Thread: Verhoeven Paper Question

Originally Posted by singlewedge

I read the section on stropping and hand honing. I guess after that I have several questions that were not either answered or addressed.

1. He stated that regular leather strops had no effect on smoothing the edge, but that a regular leather strop with Chrom Ox had a great effect of smoothing the edge. I assume that he used cow hide because he stated that he used commercially available leather from a shoe store. What about Horse hide, Latigo, Russian leather? Aren't they all leather? Is he stating that any leather, when treated with chrom ox, is better than leather alone?

He stated that clean leather doesn't significantly reduce burs that are the result of honing. He concludes that leather only has very limited abrasive power. I think he's correct. But I don't think Verhoeven is talking about shaving with his edges. Verhoeven measured the width of the edges on razors and commercial blades, finding typical widths in the 0.5 micron range. That leaves us with a 0.5 micron strip of erratic steel on top of the edge. I think that narrow strip is ductile enough to be alligned with friction. Clean leather seems to be just the appropriate surface for generating that friction. We all notice a clear performance improvement, coming off the strop. All my razors pass the HHT after stropping, while they loose that ability during the shave, only to gain it again with my next stropping. Stropping is just that, alligning steel and nothing else. If there was any metal removed, your strop would be loaded with that after extended use.

2. He never stated that he took the edges to a good cutting edge, shave sharp or otherwise, did I miss this section?

Verhoeven conducted experiments on knife sharpening. He refers to razors, and uses commercial razor blades where that fits into his experiments. But his methods and approach are aimed to knife honing. (hone on one side till a bur is present, next flip the blade and hone to remove the bur). He only measures the width of the resulting edges and leaves it there.

3. It seems that the waterstones with Nagura gave a better result than the man made stones. If this is true then why would I buy a Norton 4/8 besides the money?

If I understand it correctly, the Norton 4K/8K is a japanese style "waterstone", formerly made in the USA and recently in Mexico (if I'm informed correctly). Verhoeven's research favors those hones over diamond hones, such as those produced by DMT. (it is only fair to state that DMT uses monocrystalic diamonds, as apposed to most other brands of (polycrystalic) diamond hones, and that we don't know which type Verhoeven used)

4. Why was he going for a smooth bevel? I thought it was the edge that cut? Does the smoothness of the bevel translate to a better edge? Couldn't you have a smooth bevel and a rolled or otherwise blunted edge?
The smoothness of the bevel translates to the keenness of the edge. You can have a smooth bevel and a dull edge, but you cannot have a deeply scratched, rough bevel and a keen edge.

5. He stated that the Japanese stones worked best on 60 Rockwell stainless. Does anyone know what the Rockwell of carbon blades are?
The hardness of most high carbon steel blades varies between 55 and 62. Verhoeven limited his statements about waterstones to HRC 60, because that was what he tested with. He didn't say anything about the performance of those hones, on steel with a lower HRC, but it's safe to assume the results would be equally great. With HRC above 62, it's possible that diamond hones have an advantage, because diamonds are harder than whatever abrassive particles used in waterstones. I think Verhoeven only tried to be accurate with his statement about 60 HRC.

6. He used a compound bevel for his edge 9 degrees more on the 600 and 7 degrees more on the 1000. Is a compound bevel useful on a str8? How would one place a compound bevel on a str8? Electric tape comes to mind to adjust the angle.
Tim Zowada uses it on his razors, adding 2 or 3 layers of tape to create a very narrow microbevel. Other members, including myself, have experimented with it. I believe SRP member Jockeys made a honing video where he shows how it's done.

Thanks guys.

Best regards,
Bart.