Thread: testing sharpness

You know, I think any non-destructive sharpness test will do the trick, once you calibrate it to your shave tests and different razors.

I find them indispensable when honing because it is such a pain to get all setup for the shave only to find it is dull or whatever and have to head back to the other side of the house to the Hone Room.

It is true that the ultimate test is the shave test, but the hirsute tests can be made an arbitrarily close approximation to the shave test with experience and attention. For me, for example, I know I am in for a good shave if the razor cuts arm hairs in a certain way, at a certain speed, and at a certain height. I know this because I have done this test in basically the same way before each and every shave since I started honing, and eventually I figured out what the test did before good shaves, on a range of razors.

Pick one or two tests, stick with them, and calibrate them to your shave tests. That's what I'd do.

James.

Originally Posted by Jimbo

You know, I think any non-destructive sharpness test will do the trick, once you calibrate it to your shave tests and different razors.

I find them indispensable when honing because it is such a pain to get all setup for the shave only to find it is dull or whatever and have to head back to the other side of the house to the Hone Room.

It is true that the ultimate test is the shave test, but the hirsute tests can be made an arbitrarily close approximation to the shave test with experience and attention. For me, for example, I know I am in for a good shave if the razor cuts arm hairs in a certain way, at a certain speed, and at a certain height. I know this because I have done this test in basically the same way before each and every shave since I started honing, and eventually I figured out what the test did before good shaves, on a range of razors.

Pick one or two tests, stick with them, and calibrate them to your shave tests. That's what I'd do.

James.

Bingo!!!...

If I have to set a bevel, that usually happens at 1200 grit. My test there is how easily the blade 'falls' thru paper towel with a push/slice and if it will HHT a stiff boar's hair bristle. Splitting the hair is close but 'no cigar'. The 4000 stage can often resolve that but I like to get it earlier. Everything after that goes fairly quickly & polishes and further refines an edge that I know is sharp. As Bruno points out that aggressive edge gives way to a smoother edge at the Coticule and the Chinese 12K, my finisher - However post stropping with the pastes & then leather, the edge will usually treetop arm hairs a la Jimbo 'hirsute test'. Irritation is rarely an issue unless I've rushed the polishing stages but occasionally it's back to the Chinese 12K. Also some steels are harder than others and are just more work all round.
It's been said before the early grits are VIP but you may well get it sweet with the 8000.