David Martin
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- Joined
- Apr 7, 2008
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jpm2, it sounds like you may have the aluminum oxide stone (it's more grey). The SiC stone is black. DM
I bought the 8x2 item 21165 also. It’s the same way. Their website lists both as silicon carbide, and they are more grey than black.jpm2, it sounds like you may have the aluminum oxide stone (it's more grey). The SiC stone is black. DM
I didn't realize you were in Europe. You might want to contact BORIDE directly and ask about international distributors. Incidentally I just learned that they now have sample kits in the 1/4" X 1" X 6" size, so you might consider a set if you already have to pay significant shipping. A set of T2 stones in F150, F220, F320, F400, F600 is $31.58.
Papilio, when I state a grit I'm meaning ANSI. A 240 SiC grit is not close to a soft Arkansas. You should find a grit chart that gives the different standards. I have all 5 of the Arkansas grade stones but rarely use them except on a axe. DM
I just bought a cheap stone from a hardware store $15 Aussie which would be under $10 US, made in China, it looks identical to the one above on the left. It came with no details, do you know what the grit sizes yours is.? And what oil do you use with yours.?Based on the stones I've bought at ACE, they've used either of aluminum oxide or SiC interchangably for a given stone under one part number. I have 8" and 6" stones in each material from ACE, and their packaging & numbering are the same either way for a given stone size (p/n 21165 for the 8" x 2"). The online descriptions as either aluminum oxide or silicon carbide don't really mean much to me anymore, and I don't give that any weight. Need to eyeball them firsthand for color (black or grey), in the store, and also gauge what abrasive they are (AlOx or SiC) based on how they work. BTW, this was also true for Norton's 'Economy' 6" stones for some time, as they originally were in aluminum oxide, then switched to SiC, with no change in packaging or part number (or price, for a while).
Pic below shows a few my oilstones in their oil bath storage. The two larger stones (8") at left are both ACE products bought under the same product number at different times, with the lighter one (grey) being aluminum oxide (more recent purchase) and the darker SiC (black/blue-tinged in that lighting), bought earlier. Both are good stones, relatively. But they do perform differently according to their abrasive type, with the AlOx stone being a little more limited in what steels can be used with it. As is common with an AlOx oilstone, it also doesn't readily shed grit like the SiC stone does. This is one of the more obvious perceptible differences in determining what abrasive type they probably are, in these hardware store-type stones.
Being that I have both types from ACE and can compare them side-by-side, I've noticed other subtle differences as well. The weight of the stones feels different in-hand (AlOx is heavier than SiC, in a given stone size), and I've also noticed the AlOx stones tend to feel cooler in-hand than the SiC stones, when they're dry. When the stones were brand new and un-oiled, I also even noticed they smelled different in dry use, with the AlOx smelling more like a natural stone and the SiC having a strange sort of pungent, carbon/burnt rubber character to it's odor. I know this all sounds weird, but these are the things I've noticed.
I just bought a cheap stone from a hardware store $15 Aussie which would be under $10 US, made in China, it looks identical to the one above on the left. It came with no details, do you know what the grit sizes yours is.? And what oil do you use with yours.?
Thank you for that, you have been a great help, i have never heard of an oil bath before, i might give it a try, thanks again, and you have a good day.I use any simple mineral oil with mine. That oil bath bin I store them in is filled with the pharmacy-grade (laxative) mineral oil, bought inexpensively at drug/grocery stores (got mine at Walmart in USA). I sometimes use Norton's Sharpening Stone Oil, which is a lighter, finer grade of mineral oil than the heavier, more viscous laxative stuff. Norton's oil is also a food-safe oil, by the way.
Not sure what grit spec my stones are. Most hardware store stones of this type often won't be marked other than 'Coarse' and 'Fine', and mine are marked as such on the packaging. In terms of the grind marks left on a bevel, the 'Fine' side of my aluminum oxide stone (at left in the pic) is probably around 400+ grit. The 'Coarse' side might be somewhere between 180-240 grit, in terms of the scratch pattern left. These stones always look relatively coarse by the eye alone, and might feel pretty rough in the fingers when they're brand new. But they taper off in aggressiveness pretty early, leaving a finish that usually seems 'finer' than what one might assume.
The unknown with very inexpensive hardware store stones is, they still might vary all over the place in the size & uniformity of their grit. With cheap stones, the best way to figure it out is just to use it and see how it does.
Thanks a lot. All my knives are carbon or stainless.I think post #24 explains my situation.
The 2 stones I recently got from ace hardware are the same color as the left above, and made in china.
The way it performs suggest its aluminum oxide. Works great for low/no alloy steels such as 10xx and simple stainless, not so good for others.
I like quality diamond stones but often prefer silicon carbide because it sharpens fairly quickly when I use some pressure, which I can't do with diamonds (although I've read pros and cons about this, depending on how much of the knife's surface area is in contact with the stone). I don't use oil because of the mess and don't have the time for waterstones.
I prefer the Razor Edge Systems coarse hone because it can be used dry. It's around the same grit as the Norton Crystolon coarse (120),
You might want to check out the DMT Double-Sided Diafolds.
Grit ratings are definitely confusing because of how little standardization there is, but charts such as the ones you've linked to help a lot to at least estimate how similar the different grit classifications are to each other. I used to try to make sharpening into an exact science, trying to find the perfect stone for each knife steel, but then I started to lose my enjoyment of sharpening, as well as it getting too expensive. Now I'm happy knowing I'm at least close to having the right stones for what I want to do.
Papilio, your charts are all over the place. Here's one from Sharpening Made Easy site that I consider accurate. https://sharpeningmadeeasy.com/grits.htm
In this your soft Arkansas is rated at 5-600. Which I consider accurate. You really like that stone but it is not a coarse stone. I wouldn't rebevel
with a 300 grit stone. As it would take too long. I would use a 100-150 grit stone in Al ox or SiC. DM
Thank you for that, you have been a great help, i have never heard of an oil bath before, i might give it a try, thanks again, and you have a good day.
Well explained, and seems logical and common sense. I used to have a small sharpening business many years ago. No internet or forums such as this back then, i learnt from a very young age by, getting books from the library, asking old timers about sharpening techniques, and trial and error to get my sharpening skills. This forum is fantastic for such pursuits, everyone is willing to give information and their help. I am always and still learning. Thanks again for your help and information.I used the oil bath, because these inexpensive stones come completely dry and not pre-filled with grease/oil as some others will be (Norton India, for example). These dry stones are very porous and will otherwise soak up a LOT of oil in use. So, the bath filled with the cheap laxative-grade oil seemed like it might help quench their thirst.
Here's one from Sharpening Made Easy site that I consider accurate. https://sharpeningmadeeasy.com/grits.htm
In this your soft Arkansas is rated at 5-600. Which I consider accurate.
Just wanted to say thank you for your unified grit chart. I keep a copy taped to my wall! It’s helped me so much as I try different sharpening Media and techniques. Thank you Mr. Wizard!In the grit chart I produce I use the approximation of 22 microns given by Norton Abrasives, which puts it between JIS 500 and 600, and even with P600 paper.
Mine states made in U.S.A. on the box. DMI think post #24 explains my situation.
The 2 stones I recently got from ace hardware are the same color as the left above, and made in china.
The way it performs suggest its aluminum oxide. Works great for low/no alloy steels such as 10xx and simple stainless, not so good for others.