Why Norton Medium Crystolon instead of India Medium

D

dextersp1

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Jun 1, 2007
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I just purchased the Norton Fine India and Norton Medium Crystolon for a hiking and camping in the 4" x 1" x 1/4" size. It is a nice size.

I should have asked this question before I bought the Medium Crystolon.

Why is the Medium Crystolon recommended instead of the Medium India stone?
 
The Crystolon (Silicon Carbide) will wear faster than the India (Aluminum Oxide) but will also sharpen more quickly (aggressively) than an India stone of equivalent grit and will load less quickly.
 
I have a long-standing preference for medium India, but in this thread:

http://www.bladeforums.com/forums/showthread.php?t=496855

Phil Wilson makes a good case for Crystolon, particularly for sharpening high carbide CPM steels (e.g. S30V, 154CM.) Replies #24 and #28 discuss hardness of AO and SiC relative to carbides in steel, should be of interest. Note that Phil uses pretty much the same as what you have, performing finish sharpening on fine India ... so no question the stones you bought will work just fine and make a good combination.

Medium India does produce a superior edge IMO on tool steels and many stainlesses. Crystolon is faster-cutting due to both hardness and friability, but will wear/dish out much faster.
 
Dog of War said:
I have a long-standing preference for medium India, but in this thread:

Medium India does produce a superior edge IMO on tool steels and many stainlesses. Crystolon is faster-cutting due to both hardness and friability, but will wear/dish out much faster.
Click to expand...

Exactly my experience and the reason I went to diamond from the Crystolon.
 
Dog of War, I learned another trick from Wayne Goddard and Maynard who is currently doing a series of rope cutting tests on several different steels. They will be comparing sharpening methods with different stones/hones . The SC stone will dish out as you mentioned. A good way to keep it flat and clean is to lap it on a flat surface with lapidairy compound. You can get it from a rock shop and 100 grit works fine. I lap against an old cast iron drill press table I had laying around and use windex for a lube. When finished just rinse off with a hose and you are ready to go. Works just fine on India stones also. Phil
 
DoW and Phil Wilson,
Thanks for the replies. I was just trying to get an understanding the thought process.

I'm not worrying about the wear issue.

I was more interested in what combination would provide a sharp edge (for camping use) and longer lasting edge.

Am I correct in saying that except for the wear and faster cutting issues using the Medium Cystolon and fine India would produce the same edge as a Medium India and Fine India stone?

If that is not correct I think that is what most novice sharpeners would like to understand.

I read the thread recommended and it was somewhat over my head.
 
Phil Wilson said:
Dog of War, I learned another trick from Wayne Goddard and Maynard who is currently doing a series of rope cutting tests on several different steels. They will be comparing sharpening methods with different stones/hones . The SC stone will dish out as you mentioned. A good way to keep it flat and clean is to lap it on a flat surface with lapidairy compound. You can get it from a rock shop and 100 grit works fine. I lap against an old cast iron drill press table I had laying around and use windex for a lube. When finished just rinse off with a hose and you are ready to go. Works just fine on India stones also. Phil
Click to expand...
Thanks, Phil, in fact since discussing this I've been thinking about how best to flatten stones, including India. And I think I know exactly the stuff you're talking about, my father used to buy it for rock tumbling. Particularly on coarse SiC stones I think this might be the way to go ... I've made the mistake in the past of scrubbing two coarse SiC stones together, and it seems to really reduce the aggression or bite.

Also was meaning to ask you about using Windex when you mentioned using it as a honing fluid, I would have thought it would evaporate too quickly. I've used a mild soapy water with un-oiled SiC, but I gather there's something in Windex that works better. Will the cheap blue window cleaners work as well, or is Windex best?

dextersp1 said:
Am I correct in saying that except for the wear and faster cutting issues using the Medium Cystolon and fine India would produce the same edge as a Medium India and Fine India stone?
Click to expand...
Yes, I believe so, like Thom says. In that discussion I referenced there is some consideration given to problems you might see with India on certain high alloy stainless steels, but if I read Phil correctly, his experience has been that fine India works well for finish sharpening even those. So I think you're good to go!
 
Everyone seems to have covered this topic thoroughly. And I would leave it at that, but since I do most of my sharpening using small stones in hand, I may have a few things to add.

First off, My preference is to use the slip stone size (about 4"X2", not the multiform) they don't cost much more, and they don't pack much larger either (there beveled and fit together nicely in a pack), but it really makes a difference when your sharpening to have that extra inch of width. You can also use the two different radius edges for sharpening serrations. However those 1X4" stones work fine too.

You may not be concerned about wear but consider this, The rate of dishing on the crystolon is significant. This is not an issue if you have a big stone to work with, but if your removing allot of metal (like getting rid of a chip) on one of these small stones the dishing will be amplified, you'll see it dish before your eyes. In my experience this can affect sharpening, by adding a continuously varying dish to the fact that its difficult to hold a consistent angle with a small stone in hand, you can end up with a pretty ugly edge. Also when using these small stones its easy to cut into the corners with an imperfect stroke, or when sharpening a long knife, where the stroke is mostly down the stone and not much across (if you sharpen like I do), its easy to cut a groove in the surface of the stone, this is harder to do with India.

Hope this was helpful.
 
Ninjajoe, Good points, even with the larger stone if sharpening a longer blade like a 8 inch chef or 9 inch fillet knife if the stone is not perfect flat the corners will tend to catch as you described. The other point is that working the stone on a flat surface with lapidary compound will clean out all the embedded metal and allow it to cut easier and cleaner. Phil
 
Phil, your absolutely right. I too have been using the lapping powder (silicone carbide is it?) on glass after finding out about it on the forums, it really flattens and restores those India and crystolon stones (as well as my waterstones). Thats also one advantage of the crystolon I forgot to mention, they dont load up like the indias. Unfortunately I haven't yet figured out a way to make a portable kit with the lapping stuff, therefore when I'm camping or travelling I have to rely on the stones not dishing significantly during that period. I usually carry a scotchbrite pad and a little Ajax to clean the stones with, it doesn't work as good as lapping, but it is serviceable.

dextersp1, if your going with an India, you might want to consider the coarse. The coarse India is actually the same grit as the med. crystolon (about 150 US grit), and it might be a better choice for your coarser stone. I have used the coarse and fine India together, and there doesn't seem to be too much of a jump in grits to do this (anyone else have experience with this?). The coarse does wear a little however (still not as much as the crystolon), whereas the medium doesn't really wear noticeably. The coarse cuts faster, but I have taken a knife with a completely blunt edge to fairly sharp (shaving) with just a med India slip stone, so it is serviceable as your "coarse" stone.
 
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