0.5 micron Jende Polydiamond Emulsion scratches 3 micron mirror finished blade?

[NicoColt1911]

Hello,

I have a problem, maybe you can help me figure it out:

I recently bought a KME sharpener with the diamond stones and 9, 6 and 3 micron lapping films. I got really good results. Mirror edges without any visible scratches. It looked perfect to the naked eye.

Then I had this idea to try to go one more step and bought 1 and 0.5 micron Jende Poly Diamond Emulsion.
Now the problem is that I am from Germany and some items aren't that easily available here. So right now I am still waiting for my KME strops and couldn't test them with the KME. But I ordered the 0.5 micron diamond emulsion with a full size Jende Nano Cloth Ultra strop because I thought that way I could use the diamond emulsion on my free hand sharpened knives as well.

Long story short: I loaded the Jende strop with the 0.5 Jende diamond emulsion and allowed it to dry over night like shown in the video. Then I used it on one of the knives that had a 3 micron lapping film mirror finish before. I know that gap is quite big but I just wanted to give it a try to see how the nano cloth strop feels. I didn't expect any visible result. But sadly I was wrong: Good visible deep scratches on the whole edge. I am not talking about some small light scratches. No. There are plenty scratches so that the mirror finish isn't mirroring anymore. Even worse you can feel now that the surface is uneven/ coarse. I am 100% sure that I could have a better finish with the 1500 grit stone alone.

I won't say an user error is absolutely impossible but it is unlikely. Maybe I didn't shake the bottle enough, maybe I added too little emulsion to the strap and maybe I applied too much force. But I have some experience with normal stropping paste on leather strops and something like that never happened before.

And how can you even scratch a 3 micron blade with a 0.5 micron diamond emulsion to begin with? Maybe that is an error in reasoning but when a 3 micron (8.000 grit) finished surface is treated with a 0.5 micron (30.000 grit) strop I wouldn't expect it to be ruined.

Could it be that the emulsion I got is somehow faulty and has a lower grit than stated?

 

[Diemaker]

My take is contamination. .5 micron diamond will not do much even looking under a microscope and too much will not make bigger scratches.

 

[ToddS]

My guess is that the deeper scratches were there already, but obscured by the finer scratches. You polished away the fine scratches, making the deep scratches easily visible.

Nanocloth and that type of resilient polishing fabric is specifically manufactured for use with sub-micron grit. It is too soft for larger grit particles to receive enough force to scratch the metal.

 

[NORTHWEST_KNIFE_GUY]

I agree with Diamaker, all it takes is one little spec to contaminate it and add scratches to your perfect mirror. I would go over it again with the film (coarsest needed) to remove the scratches and try again only try to clean the strop really well to make sure there are no contaminates. When you add the diamond does it look nice and even or lumpy and not mixed well, wondering if there is agglomeration taking place in the emulsion.

 

[REK Knives]

This is actually a pretty common problem with very fine (below 1.5 micron) fine diamond emulsions in my experience anyway. I've actually tried 8-10 different ones with most of them having this issue. Of course, It could be contamination or revealing of deeper scratches but in my case I ruled that out.

 

[Wowbagger]

I'm not all that up on Jende. Maybe they make great stuff but the one stone I have that came with their name on it, a Jende 120 supposedly "Shapton Glass" stone for my Edge Pro Apex, sucks big time. The stone is way too soft and just keeps getting softer and softer the more I use it in one session. ALL of my other Shapton Glass Edge Pro stones that do not say Jende on them are much, much harder and do a first class job on my knives; I'm very pleased with those stones.

I can't speak to Jende diamond abrasives.

 

[Wowbagger]

This is actually a pretty common problem with very fine (below 1.5 micron) fine diamond emulsions

are they clumping (fine grit sticking together to make little dirt clods) ?

My diamond emulsions are very old and nearly impossible to dig out of the syringes so I don't trust them to spread out as they should.

 

[REK Knives]

are they clumping (fine grit sticking together to make little dirt clods) ?

My diamond emulsions are very old and nearly impossible to dig out of the syringes so I don't trust them to spread out as they should.

Some that I have tried have done this, but most have not. And the stuff that did was fresh from the mfg so it was ridiculous, don't know how they stay in business lol

 

[Wowbagger]

And the stuff that did was fresh from the mfg so it was ridiculous, don't know how they stay in business lol

Yet one more argument for just going with high quality water stones for "stropping"; 15,000 20,000 30,000 Shaptons etc.

He said with his typical banshee cry of "loose the strops".