glazing of stones

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Vicv

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Aug 22, 2011
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I've recently tried free hand knife sharpening. I got 220 naniwa SS, and a 1000/6000 king. The 1000 side seems pretty good but the naniwa and 6000 king side are both a beige colour i guess and they are both flat but covered in darker blotches so bad it appears as beige dots all over the surface. Is this glazing? I know the 220 will barely remove metal and doesn't feel very good. The 6000 just glides over a blade and doesn't feel like it's doing much either but will polish the edge a bit. They've been that way since new. Is this the way they come from factory? I just burned through three pieces of 80 grit 3M sandblaster paper till abrasion seemed about gone and an hour of my time and the 220 is mostly cleaned up till I gave up for the time being and I ran out of paper after about 10 minutes with the 6000. Now i plan to buy a diamond plate. Probably a course one. Is this normal to take so long to remove the factory glazing? Especially on very course quality sandpaper. I did the pencil lines and they're all very flat but no uniform colour. Thanks for any help
 
I cannot speak for the naniwa, but the King 6000 grit comes with the blotches - in use you will see that these are pockets where there are higher percentages of abrasives - they will turn black ahead of the rest of the stone as they load up with swarf. Waterstones in general do not glaze, but they will load up, they turn progressively darker as the swarf is embedded into the binder. As long as you give them a rinse and a swirl with a fiingertip every few minutes, they shouldn't even load up. Just don't let them dry out with swarf on them and its no problem. Be careful with the sandpaper lapping as this can leave embedded grit in your stone - an old silicon carbide, aluminum oxide, or Washita whetstone works a lot better.

BTW the 6000 grit is a polishing stone, it will give relatively little feedback and do a good job refining the edge. I highly recommend getting a Murray Carter video to get the most out of your waterstones in the shortest possible time.
 
Vicv said:
Rince every few minutes? Aren't you supposed to leave the mud on?
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Philosophy regarding mud and what its good for tend to vary a bit from source to source. In my opinion it comes in very handy at the lower grit values (220, 800, 1000, and to a lesser extent 1200) when grinding a new apex. The mud helps reduce the formation of burrs, and speeds the transition from a coarser stone to a finer one. I also find when doing a faster sharpening job I can carefully soak it up on a newspaper and use it as an excellent stropping compound if I'm not planning on moving on to a proper polishing stone. In general when it comes down to finishing the edge off, the mud prevents the best level of refinement at a given grit value (IMHO), you're better off with a clean stone. By all means experiment, but if you're still getting a feel for the waterstones my advise is to keep 'em rinsed for now.
 
It just seems the stones need a couple dozen passing before they start doing anything. I always thought the mud was letting me know it was working. I'll try keeping them rinsed off and see how it does.
 
Without knowing what type of steel you're working with, the 1000 grit King should be grinding away at a pretty good clip. The 6000 is a LOT slower - the 1000 is more of a grinding stone, good for re establishing a bevel, or changing a bevel, and will put a nice "working" edge on a blade. The 6000 is more of a polishing stone, will work much slower and requires a lot less variation in your holding angle. You should still see streaks of black swarf coming off the knife where it tracks across the stone. These streaks are what you want to keep from building up.

If you're using carbon steel or any of the more common stainless - 440C, 154CM, Aus8, even VG1 and VG10 the King stones should do a good job. As you get into the higher wear-resistant steels they reportedly slow way down.
 
Was trying to sharpen a mora #1 but there's something wrong with it I think. With factory edge(because I can't remove metal from it with anything) last night cut a piece of cardboard and chips all along the edge now. I've given up on that knife. The 1000 worked well at putting an edge(and even going to a steeper angle) on a wustof and CCK cleaver. Worked well on the carbon cleaver. Pretty quick too. The wustof takes longer than I'd like but eventually it worked. The 220 wouldn't remove any metal from either. Just makes the surface of the steel look cloudy but that's it. Even after 30 min of grinding away
 
I had a similar issue at first with my Norton 220 grit waterstone in that it would build a slurry fast and then the grinding rate would slow to a crawl. I started rinsing it almost continuously, but now use it with no water and just brush it off when it gets loaded up with dust - not sure if you have a similar issue with the Naniwa.

The Mora might be a different problem entirely. It sounds like you're grinding it to a completely flat Scandi grind - somewhere in the neighborhood of 20-22 degrees inclusive. It takes a real light touch to work a grind that thin, and its going to be somewhat delicate. You might want to ever so gently convex the apex a degree or three per side - bring it up to about 26-28 degrees inclusive and I think you'll have much better luck. I have one of those in my EDU rotation and it takes a great edge off these stones, but I did wind up convexing it ever so slightly right on the stone. If you broaden the edge too much it really detracts from the cutting ability on these knives, but just a smidge made a world of difference.
 
I am trying to get to a zero grind. Not to keep it that way but to remove some of what I think is bad metal from the edge. Then I'll lift the spine a tad and grind a secondary bevel on it. I'll try using it dry. I've just always been under the impression these stones need water to cut. But yes right at first I get a lot of black steel dust come off in the water. Then it starts making mud then cutting seems to stop. Even if I rince it it just doesn't do anything. I'll try the dry method
 
Vicv said:
I am trying to get to a zero grind. Not to keep it that way but to remove some of what I think is bad metal from the edge. Then I'll lift the spine a tad and grind a secondary bevel on it. I'll try using it dry. I've just always been under the impression these stones need water to cut. But yes right at first I get a lot of black steel dust come off in the water. Then it starts making mud then cutting seems to stop. Even if I rince it it just doesn't do anything. I'll try the dry method
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DON'T use your 1000 or 6000 dry, that bit of advice is just for the 220 and just to try - observe what's happening and discontinue if the results aren't there.
There are several things to consider - the blade will produce a lot more swarf on the stone when you initially transition from a coarser stone to a finer one, so what you're observing in terms of debris on the stone sounds correct. As the edge begins to match the grind from the stone you'll see less swarf, but it should still build up on there at a slower rate. The presence of mud will slow the grinding rate as well.
I generally just grind till the stone starts to run dry, then splash a little water on it, rub it clean with my fingers pushing most of the dirty water off the edges of the stone, and keep grinding. In some cases if I'm putting a fast edge on something and not planning to use a polishing stone, I'll collect the dirty water with a layer or two of newspaper instead of pushing it off the stone (1000 grit or 1200 grit stone). After I've reached the apex cleanly on both sides and reduced the burr, I'll wrap the paper around the stone and use it for a strop. Otherwise I do some edge trailing on the 4000 or 6000 grit stone and strop on dry newspaper to finish. Capable of dry-shaving stubble but still microtoothy.
 
Ya I've tried washing it off and such. It's just I thought the 220 was supposed to be fast but after an hour of grinding away I see no progress. It's very frustrating to the point I've just about given up on it
 
I had the same results from my Norton 220, finally tried it bone-dry just to see how it would work - now that's how I use it all the time. Its too coarse of a stone to load up badly, I just brush it off from time to time as I go and it cuts far better than it did when using it wet. Realistically for coarse grinding you could use any rough stone out there - a cheap hardware store stone does a fine job of roughing it. I use the waterstone because even dry it seems to cause less burring and edge gouging - easier to move on to the finer stones. I believe this is due to the abrasive being less "fixed" in the binder and pieces will more readily break loose rather than dig in excessively.
 
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