Thread: Hone Testing Protocol

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.