Thread: How Important Is A Progressions Of Stones?

How important is a progression of stones?

I think it is very important to have a progression of stones in your sharpening routine whether you are using synthetic or natural stones. It does not need to be a numerical system but it should be based on grit action. Of course synthetics from company to company can vary in the actual grit particle range, a stated Norton 8K may me finer then a 8K Naniwa, Shapton or King and naturals can be difficult to figure out. But over time if you are able to create a ladder of stones (grit) to help you build an edge step by step, stone by stone as a foundation leading up to your final polish I believe your edges will last longer.

A longer lasting edge is important. A sharp edge feels good and that is what we are all looking for, but as the days or weeks or years pass the quest for a longer lasting edge surfaces as a rewarding goal too.

My reasoning for a progression of grits in providing a longer lasting edge in a nut shell is this. A sharpened edge is a damaged piece of raw steel at the very place where it meets empty air. Under a microscope it looks ragged and rough. This damage continues back into the interior of the steel away from the edge for a certain distance measured in microns, a very short distance, and less with finer grits. Off of a 60 grit grinding wheel this distance is greater, a 1000 grit a bit less and so on. Althought the distance is small the metalurgical structure of the steel has been impacted by the vibration and chipping of the abrasive and millions of fissures have been created separating the bonds of iron and carbon particles and undoing what beauty the blacksmith imparted in the birth of this polished hard steel.

This could be a kitchen knife or a lawnmower blade, but in the case of a shaving razor all damaged steel translates as a uncomfortable or ineffective shave. Of course we are not going to the grinding wheel with our razors, but the same type of tramatic stresses are transmitted to a finely shaped razor at the extreme edge by a diamond plate or a 1,000 grit stone. You may sharpen a blade with a progression of 1K-8K and shave with it, but I suggest that the edge will begin to desintegrate quicker than if you had inserted a 4K and a 6K in between.

The 8K above would have given you a useable shaving edge but underneath and behind that polished edge will remain the relatively damaged steel whereas the addition of the 4K and 6K would have helped to remove some of that steel allowing the final polished bevel to be based on sound firm material.

Now I agree that some very fine stones will quickly remove material and you can jump some grits and achieve a very sharp blade quickly without intermetiate steps, the temptation to accept the razor in the first initial stages of extreme sharpness will often overcome you dedication to continue working through the impacted steel. This brings me back to the durability of the edge.

Another factor of progressive grits is that in most cases your dearest stone will be your finisher, skipping steps will place more burden and wear on that stone thereby shortening its life expectancy.

In my opinion, more time spent at the stone in effective honing will result in a longer lasting edge. Alx

This is an interesting concept, but I personally don't think that I buy in to that line of thinking.

For example, there are some here who use only a single Coticule throughout the honing process. They set the bevel and finish on the same stone (it's actually a relatively quick process if you know what you are doing). Others, have a full progressions, and yet some others have multiple progressions.

I seriously doubt that because I use a Coticule to get shave ready that the edge will deteriorate faster.

Of course, I don't hone as a service for others, and some of those guys that do can provide a lot more insight into this. However, I think that inserting stones in the progression from 1-12/16K is more about reducing the amount of work on each stone and getting through the process more efficiently than it is about preventing edge deterioration...

Interesting thread

Hmm. What if I am using only one whetstone?

Yes, the way I was taught and have continued is with a progression of grits. If a honer was to jump from a 1k to an 8k without a 4k or whatever in between he would be a long time on that 8k to get an edge that was going to be satisfactory. OTOH doing the requisite work on the bevel at the 1k level will pay off at the 4/8 level. Plenty of choices of finishing stones both synthetic or natural to polish and refine the edge. Makes it interesting to work with various stones for finishing and compare the results in the shave.

Originally Posted by richmondesi

For example, there are some here who use only a single Coticule throughout the honing process. They set the bevel and finish on the same stone (it's actually a relatively quick process if you know what you are doing). Others, have a full progressions, and yet some others have multiple progressions.

I seriously doubt that because I use a Coticule to get shave ready that the edge will deteriorate faster.

This is not quite true either..

You are creating a progression also but you are doing it with the use of one stone and slurry... It however is still a progression and the same thing can be achieved on any other stone that can produce a slurry... I have done it on a Norton 8k just to prove a point.. I better add this for accuracy, you could just use one stone, and no slurry, it just takes a long time which I don't have to waste...

The difference is the accuracy of that progression, with a "ladder" of different grit stones the progression is rather easy and repeatable, with a slurry it is more of a learned experience....

Both get you to the top of the ladder (a sharp edge) but the climb is different...

Originally Posted by gssixgun

This is not quite true either..

You are creating a progression also but you are doing it with the use of one stone and slurry... It however is still a progression and the same thing can be achieved on any other stone that can produce a slurry... I have done it on a Norton 8k just to prove a point.. I better add this for accuracy, you could just use one stone, and no slurry, it just takes a long time which I don't have to waste...

The difference is the accuracy of that progression, with a "ladder" of different grit stones the progression is rather easy and repeatable, with a slurry it is more of a learned experience....

Both get you to the top of the ladder (a sharp edge) but the climb is different...

Excellent point. There is a progression in that sense, but the grit on the stone doesn't change rendering a lot of the argument in the OP invalid. He specified a progression of stones...

I am not even going it the longevity issue...

Way to many variables to even go there....

Originally Posted by richmondesi

Excellent point. There is a progression in that sense, but the grit on the stone doesn't change rendering a lot of the argument in the OP invalid. He specified a progression of stones...

Yes but the coticule is sort of an exception in that I don't know of another natural .... or synthetic single hone that can be used in the manner that a coticule can. What Glen said about there being a kind of progression in using slurry is a good point that I hadn't thought of .

OTOH, it is my impression, without trying to put words in the OP's mouth, that he was thinking mainly of synthetics in posting about a progression. I know I was in my first reply. After all it is in synthetics that we have defined grit progressions.

Originally Posted by JimmyHAD

Yes but the coticule is sort of an exception in that I don't know of another natural .... or synthetic single hone that can be used in the manner that a coticule can. What Glen said about there being a kind of progression in using slurry is a good point that I hadn't thought of .

OTOH, it is my impression, without trying to put words in the OP's mouth, that he was thinking mainly of synthetics in posting about a progression. I know I was in my first reply. After all it is in synthetics that we have defined grit progressions.

On a Coticule, you start with considerably wide grooves and make them shallower as you go along.
With a "ladder" progression (to borrow Glen's terminology), you start with wide grooves and make them smaller (and less deep) as you go along.

If a Coticule demonstrates anything, it's that you can get a good edge with rather larges particles. (5 to 15 micron in diameter).

But I don't think there's any significant effect on longevity, one way or another. If you want to thoroughly investigate such an assumption, you need to start with confirming the prediction in a real experiment with a large enough test group. If differences are found (which I seriously doubt), you can start speculating about the cause.

Merry Christmas,
Bart.

I've thought about this before. Instead of hitting the 1k, 5k, 8k, and finisher. What if strokes on each were reduced and a 3k, 10k were brought in, Say for argument sake, Naniwa's. Would it result in a better edge? Or am I wasting steel? Would it matter that much given how close each hone is? Looks like an experiment may be in order....I look at it like sanding steel on an Auto prior to painting. Progressive sanding along the way results in an awesome finish, and a great paint job. Same with sanding in woodworking...I realize of course in honing less is more. In other words, we want the best edge with the least amount of honing. We want to keep our blades wear free. Coticules are an entire different animal. The slurry would be your different grits for argument sake....

So, this is an interesting topic. I see his point.