Poltava Metallic Bonded CBN Sharpening Stones Review.

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True but diamond becomes softer then CBN once a certain temp is reached,also from what I have read CBN is more like Polycrystalline diamonds,also for sharpening knives and steels like S110v and Maxamet whether or not CBN is as sharp as diamond really doesn't matter because I found no performance difference what so ever from to the other with these stones.

Diemaker said:
The ONLY thing CBN does better than diamond is withstand heat, other than that diamond is the better abrasive. CBN is not the same as diamond, totally different, not nearly as hard or sharp.
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For those of us who are not using these on a grinding wheel producing heat, what advantage do they offer?
 
In theory they should have a more firm grip on the abrasive grains than conventional surface-bonded diamond and CBN stones, but also likely less grit protrusion, which would make them less aggressive at equal grit size. This is all conjecture on my part, though, as I've not used the stones in question personally.
 
So far i think the 120 grit is more agressive than the 50 grit kme beast, i profiled quicker than ever but there was debree that scratched but this is all learning for me and its a 40 dollar s30 manix 2.

Ive tried the venev bonded diamond for the kme, these cut much quicker.
 
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Roikyou said:
So far i think the 120 grit is more agressive than the 50 grit kme beast, i profiled quicker than ever but there was debree that scratched but this is all learning for me and its a 40 dollar s30 manix 2.

Ive tried the venev bonded diamond for the kme, these cut much quicker.
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Do you happen to know which grit standards are being used for both?
 
Thanks for the feedback. I'm interested in comparing these with the kme sized venev I have.
 
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I like both stones and if you want a higher stone the Venev go o the same grit as a 15K Japanese stones where the CBN only go up to 8K I have never compared the highest grits against each other but I have always been happy with both.
 
Grit size is only one of many factors that influence surface finish, cutting speed, etc. Important to keep in mind in such comparisons. :)
 
FortyTwoBlades said:
Do you happen to know which grit standards are being used for both?
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JIS 1998. I’m also curious if the stones clean up after use. With kme gold, theres a period where excess debree would be produced. After time, not so much and less issues scratching the blade, especially the 50 grit from kme. You would also noticed they are less agressive of course.
 
Talked with Konstantin via email and he lapped his metallic cbn stones before use. I have some Sic, 60, 120, 220 and 400 grit. Im going to use the 60 on the lowest grits, might work my way up and lap all stones before i try the next knife, see if its a little cleaner.

Anyone else lap before use as far as cbn, sic and bonded diamond stones?
 
wade7575 said:
I like both stones and if you want a higher stone the Venev go o the same grit as a 15K Japanese stones where the CBN only go up to 8K I have never compared the highest grits against each other but I have always been happy with both.
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How's the 1k finish? I'm stoked he is doing benchstones soon
 
I'm going to sharpen a Syderco soon in S110v I'll let you know in a few days,I normally go polished edge's with all my knives but with S110v I like the steel but hate it at the same time.I like S110v because it's just so dam wear resistant but I find you can't get the true scary sharp razor edge on it to last very long and it falls offs faster then a steel like M4 witch I find hold the scray sharp edge much longer for slicing.

What I will say is this for now I found going all the way up to the 8K Metallic CBN gives you results on M4 steel that very sharp and you get there in very short time,I have no regrets buying these stones for sharpening super steels I don't like half assing when comes to the knives that I buy and only like really good wear resistant steels witch in means your going to need good stones or else your going to be sharpening for a while.

I don't know if the 1K s going to leave scratch's that are to big and not refine the edge enough but if you got one and found that to be the case you could always use a 1K water stone to refine the edge a bit more as the Metallic Diamond and CBN tend to big and small scratch's.

For refining the edge you may want to contact sharpeningstones.ru and ask them about buying a few Gritalon bench stones from them,I swear on my life those Gritalon Silicon Carbide stones I got for my K02 are going to be my go to stones for refining edge's as much as possible they only go up to 4K in the Silicon Carbide but they are great stones for sure,they cut really fast even on M4 and they release their abrasive at a nice slow steady rate that is not to slow but not so fast that they will wear out really fast either,I'm more impressed with the Gritalon stones then all the other stones that I have ever purchased other then the Metallic CBN when comparing how fast they cut and just how they perform.

I know the Gritalons cost about 10 bucks Canadian in the edge pro format and that's best they are dirt cheap,I know I talked to Konstantin from Gritomatic about getting the Gritalons and the guy who owns sharpenstones.ru does not want to sell those stones to other vendors and I know Konstantin is going to try and talk to the owner of the Gritalon stones soon but the guy isn't really crazy about people cutting up the bench stones.

Don't get me wrong I'm not saying don't get the Metallic CBN I'm telling you that you may want to have other options for refining the edge after using the Metallic CBN,I also find you only need to rinse off the Gritalon stones as well and you don't need to worry about them loading because they don't load much at all and the little bit of metal that may remain in the stone will be released by the way these stones release their abrasive slowing and constantly,I also did a review on this site about the Gritalons look it up if you want to know a bit more about them.
 
If you look at my first post the grit's for the Metallic Bonded CBN are shown in a picture in the first post,they are rated at the factory in FEPA but Konstantin from Gritomatic rates them in Jis and another grit to I think right on the back of the blank.I'm not sure what grit rating system the KME's use.

FortyTwoBlades said:
Do you happen to know which grit standards are being used for both?
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I didn't yet on any other the new ones I got I never found the need but as the CBN wears down I will try refreshing them with Silicon Carbide powder.

Roikyou said:
Talked with Konstantin via email and he lapped his metallic cbn stones before use. I have some Sic, 60, 120, 220 and 400 grit. Im going to use the 60 on the lowest grits, might work my way up and lap all stones before i try the next knife, see if its a little cleaner.

Anyone else lap before use as far as cbn, sic and bonded diamond stones?
Click to expand...
 
Roikyou said:
Talked with Konstantin via email and he lapped his metallic cbn stones before use. I have some Sic, 60, 120, 220 and 400 grit. Im going to use the 60 on the lowest grits, might work my way up and lap all stones before i try the next knife, see if its a little cleaner.

Anyone else lap before use as far as cbn, sic and bonded diamond stones?
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Yes, on my resin bond diamond stones I lap the coarser grits, down to 110 micron, with 400 grit Sic, 8 micron and up I lap with 4000 grit Alox. I have tried all kinds of abrasives to lap with but found the 4000 Alox works just as well but removes less "stone" so they last longer. For general cleaning between lapping I use rubbing alcohol on a paper towel. The only thing that really wears my stones is lapping, not sharpening, so go easy on the lapping. I only have experience with what I make so can't speak for sure of other resin bond abrasives but assume they are all somewhat similar.
 
taped up this knives this time around, no issues with scratching. Worked with CBN this morning but it feels like there is a gap between 120, 400 and 1000. Just didn't clean up between grits as easy as other stones. The aluminum oxide (stock edge pro stones) on S30V clean up really well between grits. Thinking about adding bonded diamond to fill in the gaps. The 240, 400 and 800 seems like they would fill the gaps according to the JIS-1998 and FEPA-F charts. plus give me a little more experience with the bonded diamond.
 
wade7575 said:
I didn't yet on any other the new ones I got I never found the need but as the CBN wears down I will try refreshing them with Silicon Carbide powder.
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If you have access to iron chloride, you can make the water solution for chemical conditioning of copper-tin bonded stones. Iron chloride will "burn" top thin layer of metal and expose new abrasive particles. I have read that it's a better way of conditioning metallic stones than physical refreshing. We plan to add iron chloride to our product matrix after tests.
 
wade7575 said:
I'm going to sharpen a Syderco soon in S110v I'll let you know in a few days,I normally go polished edge's with all my knives but with S110v I like the steel but hate it at the same time.I like S110v because it's just so dam wear resistant but I find you can't get the true scary sharp razor edge on it to last very long and it falls offs faster then a steel like M4 witch I find hold the scray sharp edge much longer for slicing.

What I will say is this for now I found going all the way up to the 8K Metallic CBN gives you results on M4 steel that very sharp and you get there in very short time,I have no regrets buying these stones for sharpening super steels I don't like half assing when comes to the knives that I buy and only like really good wear resistant steels witch in means your going to need good stones or else your going to be sharpening for a while.

I don't know if the 1K s going to leave scratch's that are to big and not refine the edge enough but if you got one and found that to be the case you could always use a 1K water stone to refine the edge a bit more as the Metallic Diamond and CBN tend to big and small scratch's.

For refining the edge you may want to contact sharpeningstones.ru and ask them about buying a few Gritalon bench stones from them,I swear on my life those Gritalon Silicon Carbide stones I got for my K02 are going to be my go to stones for refining edge's as much as possible they only go up to 4K in the Silicon Carbide but they are great stones for sure,they cut really fast even on M4 and they release their abrasive at a nice slow steady rate that is not to slow but not so fast that they will wear out really fast either,I'm more impressed with the Gritalon stones then all the other stones that I have ever purchased other then the Metallic CBN when comparing how fast they cut and just how they perform.

I know the Gritalons cost about 10 bucks Canadian in the edge pro format and that's best they are dirt cheap,I know I talked to Konstantin from Gritomatic about getting the Gritalons and the guy who owns sharpenstones.ru does not want to sell those stones to other vendors and I know Konstantin is going to try and talk to the owner of the Gritalon stones soon but the guy isn't really crazy about people cutting up the bench stones.

Don't get me wrong I'm not saying don't get the Metallic CBN I'm telling you that you may want to have other options for refining the edge after using the Metallic CBN,I also find you only need to rinse off the Gritalon stones as well and you don't need to worry about them loading because they don't load much at all and the little bit of metal that may remain in the stone will be released by the way these stones release their abrasive slowing and constantly,I also did a review on this site about the Gritalons look it up if you want to know a bit more about them.
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Wade, I'd really like to see more pics of the 1k, 4k, 8k finishes

I can't afford all of them so I have to pick and choose
 
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