural abrasive material to produce a marked improvement in the quality of the
edge. As a result, several initial experiments were done with clean leather strops,
including an experiment with alternate 3 cycles of 4 leather stropping plus a single 6000
grit sharpening. In all cases the clean leather stropping proved ineffective in comparison
with the dramatic improvement found with the chrome oxide loaded strop illustrated...

Minor Conclusion:

Two independent sets of experiments utilizing stropping on clean leather showed
similar results. Such stropping action is not effective in removing the as-ground burs or
surface abrasion marks. Apparently, the natural abrasives in clean leather, on either the
hard or soft side of the leather surface, are not adequate to produce effective polishing.
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somber said:
How do you feel about this conclusion from Dr. Verhoeven and his sharpening study:
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I'll bite this hook - after seeing this quote/bait a few time. First of all, I deeply respect Dr Verhoeven's research. However in this case, his minor conclusion solely based on mismatched comparison between Cr2O3 0.5um and silicates at 0.05um-0.005um (50nm-5nm) was very odd in the realm of scientific discipline. Other factors were omitted: abrasive shape; abrasive progression( jumped from 4um to submicron or nano range was just large or ridiculously huge); etc..

Luckily there is an easy to test/feel the difference between edge with & without strop on bare leather. Facial hair shave with a straight razor (or a good knife) half side of the face where edge stropped with Cr2O3, then strop that edge with bare leather, proceed to shave the second half. Also with a super hi-res SCEM, we should able to see a delta between the 2 edges.
 
You can take a non shaving sharp edge to shaving, hair poping sharp with a loaded strop only. But it is much quicker and easier to do it otherwise.

It took me a bit of practice to reach the Eureka moment on my strop. If you feel like you are making your edges duller, you probably are. Very easy to do.

Have you practiced finding your "bite" edge angle. The angle at which the edge wants to start slicing the leather if you are going edge in? (some video's show knuckleheads actually cutting the leather). Don't cut your leather. Simply find that angle at which it wants to bite, and then drag backwards. Be careful to avoide rolling the edge as you take it off the leather. That has the effect of taking the edge back off too.
 
I had that problem as well for a long time. What works for me is to half the angle that the blade was sharpened at on the stones.
Magic marker is your friend.
 
The Verhoeven study teaches a lot, so long as one doesn't blindly accept it as the 'gospel' of sharpening. Good info in it, and very detailed in comparison to most other 'studies' available. But, the scope of the study was still very limited. To cover all of the possible variables (hundreds of different steels, heat treat recipes, abrasive types & sizes, tools, personal skill/technique/method, leather character/quality, etc.), a 'study' like that would never be fully comprehensive.

I've noticed, over time and with my own progress in sharpening, if an edge is further refined on the hard hones first, one can strop with effectiveness on almost any surface. Whether a strop actually abrades or polishes, or if it simply serves to gently clean away sharpening debris & fine burrs, it can still improve an edge significantly, if the edge is truly 'ready' for stropping.
 
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