Thread: Synthetic Hones Designed For Straight Razors ?

I wonder if the synthetic stones are moldeled on natural ones?

Originally Posted by JimmyHAD

I was googling around looking for info on coticules and what have you. I came across this here in google books. On page 168 the author says that because of the hardness of garnets the Belgian stone is on par with the Arkansas except that the rock is of such soft composition that tool edges pressed upon it cut the stone. He goes on to say that Belgian whetstones are suitable only for razor hones.

So I've never sharpened a plane blade or a chisel and I'm assuming that considerably more pressure is used ? If I am correct than these synthetic stones are designed with that in mind. The Escher and the coticule were favored by jewelers and maybe tool and die makers as well as barbers who were sharpening small tools with fine edges. Therefore a stone that had plenty of abrasive but was too soft (like the Belgian Coticule) for heavier cutting tools might be better for razors than what we have.

Jimmy,

I sharpen kitchen knives and plane blades with much more pressure because you usually need to remove enough metal to get to a non-stressed portion of the blade (depending on the tool). Knives and planes get treated much more roughly than SR's, and will have minor chips and shape issues that need to be addressed. As I said in another thread, I do not alternate strokes when sharpening kitchen knives, it's pretty much shape, refine, polish, done.

You could try searching for microtome honing equipment. I'm not aware of anything specifically for razors, but the edge on a microtome would be similiar to that of a razor so I'm guessing the sharpening equipment might be transferable to razors.

Alternatively, you could do a search on Patent Searching and Inventing Resources there's an awful lot of multi blade- razor honing ideas, but you might find something if you trawl through the results (I gave up after the first hundred or so, but you never know you might find something in there.)

Kindest regards,
Alex

I came across this from another old book,"
7. - " German Razor Hone. - This is universally known throughout Europe, and generally esteemed as the best whetstone for all kinds of the finer descriptions of cutlery. It is obtained from the slate mountains in the neighbourhood of Ratisbon, where it occurs in the form of a yellow vein running virtually into the blue slate, sometimes not more than an inch in thickness, and varying to twelve and sometimes eighteen inches, from whence it is quarried, and then sawed into thin slabs, which are usually cemented into a similar slab of the slate to serve as a support, and in that state sold for use. That which is obtained from the lowest part of the vein is esteemed the best and termed old rock." The German Hone is now used almost exclusively for razors, as being very soft, it is cut by any instrument applied at an angle, and not laid fiat down as a razor invariably is."


I haven't tried them yet but I hear the Naniwa Superstones are kind of soft. Maybe they are more geared towards razors than the harder synthetics ? OTOH, having brought up the topic because I was curious about it I have to say that the Nortons, Shaptons and the other synthetics do a great job on razors no matter what they were designed for.

Edit; The book is ....This section is from the book "Turning And Mechanical Manipulation", by Charles Holtzapffel. Also available from Amazon: Turning and Mechanical Manipulation.

Jimmy from what I've heard out of the industry, any product that is not custom made in respect of pressure applied, cutting depth, density, firmness of binder and type of abrasive, shape of grain etc, is an allround product designed for a possibly wide range of purposes. Hence not very specific.
You can ask for all those factors being custom tailored to your specific needs though. Usually they only work like this when they work for industries and everything else is a side product.

Originally Posted by Chimensch

Am I missing something here? Isn't a barbers hone a synthetic hone specifically designed for razors?

For maintaining an already sharp razor IMO, not for general honing/sharpening.

Originally Posted by 0livia

Jimmy from what I've heard out of the industry, any product that is not custom made in respect of pressure applied, cutting depth, density, firmness of binder and type of abrasive, shape of grain etc, is an allround product designed for a possibly wide range of purposes. Hence not very specific.
You can ask for all those factors being custom tailored to your specific needs though. Usually they only work like this when they work for industries and everything else is a side product.

Yes, I guess you're right Olivia. Ours is a small market for sure.

I checked into microtome hone.

The least expensive one uses "glass hone plates"

Hhhmmmm and lapping films.

Jimmy,

A2 is a high carbon high chrome steel with a high wear resistance that is air hardened (quenched). D2 is very similar except it is oil quenched. These are relatively newer steel compared to vintage blade steel. I do not know what them metalurgy of the straight razor steel is and I am sure it varies. My guess is that it would be close to an O1 steel, which is oil quenched w/ lower carbon and chrome content.

Honing is very similar to grinding. The object of the game is to have a bonding agent that will withstand the cutting process but break away when it dulls.

Here is a site that explains grinding wheels:
GRINDING WHEEL and ABRASIVES BASICS

and here is a quote from that site:

"Grinding wheel hardness

Hardness is rated from A-Z with 'A' being the weakest bond and 'Z' being the strongest. A weak bond is preferred for grinding harder materials while a stronger bond is desired for softer materials. A typical weak bond for steel would be in the 'F, G or H' range. A medium hardness would be in the 'I, J or K' range. And stronger bonds in the 'L, M, or O' range. Hardness is dependant on the grit type, the material being ground, the amount of stock removed, and a number of other factors.

Hardness grades are typically linear: If you increase the hardness by one letter grade (An H to and I for instance) it could give you double the wheel life. Many people mistakenly believe that such a move (from an H to an I) would only be marginal -- Don't be misled here: A move of just one or two hardness grades could have a dramatic effect on your process!

It is important to note that it is almost impossible to match one grinding wheel manufacturer's wheel hardness to another manufacturer: Differences in factory kilns, measuring instruments and the lack of a standardized hardness system do not allow for direct cross-overs. One company's 'G' hardness would be a 'F' with another and even a 'H' with another. We get calls all the time on this: We simply cannot guarantee one wheel to be the same as another. Even when our manufacturers switch their production to a different factory in another state or country we will see some variance. This can sometimes be considerable.

Structure or grain spacing

Structure is basically the spacing between abrasive grains. An open structure would be 12 or higher while a closer structure would be 6 or so. Here again, the structure depends on a variety of factors not the least of which is how difficult the material is to grind. One would think that a closer spacing would make a tougher wheel but this is only true to a point: With less bond holding the individual abrasive grains, the softer the wheel would be. Also, the same holds true for a very open structure: If the grains are wide spaced you have fewer grains to grind with but a greater amount of bond holding each grain -- This could make the wheel tougher. Grinding wheel engineers will typically adjust the BOND STRENGTH depending on the application.

Bond type

There are various bond types but the most common are vitrified and resin. Vitrified is basically a vitreous glass much like pottery or glassware fired in a kiln. Resin wheels are plastic resins mixed and cured at lower temperatures. Vitrified wheels are commonly used for bench, surface and tool room applications such as surface grinding while resin wheels are commonly seen in cutoff wheels, centerless wheels and superabrasive wheels (diamond & CBN). Newer bonds are Plastic bonded wheels based on high technology from companies such as RESEARCH ABRASIVE."

Hope this helps a little.

I have been seeing positive results using the Chinese 12k as a finisher on my German (hard steel) blades and using the Escher on my Sheffield (less hard) blades. Testing isn't complete and others may find their results to be different.