Poltava Metallic Bonded CBN Sharpening Stones Review.

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wade7575

wade7575

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I have order a few times before from Gritomatic and I have always been pretty happy with everything I have purchased,I first purchased the Venev Industrial Diamond stones for my K02 knife sharpening system and I got the Venev stone's because they have diamond mixed right in with the grit and figured they would sharpen S110v steel faster and better as I have a lot of Spyderco knives in S110v steel.

I had emailed Konstantin the owner of Gritomatic a few times and talked to him about the kind of steel's I have to sharpen and he told me that he was getting in some Metallic Bonded Diamond stones and Metallic Bonded CBN stones to test and when I ordered a second set of the Venev stones he threw in a 120 grit Metallic Bonded diamond stone and I tried it and really liked how well worked so when he finally got in his next shipment from Poltava Diamond Tools I decided to go with a full set of the Metallic Bonded CBN stones witch there are 50,120,400,1000,4000,8000 grit.

All I can say is these stones should be called for a brand name Rabid Piranha's because that's the best way I can describe them and to call them just Piranha's would not do justice as to how fast they cut.

I started off with my Spyderco Paramilitary 2 with S110v blade steel and used the 50 grit stone first and it really removed metal fast and I mean fast,I counted how many strokes I did and when I sharpen and I do full stone length pull's back and forth while moving down the edge towards the tip and back again to the ricasso and it was a total of 16 strokes and I flipped the knife twice in the K02,the 50 grit Poltava is so fast at removing metal I would not let anyone who has ever used a guided system before loose on a knife with the 50 grit stone because of coarse like most people a newbie is going to think more is better and really grind the metal way much and just shorten the life span of the knife.

The best way I can describe how the 50 grit Metallic Bonded CBN stone worked is to say that it just cut's threw S110v like it's nothing just plain and simply put it's easier then taking candy from a tied up baby,the grit also produced filing's that looked like long metal hairs that look like they were made by a power tool then a sharpening stone,the rest of the grit's also removed metal very very fast and all I can say is that you can sharpen S110v much much faster then with any other stones that I have tried and the only ones that come close are the Venev Industrial diamond stones and they are slouch either when it comes to sharpening S110v or any steel for that matter.I also stropped the edge with Poltava CBN Paste and I started with 10,7,3,1,.5,.25 Micron and I used Kangaroo leather strop's on my K02 that I made myself.

One thing to mention about the stropping paste I found it to leave a thick waxy film on the edge of the knife when stropping and figured all I was doing was stropping the CBN paste as the layer was fairly thick,I asked Konstantin the owner of Gritomatic about how to apply the CBN paste and he said to just wipe it on but and I asked him about heating it up with a hair drier and he said not to as I may damage the leather,I got fed up with figuring all I was doing was stropping a waxy film so I gently heated up the strop's after I had applied the CBN paste just to point where the waxy stuff absorbed into the leather and sure enough it stopped leaving a waxy film on he edge,it still left a little bit until one side of the edge was done but I just wiped it off and after that it was fine.

The Metallic Bonded CBN Stones are 100.00 USD each and I know what a lot of people are going to say that's to money but no not really if you stop and think about,these stone's are bonded with Tin and Copped and they wear extremely slow,I know the Venev are also slow wearing stones are slow wearing as well but if I had to guess by how much abrasive is released from the Venev Industrial diamond stone's when compared to the Metallic Bonded CBN stone's I would feel comfortable saying that the Metallic CBN are going to last 10 to 15 times longer then the Venev stones if not longer yet so you do the math.

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This is the factory edge and what it looks like and this was the first time sharpening this knife.

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This is after using the 50 grit stone.

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This is after I used the 8000K diamond stone.

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This is the edge after I got done using all the different grit stropping paste's.

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My final comment's on these stones would have to be they are certainly worth the price if you want a stone that's cut's steel's like S110v at God like speeds,also as I said before I know people are going to gripe about the cost of these stones but don't forget they aren't going to wear out anytime soon when compared to other stones and I know some are going to say the same thing about Shapton Glass stones but I have the Shapton Glass as well and find the to be useless and frustrating on steels like S110v and make a task that's supposed to fun into something dreadful but then again the Shapton Glass wear so long is because they have a very hard binding agent and cut slow because they are Aluminum Oxide.
 
I also forgot to mention I'm planning on sharpening a brand new never used Spyderco Military knife in S110v and I was going to shoot a small video and show ho fast the 50 Grit and maybe the 120 and 400 remove metal,but I'm not sure when that will be done hopefully in a few days.
 
Do you have any experience with other manufacturers of diamond stone ? Can you compare with them ? For me DMT is the peak of the world ..because till now I use only cheap ordinary stone .............
 
I have used the DMT and the Gold Series for the KME and these are much better,the problem everyone always forget's or just does not know about diamond stones and plates is that the diamond's are just held in place by some form of solder.

The problem with them being soldered in place is that when you are sharpening the diamond's are so hard they dig and hook into the steel and get torn out when you sharpen and then you do not have many diamonds left on the diamond stone.Where as with Metallic Bonding the CBN stone's I have the CBN particle's are better anchored in and are much harder to tear out.

For I look at it this way do these cost more yes but will the last longer then a DMT or Gold Series stone oh yes much much longer and I also get the added benefit that they cut way faster than anything else I have ever used.

I look at it from the standpoint do these CBN stones cost a lot yes but then again you are going to wear out many more set's of DMT stones before you ever wear these stones out and if you keep track of what you have spent on DMT's you are most likely going to end up spending a lot more overtime by the DMT's,I know most people are going to look at the price for a whole set of the Metallic Bonded CBN stones and gripe about it but you can either spend the money up front or spend the same amount overtime and most likely more and not getting the same performance.

I can stress enough however how fast the 50 grit cut's,if a person is new to sharpening and got a set of these at the same time as getting a new sharpening system I think there would be a few people out there damaging their knives with the 50 grit think more is better when it comes to how many more times they grind away on the edge and in this case less is definitely more.
 
How do you dress these metal bond "stones"? The conventional ways I know of to dress this type of tool won't work with them.
 
Is the cbn just on the surface or is it in a bonded substrate like the Venev stones? I have a the Venev stones for the kme and need to get more for the edge pro I have too. But wondered about the cbn stones that you speak of here.

I think if cost is a concern getting a few stones in the lower grits to remove metal and then switch to more cost effective stones could be idea. As long as you are able to remove the scratch pattern put in place from the cbn stones with the next stone in progression.

I would avoid apexing with the lower grits like 50 and or 100 grit with any stones. As it can cause edge problems on some knives. But do use them for fast removal of steel. Basically Don't form a bur with them. If you had no problem with that, great. Just word of caution. I've seen edges just ripped out from doing that on low grit stones.
 
There is no need to dress the stones and Flattening is not recommend by Konstantin from Gritomatic,I think if they did start to dish at all then you might be able to flatten them with sandpaper and wet sand them if you were really desperate to flatten them,that is why I use full length strokes when I sharpen and try to go slower and avoid dishing with these stones and the Venev.

Diemaker said:
How do you dress these metal bond "stones"? The conventional ways I know of to dress this type of tool won't work with them.
Click to expand...
 
The CBN is all the way threw out the stones and the reason I got these stones was for sharpening my S110v knives as I have about 7 or 8 Spyderco's with S110v steel and I have never found any stones very effective on S110v except for the Venev Diamond stones until I got these,the Venev are great stones and if they were cheaper seeing that they are only 3mm thick I figured on how long the Metallic Bonded CBN would last in comparison and decided to go that way,I always find that whenever I need something like a new set of stones and I put off buying them and then when I have to buy them I'm always short on cash.

Mo2 said:
Is the cbn just on the surface or is it in a bonded substrate like the Venev stones? I have a the Venev stones for the kme and need to get more for the edge pro I have too. But wondered about the cbn stones that you speak of here.

I think if cost is a concern getting a few stones in the lower grits to remove metal and then switch to more cost effective stones could be idea. As long as you are able to remove the scratch pattern put in place from the cbn stones with the next stone in progression.

I would avoid apexing with the lower grits like 50 and or 100 grit with any stones. As it can cause edge problems on some knives. But do use them for fast removal of steel. Basically Don't form a bur with them. If you had no problem with that, great. Just word of caution. I've seen edges just ripped out from doing that on low grit stones.
Click to expand...
 
Mo2 as far as the edge ripping off I don't think that should be a problem with these stones as they are sharp and cut threw the metal unlike some stones where I'd swear it's more like plowing it off.
 
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wade7575 said:
The CBN is all the way threw out the stones and the reason I got these stones was for sharpening my S110v knives as I have about 7 or 8 Spyderco's with S110v steel and I have never found any stones very effective on S110v except for the Venev Diamond stones until I got these,the Venev are great stones and if they were cheaper seeing that they are only 3mm thick I figured on how long the Metallic Bonded CBN would last in comparison and decided to go that way,I always find that whenever I need something like a new set of stones and I put off buying them and then when I have to buy them I'm always short on cash.
Click to expand...

Wait a minute , you have already written that you have DMT diamond stone ? Does this mean that DMT can not sharpen S110v steel ??????????
 
Yes the DMT can sharpen S110v steel but the problem is that the Diamonds tear off of and kind of diamond plate whether it be a DMT or Gold Series by KME or Atoma diamond plates.The reason I went with the Metallic CBN is because the CBN is anchored right into the Copper and Tin that has them bonded into place,the problem with diamond plates is that it's just some kind of solder that's holding them in place.

The DMT's can sharpen S110v but not as fast and like I just said in my comment above the reason for the Metallic CBN is that they last much much longer because the CBN will not tear out as easily.
 
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I just got a 50 grit version of these stones in today to try out. I expect that I will be getting a few more. Thanks for the review on these.
 
Hytekrednek I think you enjoy the 50 grit a lot as a stone to use on a new knife and to set or change the angle of the knife,I alway's sharpen my Spyderco PM2's and all their full face blades of similar thickness at the factory 15 degree's per-side,whenever I get a new knife always use my K02 and angle cube and go over the knife with a really coarse stone just to make sure it's set at what my angle cube is saying what 15 degree's is that way I know I'm going to be consistent all the time.

Also I'm planning on doing a video of the 50 grit for sure this Thursday if my camera does not give me any headache's,what kind of steel are you going to be trying the 50 grit out on.

I liked these stones so much I contacted Konstantin the day after I tested the stones and I wanted to order another full set but all I could get is a 50,400,1000,4000 grit as the 120 and 8000k are sold out right now but I will order them next month when they come back in stock.
 
Also just to let anyone know who maybe placing an order for anything from Gritomatic Konstantin has aluminum blanks that are brand new but have grit's on them that he does not use anymore and the grit's are engraved smaller then the new he's doing it now,the aluminum blanks are selling for 1 usd a peace,I got 24 my last order and another 24 this order as I'm planning on getting some Congress Tool's Silicon Carbide stones and I also make my own Kangaroo leather strop's.

I also got 2 Ruby Red stones that they sell from China because Michael Christy mentioned in a youtube video he really liked the Ruby Red stone and although he did not say it came from Gritomatic he use's the Venev stones so I'm going to guess the Ruby Red he use's is the same one they sell and that's where he got it from.

The blanks are not listed on the website as they can't be sold as brand blanks with now etching or engraving on them but if you go to Gritomatic's website and look up the contact info just send Konstantin a message about the blanks if you want some.
 
I will probably use the 50 on most good quality steel knives, but the first few are going to be cpms30v, vg10, and d2. If it works like I think it will, I will be ordering at least the 120 and 400 to go with the 50 to use for my coarse work for repairs and re profiling.
I also just got the 60 grit venev bonded diamond stone, but I will probably send it back to amazon for one of the other metalic cbn stones if all goes well.
 
Hytekrednek if I were you and could afford the higher grit's I'd get them as well,the 8000k does not seem to scratch as bad as the Venev stones,if you want to do mirror polished edge's just go over the edge with a shapton glass 8k stone and some water and talk to Ken Schwartz about what emulsion would have the same micron size as a shapton glass and put a drop of CBN emulsion from Ken on the shapton glass stone to help aid in the removal of scratch's.

I think even with the Venev 2000 grit stone witch is the same as a 15k water stone from Japan people make to big of deal when they read about how they will leave scratch's on the edge but they are not that bad at all and can be taken out the same way with a 16k shapton.
 
I just wanted to let everyone know hat I'm still planning on doing a video and posting it on youtube about the Metallic bonded CBN stone's I have been very busy lately,I'm hoping to have it up later this week or sometime over the weekend.
 
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