Thread: What grit would 0.5 Chrome Ox equal

I'm sure I've read this somewhere before, but cant find it now. Im wondering which would be the finer grit out of 0.5 Chrome Oxide on balsa and say a 12K barber hone.
I'm just doing some experimenting but I dont want to take a backward step.

The CrO is a finer grit and would be used after a barber's hone.

Here's a nice thread about estimated conversions and it looks like the .5 CrO would be equivalent to about 30k grit:
http://straightrazorpalace.com/honin...onversion.html

40_60k approxim

Sapton 30k is rated at 0.5 micron, but I am not sure if the CrO is rated on that scale. I have seen it being rated @ 60k but there was no mention of the scale used. IMHO it does not matter the grit rating because two different abrasives with same particle size will leave different feeling to the edge. One thing is sure CrO makes edges very nice and smooth after almost any stone.

Thanks fellas thats just what I needed to know.
Grant.

Originally Posted by mainaman

Sapton 30k is rated at 0.5 micron, but I am not sure if the CrO is rated on that scale. I have seen it being rated @ 60k but there was no mention of the scale used. IMHO it does not matter the grit rating because two different abrasives with same particle size will leave different feeling to the edge. One thing is sure CrO makes edges very nice and smooth after almost any stone.

Micron sizes are something I know little or nothing about. I just use practical application based on the rating applied to the stone or powdered abrasive or spray. IOW, if I'm doing a progression of paste on balsa I do 3.0, 1.0, 5.0, and 0.25. As Stefan says, IME the CrO will smooth out a harsh edge very nicely. A barber hone is a useful tool for adding keenness and I keep one in the medicine cabinet. I am not sure how much this has to do with anything but Randy and I were talking about the efficacy of a barber hone and the possible grit ratings of same.

Randy said that the reason barber hones, in general, cut so fast is the density of the abrasive. More abrasive per square inch than say a 12k stone. So even if the micron size is equal, or if it is coarser on the barber hone than the waterstone, the amount per sq inch is so much more, that the BH will whip up an edge way faster than a 12k stone.

What I'm wondering is if a leather or felt pad with a generous coating of diamond paste, spray or CrO as opposed to a light coat would also be more effective ? Seems like it would because of the density of the abrasive would be increased as on the barber hone. So is more better or is there a point of diminishing returns ?

Grit and mesh are just another way to describe the same thing, i.e. the size of the abrasive particles, but just going inversely, i.e. smaller particles larger grit.

That by itself is meaningless quantity for sharpening razors because how steel will be removed depends not only on the size, but just as much on the material and the shape of those particles, as well as how they are bonded to the surrounding matrix.
And since particle size is pretty clear and straightforward and can't be lied about, most companies like to use 'grit' because they can put any number they feel is justified.

So that's the long way to say that depending who you ask 0.5u chromium oxide can be anything from say 30000 to 60000 grit.
So you should instead ask the more meaningful question, what does it do, and at what stage of the honing it can be useful. And the answer is - at the finishing stage.
To really find out what it does you need to experiment using it instead/before/after your other finishers.

You can't do real experiment unless you do backward step as well. You not only shouldn't be afraid of that, but actively seek it, otherwise there is no way to know which way you are moving, and if you're moving at all.

Originally Posted by JimmyHAD

What I'm wondering is if a leather or felt pad with a generous coating of diamond paste, spray or CrO as opposed to a light coat would also be more effective ? Seems like it would because of the density of the abrasive would be increased as on the barber hone. So is more better or is there a point of diminishing returns ?

I haven't experimented with diamond, but with chromium oxide I know the answer - too much of it deteriorates the edge, instead of improving it. I believe it's because the abrasive particles are very weakly bond and form clumps which destroy the edge, which doesn't happen on a barber hone where they are really tightly bond and are not released from the surface.

Originally Posted by gugi

I haven't experimented with diamond, but with chromium oxide I know the answer - too much of it deteriorates the edge, instead of improving it. I believe it's because the abrasive particles are very weakly bond and form clumps which destroy the edge, which doesn't happen on a barber hone where they are really tightly bond and are not released from the surface.

Funny you mention this gugi. We have been told the same thing by our chemist on the diamond spray. He said that anything over 15 carat could have that exact negative effect in that the particles do exactly what you describe.

Have fun,

Lynn