What are your personal methods to test, a new to you, stone? Do you hone a particular test razor? Check scratch patterns under a microscope? What do you do to learn how to get the most out of the stone?
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What are your personal methods to test, a new to you, stone? Do you hone a particular test razor? Check scratch patterns under a microscope? What do you do to learn how to get the most out of the stone?
I'm also interested in hearing what the more experienced members have to say. I have a few naturals but feel I have yet to unlock their maximum potential.
After lapping the stone flat I do all that you say and more. The more observations I make the more I know the stone, my favorite thing is to watch the water go from being pushed along the stone by the blades edge to running up the edge towards the spine while at the same time feeling the blade suck into the stone as steel matches stone, at this point there should be little to no water sneaking beneath the blade.
Well by new stones for me it means hones that nobody else has ever honed on because of my rockhounding habit. I am looking at or for several things. I want to know how fast a hone can cut, I want to know how fine it can finish, I want to see how far I can go without the edge degrading, I want to know how the edge feels on my skin. I have a series of razors that I typically go to. I start with a fresh 1K bevel set. I go to my new hone and try water one and watch the polish. I go with a moderate or heavy slurry and see if I can progress the edge to a finish with dilution. I use edges finish on known hones to see how the scratch pattern compares. The big final is I shave or at least a small test shave right off the hone. All of these things combined with my 60X loupe tell me quite a bit about the hone, and I do it these things more than once for the most part and see what I can do with the hone. Some of them I send off to other people that are into hone experiments and get their opinion also. If it is good I may sell a few here and there. For the most part it is for my own curiosity and exploration.
I do pretty much the same as Shaun. First test for me is usually a cutting speed test just to see where in a progression the new stone might fit. I start from one of 3 places depending on how fast I think the stone will be. If I think it's very fast to the point of possibly being able to set bevels I will roughly set a bevel with a very worn DMT 325 and count laps to full 100% cleanup with the test stone. If I think the stone will more or less be pretty fast but not capable of bevel setting I will set a bevel with an Atoma 1200 and again count laps to 100% cleanup. If I think the stone will be more or less a finisher only I will baseline with a Shapton 2k Pro or a Suehiro 5k depending how fine the stone is and again count laps to 100% cleanup. I keep a notebook with this info for all my natural stones to compare them.
After this I know where best to fit the stone in a progression and I test a few edges on slurry only varying slurry concentration, a few edges that are started on slurry of varying concentration and diluted to straight water, and a few straight water edges. Straight water edges I take to an 8k Shapton Pro or 12k Shapton Pro previously, depending on the test stone's speed on straight water.
I'm a simple soul - I whack as many razors over it as I possibly can and apply appropriate tests.
James.
The same I use to test an edge on any stone. These are in order of progression (note that after establishing a bevel I mainly use coticules):
(1) Dragging the edge carefully across a wet thumb pad (looking for that sticky feeling) and shaving arm hair at skin level for establishing a bevel
(2) If I get no results, I use a marker test to see if the entire edge is in contac with the hone
(3) I check how the edge undercuts the slurry/water on the stone
(4) Dragging the edge above my arm, see how well it cuts arm hair
(5) Using hanging hair tests I judge how well the razor cuts hair along the entire edge (although honestly I skip this half of the time, because I'm impatient, stubborn and overly confident). Does the hair 'vibrate' across the edge, does the edge split the hair, does it catch and cut it or does it cleanly cut it with absolute minimal effort?
These are the tests I use because they make sense to me and they work for me. It takes quite a bit of guess work out of it.
You have asked two very different questions here, "How to test a new stone." & "How to hone a particular razor."Quote:
Originally Posted by joamo
I'll answer the stone question. I learn all I can about the stone first, by reading & asking others about it. I learn what level in the progression that it goes in, then I try to get a successful outcome with a different variety of steels & grinds.
The stone question is the one I'm asking about. The other questions are more to ask if that is a method you use, I can see I could have worded that more clearly.
Not a problem,,, just wanted to make sure I gave you the best answer for the right question.
Thanks, I've edited the first post to clarify.
If I am looking at a natural, it would be to finish.
First, I hone on a12K Super Stone. I then mark both sides of the blade in the middle and re-hone the toe half on the test stone, keeping the mark at the edge of the stone.
I compare the stria to the 12k for uniformity and size. This will give you a good idea of the stones potential.
If lower than the 12 I will sometimes do it again on an 8K, few are finer than 8K.
A quick shave test removes all doubt.
I don't have a protocol so much. My first check if a stone is a natural is to make sure that it's flat, and then after that it's to put a razor with a bright bevel on it and see how it goes. If the stone cuts coarse, I burnish the surface with a chisel, and then I put the razor to it again to see if any iron swarf shows up in the water (if it's a natural finisher on an already honed razor, hopefully not).
Then I work the edge and strop it on bare leather and check the sharpness. If arm hair shows that it's in good shape, then I shave face with it. If it's weak, I put it on the linen (no abrasive) and then strop it again and see if it makes a difference (usually not much).
If it's still lacking, then I run it through another cycle of strokes, but with firmer pressure, and then light pressure, and then linen and leather again. Stones that cut really slowly don't mind a bit of extra pressure on the finish, and usually are not very sensitive to the stroke direction.
If the problem were the opposite and the stone cut too coarsely, I would do a finish of the edge, then linen, then five light strokes with the stone, then linen, and repeat that until I had an edge (that's essentially the linen setting the edge and not the stone, but that is a practical method of sharpening, one that will coax a better edge out of a coticule, and a shaving edge out of a washita). If I can confirm it works like that, then I can at least describe the method to someone if they want to finish with it, anyway.
One thing I make certain to do is use one of my razors that is known dead straight and already sharp (i never use tape, so that variable is out). If a stone is interesting enough, I'll do the prior washita-ish test. If it's a boring stone, then I'll just call it junk, because there's no great virtue in a finish stone that can't finish, especially if it doesn't cut fast, either.
On natural finishing stones I don't even remotely try to estimate a grit. I look at the bevel at 150x illuminated with raking light only to check scratch depth. Shallow scratches to the point that they don't really cast any shadow at 150x with oblique lighting is usually a pretty good indicator that a stone is capable of a decent shave. Whether it's capable of a really comfortable/great shave can only be determined by the shave test. I have had natural stones that "look" like they should be classified at 5k that shave amazingly well.
I do a version of the marker. I have some test razors I dip in tool black, then hone. It makes it very easy to see the edge. Also I the slurry is black so I can see exactly how fast or slow the stone is cutting even with my old eyes.