new to stropping... questions

Since getting to know you folks here, I have been playing around with strops. So far I have played with balsa, hard felt and horse’s butt strops. The DMT .5 micron spray seems to do what I want on either balsa or felt, but I am liking hard felt the best. I can both feel and hear it sing when I have the angle right.

I have only used the horse hide bare. Guess I should have bought two hide strops so I could try it with and without diamond spray.

I have not tried Chromium Oxide or Cubic Boron Nitride. There is lots of information out there about using CrO and CBN on leather strops, but I can’t find much about using them on felt. What I am not finding is this: do you use CrO or CBN dry on felt, or do you make a slurry? (mineral oil, water, used motor oil... or what?)

A lot of what I read in different articles, on forums, etc, said that the diamond suspension/spray works best for kitchen knives. Since not all kitchen knives are made from the same metals, I doubt there is one “best” material to use with a strop. Your various opinions would be most welcome.

I am working with cooking knives. I do not want to put a wicked edge on them. The best description would be that I am trying to achieve a toothy but refined edge. An edge that has some strength and durability, even if it means a slight detriment to performance.

Nancy

 

Especially my vintage carbons (soft French and not so soft Sheffields) seem to benefit a lot from stropping with chromium oxide on split bovine leather. With Aogami Super (in Hiromoto) it only weakens the edge a bit, as with VG-10.

 

I am new at this... don't quite understand what you mean by weakens the edge.

When I looked as various knife edges, under magnification, after I stropped them, some had delicate irregular looking burrs. Is that what you are referring to as a weak edge?

 

Stropping seems to compromise edge retention with these steels. Must have to do with their carbides, I guess.
About what you describe - that fine irregular burr: is it a new accumulation of debris? Or is it an old burr that only has become visible after the cleaning up?

 

This morning I was stropping a Global and a Wusthof knive that I had sharpened. The Wusthof is one of their Asian styles and it has a 17 degree edge bevel. Global calls their steel CHROMOVA 18. I understand it is a rebranded name for Aichi AUS-118 steel. Rockwell hardness of 56 to 58. Wusthof uses DIN X50CrMoV15 with a Rockwell of 58. I can post the metal composition if that means something to you. Knowing the percentages of various metals is not meaningful to me at this point.

The fine irregular burr was on the Global knife. I don't think what I was seeing was debris or an old burr. When I stropped it on the bare horse hide strop it removed the irregular burr and left a much cleaner edge. I am too new at this to know if it was debris or the harder hide strop removed it.

I used the Wusthof knife this evening making dinner. Sliced and diced some onions, red peppers and green chilies. Also sliced some pork into thin strips. Mexican for dinner. The edge retension on the Wusthof Nikiri was very good when I finished. Will try the Global tomorrow.

Think I will try something I read about regarding stropping kitchen knives. That is to raise the angle 5 to 10 degrees. It is supposed to product a small second bevel, which is supposed to be a bit more durable.

 

I would first try an angle that's a few degrees lower than your stone sharpening angle to start with, instead of deliberately rounding the edge.

 

I think you are overthinking all this.

I use two stones, single plain horse arse strop and its plenty enough for a person who uses their knives, not look at them.

On the other hand, if you cannot get a satisfactory results with that, look into the problem

 

Trying not to overthink this. Originally started the thread because I really don't know anything about various strop materials, what to charge them with and... for that matter how to add the abrasive to the strop (dry, with water, with oil, etc). So, I have been experimenting, reading and asking questions.

I do knife sharpening for the average home cook. Professional chefs and knife knuts sharpen their own. The knives arive way past the need for sharpening touch up. Some have not been sharpened in ten years even though they are used every day. Just about everything needs a new edge bevel. Some have lots of dings and chips. I use a variety of machines to regrind the edge. My interest in stropping is to give the customer a more refined edge, beyond what the machine did.

I realize using machines is not highly regarded on this forum. But, people won't pay much for general knife sharpening. So, I can't spend hours sharpening these abused or neglected blades by hand on stones. Looking for something I can do after using the machines that improves the edge. My husband used a buffer. I have zero interest in using a machine that is likely to throw a knife at me at several hundred feet per minute. Stropping seemind like a good possibility.

Nancy

 

Nancy perhaps a very low RPM wheel with a leather belt would be the way to go. You could always add a diamond spray to it.

 

Look. I did plenty knives for other people with,I would say, 90 percent of the job was done with a belt grinder. Me too I dont want to waste time to thin by hand the neglected blades, but we talk stropping here, we talk having an edge already firm and established. So dont mix these two together.

If you have an edge, plain leather should suffice to make a difference.

Some knives, like the global, imho do not need stropping.

 

Slightly off-topic if you don't mind: I've got excellent results with a single microbevel on Globals, at some 30 degrees on a 2k Chosera. After that a few strokes on split leather.

 

@Benuser - not off topic to me! You gave me some much needed specific details.

I am finding the regular sharpening customers do like a microbevel. The knife is not as wicked sharp but the edge lasts longer.

@Jim - I have looked at some of the baby bench grinders with their 3 inch wheels and 0 to 10,000 RPM motors. Just not sure that is the way I should go. Since I have to free hand on them, I am likely to loose the machined edge. I am getting good results with a strop for fine tuning the somewhat toothy edge the machines leave.

I bought a Work Sharp Ken Onion machine. Need to play with it a bit. No idea how well it will hold up in somewhat commercial use.

 

The purpose of a microbevel is not so much about adding a bit of edge retention. It's more about allowing a crazy sharp edge behind it. In the case of the Globals that single-sided microbevel allows an edge I otherwise would put on much harder steels.

 

How? I am not sure I understand the geometry?

 

The Global steel will take almost every edge -- but not hold it. Just too soft. If you put a 25 degree inclusive angle on it, it will for sure take it, but barely hold. Think rather about a 35 degree inclusive, as with our soft German friends. A single sided microbevel of 30 degree though allows an edge behind it of some 20 degree inclusive.

 

Ahh, I understand better. I Need more education it seems.

 

No. I wasn't clear enough. The single-sided microbevel trick is well known. But here it is about using it in an early stage of your progression, not with the finest stone.

 

Global knives come out of the factory with a convex edge and a 30 degree edge bevel (15 per side). Rockwell hardness is 56-58

I am using the microbevel on both sides for customers who seem to beat their knife edges up chopping on the granite counter top and similar surfaces. The following is an image I grabbed off the internet. I am not changing the bevel that drastically, but it more or less explains it.



That does reduce the sharpness of the edge, but leaves a bit more metal behind it.

These are customers that used the softer German steel blades for years. They like the "out of the box" sharpeness of the Japanese edge, but don't have a clue as to it being thinner and more delicate. The harder Japanese blades are really chippy by the time I get them for sharpening.