Silicon carbide stones

The steels I am specifically worried about are the S110V Manix I will get, my M390 Barrage, and my few Elmax blades. I try to avoid S30V, but I come across it. I had an unbearable time last time I tried to do S30V, but I also didn't have good stones. Will AlOx work on them well? Would I be better off getting CBN stones?

My questions sound stupid, but all my sharpening knowledge is for lower end (relative to S110V) steels and belt sanders (many of the belts I have used were SiC and they ground vanadium steels well, but the AlOx belts didn't).
 
Sharpening carbide packed steels is going to be best handled by diamonds. If you thought the Shapton stones were expensive then I don't think you will find a CBN stone in your price range.
 
Well CBN stones would be great except they would be prohibitively expensive. Again SIC is of slight advantage, but comparatively slight.

So SIC and ALOX work by abrading the matrix surrounding the vanadium carbides and not really cutting through them (working hypothesis). An excellent compromise to having a stone of solid CBN is to dope a stone of Alox or SIC with some CBN so that it acts as a bit of an accelerant. The SIC / ALOX cuts through most of the structure and the CBN or diamond works on the remaining 'hard stuff' additionally. By volume, the SIC or ALOX does a lot of the work and the CBN finishes it off.

Alternatively you could use diamond belts or CBN or diamond compound on a linen (or leather) belt to speed things up considerably, going to coarser grits of CBN initially up to the desired level of refinement. This works quite nicely on abrasion resistant steels. I've used CPM 4v , 3v rex121, M390, etc this way.

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Ken
 
dkb45 said:
When I started sharpening I used some puny 1.5x4 stones. 6" is more than big enough for me to use. I think I will try sandpaper to start with. I just never had good results, but starting with 80 grit could have been the issue, because it was leaving a ton of micro chips in the edge. The 80 I can get is also tan (making me think it is not AlOx or SiC).

Is an edge from 800 grit really capable of that level of sharpness without stropping (on a strop with compound) though? I have pretty much mastered the light touch, so that won't be an issue. Is that low of a grit really able to be that sharp?

Also, can a SiC stone be used with water? I don't really want to use oil if possible, both for mess and ease of transport (no special container needed for a dry stone). I know it will likely load up faster, but I'm fine with that.
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With a light touch you can get a very fine edge off of many vitreous stones that might not sound possible based on the grit value. The important thing is the shape the stone is in - any glazing or plugging and it will start to degrade in performance. Also, harder steels will generally achieve a finer polish from a rougher stone as the abrasive isn't digging troughs as deeply as it would on softer steel.

You can use water (water with a bit of dish soap is even better) but it won't be as good a choice as oil. Oil suspends the swarf and debris right off the stone surface, water only helps keep the stone from plugging - it can still glaze over time or if your technique has a lot of wear in one spot on the stone. With oil, the surface will actually improve some from the factory and stays in great shape indefinitely.

Martin
 
Agreed, oil does work better on Norton's SiC & Alox stones. Plus, I've come to think the hardness of vanadium carbides are stated higher than accurate on some sites. Because I've used Norton's fine India & SiC stones with no problems on D2, S30V and S60V. Thus, I've come to realize the stone is doing more that abrading the matrix around the vanadium carbides. It's actually grinding down the vanadium carbides. It's no problem to reprofile, work up a burr and grind it off using these stones. Granted diamond stones are a slight step up and leave a cleaner edge. If it will cut S60V it will cut S90V. Still, I'm accurately stating my experience with these various stones. DM
 
Well looks like I might be getting a full set of diamond stones. I figured there would be some stones that gave an edge like a high grit belt for cheap. I'm sure the DMT XF will be just fine at 9 microns, and if I want to go finer I can just get lapping film (?) which goes to a few microns (swear I saw a 1 before).

I really didn't expect stones to be so bloody expensive. Everything I'm seeing here is basically saying that the best bang for the buck is diamond stones. A full set from XC to XF is barely $100 (with 6" plates)
 
dkb45 said:
Well looks like I might be getting a full set of diamond stones. I figured there would be some stones that gave an edge like a high grit belt for cheap. I'm sure the DMT XF will be just fine at 9 microns, and if I want to go finer I can just get lapping film (?) which goes to a few microns (swear I saw a 1 before).

I really didn't expect stones to be so bloody expensive. Everything I'm seeing here is basically saying that the best bang for the buck is diamond stones. A full set from XC to XF is barely $100 (with 6" plates)
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The upside (for me) is, I've never regretted the investment in my diamond hones. I've increasingly found more & more use for them, even on simpler steels. They can be very versatile, if one is willing to spend the time & effort to get acquainted with them and use them properly (light pressure, keeping them clean). Mine went largely unused for a long while after I bought them, largely because I hadn't immediately been comfortable with them. Once I did, I'm reaching for them all the time, and they're still surprising and impressing me. :)


David
 
I'm at the other end of the spectrum: it's not that I dislike diamond stones as I have several and use them reservedly. It's that other stones offer better economy and will cut/sharpen any steel I use. So, I use them as my 'workhorse stone'. Then if I feel I need to, I'll give the blade a few passes on the coarse diamond and stop. A very, very thin amount of grit on a stone which costs double over a SiC causes me to shy away from purchasing it or using it much. Just looking at the equation. That's why my edc knife is not of S90V or the latest whiz bang steel. DM
 
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I just returned from going around to my hardware stores and checking their prices on sharpening stones. The DMT stone (DUO grit) so, only half the 2X6" stone has diamonds on it. Were priced between 57.99 and 56.99 that's for ONE grit. The SiC & India stones made also in USA, offering TWO grits and the same size stone. Were priced at 5.99. This was for 3 of the nearest hardware stores. Thus, I could purchase 9 of the SiC two grit stones with grit over the entire stone and try to wear them out. Then gift them to my relatives and give them and their grandkids a shot at it and I'd spend the same amount of money for one DMT stone. Even checking a decent online sharpening supply this DUO stone goes for 44.99 plus tax and shipping.
For one grit over half the stone. Makes good sense to me. When all 3 stones will sharpen S60V.... DM
 
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