Venev 400 OCB and 15K Metallic CBN first look

[wade7575]

I got 2 Venev 400 OCB stones and a Poltava Metallic Bond CBN that's 15K as well from Gritomatic.

I sharpened a Benchmade Contego 810 with M390 blade steel,I started with the Venev 400 OCB then moved to the 800 and 1200 OCB stones I have as well and then finished with the 15K CBN stone.

I also stropped it with some 10 carat diamond paste as well,I only took picture's of the edge after I used the 400 OCB and the 15K CBN stone,I have posted picture's before that are still up on this board of the 800 and 1200 OCB stones and their scratch pattern's.

The 15K CBN stone improved the edge sharpness over the Venev 1200 OCB stone and has a very nice feel to it when cutting stuff,you almost get the best of a toothy and polished edge with the 15K stone.

400 OCB

15K CBN

 

[wade7575]

I'm also going to try etching the 15K stone as it felt a bit rough and I'm wondering if it's because of the way the stone was finished at the factory.

I'm thinking the Copper Tin matrix maybe a bit rough and that's why the edge didn't polish up that well.

 

[DB_Cruiser]

I am curious about this etching you speak of. I am assuming this would be a mild acid of some sort, which would break down the copper tin a little and help smooth out the surface. But I am quite the noob when it comes to these things. I have only recently discovered some of these other honing mediums and am interested in their care and maintenance.

 

[wade7575]

You use ferric chloride witch is pretty nasty stuff,the stuff most guys use to refresh their stones is used for making prototype PCB boards,you use a solder mask and to protect the part's of the board you don't want the copper dissolved and then you use the ferric chloride to dissolve the copper.

For the Metallic Bond CBN and Diamond stones you use the ferric chloride to dissolve the copper tin matrix to expose more fresh abrasive.

The reason I want to etch the 15K I just got is because it's a bit on the rough side and I'm thinking it's more because of how the stone was finished at the factory and I'm also thinking that may have had something to do with the scratch pattern having so many scratch's in it.

The lens I used on my camera also takes close up's really well and often makes a scratch pattern look worse then it does and it looks not as bad to the naked eye as the picture does but I think it could be better,so I just want to do a quick etch as there are CBN particle protruding threw the copper tin matrix and I don't want to etch to deep to the point that the layer of CBN that is exposed fall's out.

The next finest grit I have is a F4000 grit CBN stone witch feels smoother then this stone so I'm hoping that it's just the copper matrix that's rough.

The Metallic Bond CBN and Venev stones are very low maintenance stones and I have yet to wear back the CBN enough to the point they don't cut fast anymore or don't cut at all,I know one guy on this board told me in a PM a while back that he get's about 400 to 500 sharpening session's out of these before he needs to refresh the Metallic stones.

I am curious about this etching you speak of. I am assuming this would be a mild acid of some sort, which would break down the copper tin a little and help smooth out the surface. But I am quite the noob when it comes to these things. I have only recently discovered some of these other honing mediums and am interested in their care and maintenance.

 

[DB_Cruiser]

That's about what I was thinking, with the exception that the acid is more aggressive than I expected. Thank you for taking the time to explain this!

 

[DeadboxHero]

The acid isn't going to burn your flesh on contact or anything wild.

Just don't be that guy.

Don't dunk your hands in it, Don't drink it, don't wash your eyes with it. Wear gloves and swab on. Rinse off and neutralize with baking soda.

It's pretty straight forward except for that one guy that will find a way to make it a disaster, that guy needs a space suit and a 1 hour safety video just to watch.

That's about what I was thinking, with the exception that the acid is more aggressive than I expected. Thank you for taking the time to explain this!

 

[DB_Cruiser]

Duly noted. To give a little context for my question, I was thinking along the lines of vinegar. I use vinegar as an aid in removing rust from old axes. As a side effect of an extended vinegar bath, the hardened portion of the bit often gets darker. That's what I was thinking in terms of etching. Not etching in the context of making printed circuit boards. But after this was explained by wade7575 , I realized that we're talking about removing a more significant amount of material than I initially thought. Obviously, one would need a stronger acid. And now I have learned not to drink ferric chloride.