rbscebu
Girls call me Makaluod
I have a few whetstones that I have accumulated over the past few years that I do not know the grit size of. I there a reasonably cheap method of determining the grit size of each?
How Can I Determin Grit Size?
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Steve56
Ask me about shaving naked!
Compare the scratch pattern to a known size with the highest magnification that you have.
You could also do HHT if the hones are the same kind (not thuri vs coti, or jnat vs synth) to do a ’go, no-go test’.
You could also do HHT if the hones are the same kind (not thuri vs coti, or jnat vs synth) to do a ’go, no-go test’.
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rbscebu
Girls call me Makaluod
I don't have other multiple whetstones of known grit size to compare them to. I do have lapping films from 30u to 0.3u. It might be an idea to compare scratch patterns against those of the films' under my USB microscope.
I would have to start with an edge that has been polished smooth with 0.1u pasted balsa strop.
What do you think?
I would have to start with an edge that has been polished smooth with 0.1u pasted balsa strop.
What do you think?
Pick a film that you think is close to the grit of the stone in question. Hone on that film, take a look, now hone on the stone in question. Did the stone in question improve, or degrade the edge? Find where the stone in question is bracketed by film on each side.
kelbro
Alfred Spatchcock
Rough estimates are plenty close for the work they are designed to do. The difference on steel from a 3000 grit abrasive to a 6000 grit abrasive is not that big.
Steve56
Ask me about shaving naked!
Loose grit and sandpaper use different grit scales than whetstones, si I doubt that would yield an accurate result by grit rating. Do a little research in grit ratings. I don’t know which one film uses. You’d need to compare micron ratings of the abrasive I think.
You should post a picture of the stones. If some members can identify what stone it is, you can get a rough idea of where in the honing process the stone would work best.
Slash McCoy
I freehand dog rockets
Yeah take an ordinary vintage of decent quality and unremarkable geometry, one that you don't mind putting a lot of wear on, hone to a good polish, and then go a couple dozen laps on the mystery stone. Test for sharpness using a standard battery of tests. TNT, TPT, tomato, paper slice, arm shave, treetop or hht, record results. You may not be comfortable placing them at a particular grit, but you can at least put them in order. If it isn't too much bother maybe do your films, too, so you see where the stones compare to your film progression. Also your known grit rating stones. This is gonna take a while. Maybe weeks, if you have quite a few stones.
Of course natural stones dont really have a grit rating. But you can approximate where they fit into your lineup. Do them with slurry and also with clear water.
Comparing scratches will get you nowhere.
Do what Bluesman has said. Improvement or not in the end result, assuming you are getting all you can with any one particular stone. Time and experience with stones is a must.
It generally will take a lot of experience to place a stone at a particular level to compare it to another known edge.
Do what Bluesman has said. Improvement or not in the end result, assuming you are getting all you can with any one particular stone. Time and experience with stones is a must.
It generally will take a lot of experience to place a stone at a particular level to compare it to another known edge.
I would never have thought of that but it sounds like a smart approach. Personally, I prefer film over synthetic stones simply because of the accuracy of film. I’ve never used naturals - why bother?
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