How To Sic stone flattening

awestib

awestib

Joined
Dec 29, 2008
Messages
1,647
Everybody,
I know that has been covered in the past - but!
I need to actually flatten my Norton Combi sic stone, not reviving the surface or anything, just flattening. I have neglected that for a while and now have to deal with it. I do have 90 grit and 120 grit Sic powder but I am not sure whether this is the best for flattening. I have read here on BF using the sidewalk with sand and water and I have done that in the past with variable success. Using back of a ceramic tile etc. or another coarse stone and I guess that all works to some degree. I used a "waterstone flattening stone" which did not work well, I actually used the Baryonyx Manticore also which did not work well. I have a well used XXC DMT plate that I use to flatten waterstones but I hesitate using it on the SIC.

Any update on this, any new experience here, any new tricks?

Thanks, Andy
 
FortyTwoBlades FortyTwoBlades gave this tip recently: search "no center hole diamond" at ebay, there are 8", 10", and 12" lapping disks that are super flat, fairly cheap, and big enough to handle your Norton.

Another option: search "sk11 diamond" at big river, I got the 150/600 grit one for $32, it is 8x3" so slightly bigger than a typical bench stone like Norton, and it helps with lapping. I've already used to lap my Arctic Fox stone.
 
The binder on a SiC oil stone is usually relatively weak, and the stone may not need much of anything special to knock grit off to flatten it. The grit sheds pretty easily, so there's less risk of glazing the stone or significantly changing it's grit characteristic. I've flattened a couple of mine just using another hardware store-variety aluminum oxide stone (stronger binder, doesn't shed grit like the SiC stone), and that has worked fine for me. You can even rub one SiC stone against another, for the same purpose. You can also get an aluminum oxide 'tile rubbing stone' at Home Depot, Lowe's, etc., which is just a very coarse-grit (60/80, something like that) aluminum oxide stone. I've also used one of those for the same purpose, and it worked as well.

I'd personally see no need to use an expensive diamond plate for such a job, as the hardness of the abrasive isn't really the concern on a SiC oil stone. It's the weak binder on such stones that makes the job easier, so all you're doing is knocking the grit loose; and that doesn't need much, to get it done.


David
 
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Draw some lines on it first w/ a felt tip marker. I use a area of flat concrete and the coarsest SiC grit I can get to put on the concrete. Using water I rub it, with different patterns. It's probably just the coarse side of your stone that needs it the most as that is more friable. Rub, check it, add some water and grit. Those stones don't take as long as a India. Maybe 20 minutes. I sharpen a good bit and have to do mine about every 2 years. DM
 
The Manticore can be used on aluminum oxide stones due to the difference in abrasive grain hardness, but when used in that manner it's not functioning the same way that a flattening stone or lapping with grit does. Flattening stones mostly have the grooves for the purpose of reducing contact surface, which increases pressure on the workpiece, assisting in breaking the bond. Lapping with loose grit does the same thing, only better. All of the little individual grits are acting almost more like ball bearings than as an abrasive of any kind, and are putting high pressure on their contact spots to break the bond of the stone down.
 
I would not hesitate to flatten with the XXC DMT. Fast and easy. Though I try to use a grit just lower than that of the stone for a flatten and refresh combination.
 
FortyTwoBlades said:
FortyTwoBlades FortyTwoBlades gave this tip recently: search "no center hole diamond" at ebay, there are 8", 10", and 12" lapping disks that are super flat, fairly cheap, and big enough to handle your Norton.

Another option: search "sk11 diamond" at big river, I got the 150/600 grit one for $32, it is 8x3" so slightly bigger than a typical bench stone like Norton, and it helps with lapping. I've already used to lap my Arctic Fox stone.
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Great idea. I found on one on ebay-Canada for 35$ + shipping. I might consider that.

Obsessed with Edges said:
The binder on a SiC oil stone is usually relatively weak, and the stone may not need much of anything special to knock grit off to flatten it. The grit sheds pretty easily, so there's less risk of glazing the stone or significantly changing it's grit characteristic. I've flattened a couple of mine just using another hardware store-variety aluminum oxide stone (stronger binder, doesn't shed grit like the SiC stone), and that has worked fine for me. You can even rub one SiC stone against another, for the same purpose. You can also get an aluminum oxide 'tile rubbing stone' at Home Depot, Lowe's, etc., which is just a very coarse-grit (60/80, something like that) aluminum oxide stone. I've also used one of those for the same purpose, and it worked as well.

I'd personally see no need to use an expensive diamond plate for such a job, as the hardness of the abrasive isn't really the concern on a SiC oil stone. It's the weak binder on such stones that makes the job easier, so all you're doing is knocking the grit loose; and that doesn't need much, to get it done.


David
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Thanks David - all good suggestions. My sic stone in question is 8 inch, I have another one in 6 inch which would make rubbing them against each other somewhat awkward. I don't have an AlOx stone believe it or not (at least not a larger Norton India type stone). I did find that tile rubbing stone on Canada HomeDepot for 12 bucks - that is the way to go I guess, however also 6 inch long ?!

22280"]The Manticore can be used on aluminum oxide stones due to the difference in abrasive grain hardness, but when used in that manner it's not functioning the same way that a flattening stone or lapping with grit does. Flattening stones mostly have the grooves for the purpose of reducing contact surface, which increases pressure on the workpiece, assisting in breaking the bond. Lapping with loose grit does the same thing, only better. All of the little individual grits are acting almost more like ball bearings than as an abrasive of any kind, and are putting high pressure on their contact spots to break the bond of the stone down.[/QUOTE]

That makes sense!

Thanks everybody for your suggestions.
 
maximus83 said:
That's an interesting data point. I wonder if this applies to AlOx stones as well.
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No, it does not. The India stones have stronger binders and I need to level the coarse side about once every 4-5 years. The fine side once every 10 years. Maybe a year longer. DM
 
David Martin said:
No, it does not. The India stones have stronger binders and I need to level the coarse side about once every 4-5 years. The fine side once every 10 years. Maybe a year longer. DM
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Traditional India stones, yes, but most Japanese water stones are aluminum oxide, too. All depends on the bond strength.
 
FortyTwoBlades said:
Traditional India stones, yes, but most Japanese water stones are aluminum oxide, too. All depends on the bond strength.
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Guess I'm going slightly tangent from the OP which is SiC, but: on the spectrum of AlOx stone bond strength, where do the newer Baryonyx AlOx stones fit in?
 
maximus83 said:
Guess I'm going slightly tangent from the OP which is SiC, but: on the spectrum of AlOx stone bond strength, where do the newer Baryonyx AlOx stones fit in?
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I'm not sure how to answer that? Aluminum oxide stones, like silicon carbide stones, can be made in a range from extremely hard to extremely soft. As far as how they fit within the usual range of stones used by hand for manual sharpening, we describe the bond strength in the product description for each stone. Different series all have different bond strengths in accordance with what context of sharpening is being targeted with that particular series.
 
What is the A-Z bond strength of the revised American Mutt versus the Manticore?
 
42, I own no water stones so I can't comment on those. My statements were generated from experience using Norton stones. Some old ones and some newer. DM
 
adamlau said:
What is the A-Z bond strength of the revised American Mutt versus the Manticore?
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Letter grades aren't standardized, and vary manufacturer to manufacturer. Hardness itself is the result of both the bond to grit ratio and the degree to which the stone is pressed during molding. As such, one could use the same grit in two different stones and arrive at the same hardness in each, but with the two being remarkably different in their cutting qualities.

The Manticore and the 2nd generation (and onwards) American Mutt stones are approximately the same hardness, but the Manticore has, overall, a much larger grain size. We consider them both a "hard" bond that can be used with aggressive pressure during shaping work.
 
The Ptarmigan is a medium bond and the Arctic Fox is a medium-hard. We don't currently have any plans to produce a medium bond ultra-coarse stone, as that would just fall apart due to the grain size and the kind of pressure that's best used at that stage of sharpening.
 
O use 100 grit sandpaper stick with tape on the paper edge on top of a balcony. It’s not too fast but is cheaper than diamond stones. Personally I don’t like the idea of use a more expensive (at least here where I live) stone to flatten a cheaper one.
I use it (sandpaper) on my sic stone 120/320 grit and ceramic ones.
For the 400~1000 ceramic stone I use the same grit sandpaper until is almost flat then I use a higher sandpaper grit like 400 to smooth the stone of 100 grit scratches.
 
I'd use the XXC DMT to flatten it (light pressure and I use a blob of dishsoap for a lube) and then recondition it with the 90 grit SIC.
 
HeavyHanded said:
I'd use the XXC DMT to flatten it (light pressure and I use a blob of dishsoap for a lube) and then recondition it with the 90 grit SIC.
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That's what I was going to do but now I ordered that "no center hole" diamond disk from China, 80 grit. I will wait for that and use it the way you suggested (soapy water) and then use the Sic powder I have from lee Valley to recondition the surface. Will keep you guys updated.
 
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