Ummm... why doesn't anyone here use a two-sided carborundum stone?

hank_rearden

hank_rearden

Joined
Jun 7, 2002
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for re-profiling of course, since it's generally available in coarse and medium only.

Carborundum_-_109_Dual_Grit_Stone_-6_inch.JPG


i find it cuts basically anything made of steel with ease. all carbon spring and tool steels, vg-10, and 154 cm take only a few passes on each side to be re-profiled. carborundum also cuts zdp 189 aggressively, once the grains have "bitten" into the steel. s30v develops a burr very fast with it.

the problem is when i progress to something finer. a soft (natural) green stone will refine the initial coarse/medium scratches easily for carbon steel and ingot stainless. for zdp 189, i find switching to fine and then very fine Alox sandpaper gives me the best results.

s30v? that's where i start running into problems. i still haven't found a good cheap transition from medium carborundum. ceramic stones perhaps?
 
I love my combination SiC stones, use them for all kinds of base sharpening. For some tools is all they see, though I generally reclaim some of the mud and use it for a hasty stropping compound to finish off. Works on everything.
 
hank_rearden said:
for re-profiling of course, since it's generally available in coarse and medium only.

Carborundum_-_109_Dual_Grit_Stone_-6_inch.JPG


i find it cuts basically anything made of steel with ease. all carbon spring and tool steels, vg-10, and 154 cm take only a few passes on each side to be re-profiled. carborundum also cuts zdp 189 aggressively, once the grains have "bitten" into the steel. s30v develops a burr very fast with it.

the problem is when i progress to something finer. a soft (natural) green stone will refine the initial coarse/medium scratches easily for carbon steel and ingot stainless. for zdp 189, i find switching to fine and then very fine Alox sandpaper gives me the best results.

s30v? that's where i start running into problems. i still haven't found a good cheap transition from medium carborundum. ceramic stones perhaps?
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A lot of us actually do use a SiC (silicon carbide) stone. The 'Carborundum' moniker is a trade name for SiC, by the original inventor of it. Home Depot carries Norton's 'Economy' stone in their 'Crystolon' grit (which is Norton's trade name for their SiC). ACE Hardware carries SiC stones under their own brand, otherwise functionally identical to the Norton stone. I've also seen what appears an identical version of the Norton stone at Sears, under their own name (Sears and/or Craftsman brand).

A little bit of trivia:
The 'Carborundum' brand and Norton are both owned by Saint-Gobain Abrasives. See link below for the history of the 'Carborundum' name:

http://www.carborundumindustrial.com/CarborundumHistory.aspx

For S30V => DIAMOND will do much better; especially for finishing stages. SiC can handle the rougher grinding at coarser grits (like your Carborundum stone), because the vanadium carbides in S30V are essentially being 'scooped' out of the softer matrix steel. If your S30V edges aren't being refined much further than the 'Fine' side of your SiC stone, it may not matter much. At finer grits, as the vanadium carbides become relatively large as compared to the abrasive, then the hardness of the VC begins to impede grinding, because VC is harder than the SiC abrasive. You'll really see a difference when abrasive grit size gets down to ~5-10µ or smaller; that's when diamond at ~3µ and lower will really do a better job, and it'll show up in working speed, edge fineness and polish. Diamond and CBN are the only abrasives actually hard enough to cut vanadium carbides, which is why SiC won't work as well (it's less hard than VC). I at least consider using my SiC stones for most anything other than VC-heavy steels like S30V, for which I still use diamond at all stages, knowing it'll handle the carbides better.

(I've accumulated a total of 5 SiC stones thus far, in 8", 6", 4" and two pocket stones at 3", BTW. I like 'em. :))


David
 
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Hank, You've been missing it as I recommend them all the time. They are a very good stone. Offering much better economy than diamond. DM
 
I used my Norton JUM-3 to reprofile my S30V blade. The finer side is a good level for sharpening. I use my knife coming right off the stone. DM
 
David Martin said:
Hank, You've been missing it as I recommend them all the time. They are a very good stone. Offering much better economy than diamond. DM
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It is my most recommended stone for beginner freehanders. You might need a finer edge for some tools, but this stone is great for setting bevels anyway - and the edge right off the stone is no slouch. No matter what other gear one gets, that stone will not collect much dust.
 
thanks guys. and that was exactly my point. here in my place, a lot of naturally gifted free-handers turn out hair-popping edges on their knives from just the fine side. no "nonsense" with fine and ultra-fine stones, or lapping, or even stropping.
 
Yes, true in this Forum they obsess a lot with OCD sprinkled in over items. Still, the stone you show will give good edges on sooo many steels. Do you use it with oil or dry? DM
 
Hank, here is my stone from the same company. It's is an early one from 1962 a 2X4" and is much finer than Norton's JUM-3 fine side of 240 grit. It is more like 450 grit.Some folks don't think a arm hair shaving edge can be obtained from a 240 grit stone. DM
 
HeavyHanded said:
It is my most recommended stone for beginner freehanders. You might need a finer edge for some tools, but this stone is great for setting bevels anyway - and the edge right off the stone is no slouch. No matter what other gear one gets, that stone will not collect much dust.
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Agreed. As I know you recommend it. DM
 
mine is marked "Hamburg" embosed deep on the fine side. :rolleyes: i use water for all my sharpening, whether for machetes, axes, even my folders. the harder the metal, the lighter the pressure (especially when doing zdp 189 down to 10 degrees per side.)

420HC and 1095 spring are still the most fun steels to sharpen, IMHO.
 
I have a couple..
That being said, my prefered methods involve either waterstones, or dmt diafold, then stroping.. depending on the knife steel.
 
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