Diamond Paste

Working with Poly and Mono Diamond 

Diamond pastes, sprays and slurries come in a variety of packages, types, etc. For razors – we often see pump bottles with a small amount of industrial diamonds in a water-based medium.

After trying many different brands, mediums, grits, etc – I can say that they all seem to work nearly identically; the caveat is that how you use one or another might be a little different.

Using pastes – as you see above – for example; that mix is fairly thick and I like to put it on a leather substrate and strop on it. Some like to use hanging linen strops or balsa strops. All of those styles and techniques work – but each one requires a bit of a change on one’s approach. Pressure, lap count, density of abrasive on the substrate, etc – all of this and more have to be judged, calculated and executed for each unique scenario.

It’s not all that scary – all we have to do is put a little bit of the abrasive on a medium and try it out – add a little more here/there and adjust pressure as we go. Eventually, after experiments and paying attention to results, figuring out how to use it proficiently becomes a fairly easy practice.

In the photo above – I’m testing a brand of pastes that I’ve not tried before. The reddish smear is 3.5µm paste on short piece of horse hide. I just happened to have some horse hide lying around because I was making myself a new strop. I save bits of leather for this type of experimentation – if you don’t have any leather on-hand, cutting up an old belt or a quick trip to a craft shop can fix that. Or – just use another method. That knife is what I use to cut down the hides into strop-like shapes and lengths, and it is in need of some fine-tuning. 

As it turned out – and, as expected, the 3.5µm paste was a bit fine for what I needed to do. I’ll be going to a 10µm paste to help correct the edge further. However, the treatment from this test did enhance that edge enough so I was able to produce a nice smooth even cut  on a piece of hide.

Diamond paste is very effective and a little goes a long way.


Straight razor edges and smoothness.

This is a volatile subject and I think everyone has to come to their own understanding here. So – I’ll keep this part short; and please note that what I’m about to write reflects my own interpretation based on my own tests. Someone else may find that their results, from seemingly similar tests, to be quite different. 

To me – using .25µm diamond spray or paste as a final finishing treatment on a straight razor – it’s a fast ticket to a ridiculously sharp edge; it works like a charm. The liability that I see in this approach to finishing an edge is that the ‘window of opportunity’ is very narrow and a lot of very critical testing was the only way I could find that ‘sweet spot’. What I found was that diamond paste brought the edge along quickly but that first level of ‘sharp’ from the diamonds was too harsh. With extensive testing – I found that approximately 200 laps on a suede leather paddle strop got me ‘that’ edge. 

Sharp? Hellishly so.

Smooth? Ridiculously so.

Tedious? Off the charts – this was a ‘blink and bleed’ edge. 

In an attempt to ‘quiet down’ the .25µm edge, I employed a .1µm diamond spray afterwards and that seemed to add a bit more ‘smooth’ and reduce the ‘tedious’ factor. All in all, while this series of experiments were very successful – I decided that using this stuff for final finishing produces an edge I don’t like, and the whole process was a royal pita. 

I did learn a lot from fiddling with the myriad of diamond sprays, pastes and slurries, and as you can see, I still work with them. Plus – I still rely on those mental-bookmarked edges as a comparison when honing on natural whetstones.

When I hone an edge - I’m not looking to achieve the same levels of sharpness that the diamond pastes provided, not exactly anyway. But – since I do strive for max sharpness/smoothness, my experiences with those diamond products brought an interesting perspective into my personal honing styles, practices and techniques.  

© Keith V Johnson 2014 - 2018