Thread: Bio-Diam Diamond Pastes: First Experience

There was a recent post by user Kees on both Straight Razor Place as well as Badger & Blade entitled “TI strop pastes, "user manual"” (links at end of article) which, quite frankly, got me interested in the new line of Bio-Diam sharpening pastes being sold by Thiers-Issard in France.

To be honest, diamond sharpening pastes aren’t new for me. I’ve been using the Amplex brand diamond pastes sold by Classic Shaving for the last few years, and they have served me well. Still, I was wondering what (if any) difference there could be between one type of diamond paste and another, so much so that I popped for the full line of Bio-Diam diamond pastes along with the Chromox finishing paste. And since I’ve gone to all that trouble for myself, I thought I would share my experience with the straight razor community.

I guess the first thing to say is that these pastes are different from what I am used to using. For one thing, the dispenser is totally different. The Amplex stuff comes in a syringe. The Bio-Diam dispenser is a small flask with a squeeze button on the bottom.

The next thing I noticed was the binder. Bio-Diam’s binder is more on the lines of a thin syrup rather than a paste. This binder and diamond combination is supposed to be completely safe, even if accidentally ingested, but I wasn’t about to put that particular claim to the test. Besides, if I get hungry a ham sandwich is a whole lot cheaper.

The different micron-grit sizes of the Bio-Diam are color coded for easy identification. This means that you will have an easier time telling one dispenser flask from another. However, this color more or less disappears once the paste has been applied to the leather. This means that you want to be certain that you label your strops properly before you start to apply the pastes so that you can tell which strop is carrying which micron grit size. If you look at the photo of my strops you will see that with the exception of a very light reddish cast on the 1 micron strop, the rest of the strops appear more or less the same to the eye. So, I’ll say it again, “Label your strops!”

For those of you not familiar with diamond pastes it needs to be said that you will want to have a separate strop devoted to each single grit size of diamond paste. Thus, if you pop for the full set of four diamond pastes (6 micron, 3 micron, 1 micron and 0.25 micron) then you will need a total of four strops. Well, to be more correct, you need four separate leather surfaces. You would have, for example, four hanging strops or else two, double-sided paddle strops or else a single paddle-style strop with four separate sides. And don’t forget yet one more strop for the chromium oxide paste and another totally clean strop for daily touch-up before shaving.

I opted to put together my own strops for this purpose. I sliced some hardwood, notched and sanded it and then glued on some good quality thick, smooth-surfaced, belting leather. This leather is pretty stiff and doesn’t have so much ‘give’ in the surface. I feel that this helps the strop to respect and retain the geometry of the razor edge somewhat more than a softer leather. I have also heard of others who prefer a leather with a bit of ‘tooth’ on it rather than a smooth surface. These handmade strops don’t have any flex or spring, but this is not a problem if you always pay attention and use a deft hand when sharpening. Others may have a different opinion about what type of strop and/or leather to use and I can respect that. But whatever sort of strop you use, make certain that there is a separate strop for each different grade of paste.

Another thing that must be heavily emphasized is that you want to avoid cross-contaminating the surfaces of your strops. The diamond crystals embed themselves into the surface of the leather and you can NEVER get them out. If you get even a tiny bit of a coarser-sized diamond grit onto the surface of one of the strops devoted to a finer grit size you will totally ruin that strop for the finer grit size. So keep things clean. I actually keep my pasted strops in separate, plastic bags to keep the surfaces from touching one another when stored.

Applying the Bio-Diam pastes to the strops is pretty easy, but there are some really important things I figured out along the way.

Because the stuff is slightly fluid, I shook it up a bit to begin with. This probably isn’t necessary, but what IS necessary is to make sure that the paste is at least up to body temperature – you can hold the dispenser in your hand for a minute or two – so that it flows more easily. This will especially make a difference with the heavier grit sizes (3 micron and 6 micron).

Each dispenser holds 10 milliliters of the designated paste and this leaves a lot of extra room in the flask. So before dispensing, lightly shake the contents down towards the top of the dispenser flask. If you don’t do this, you may find yourself (as did I) pushing on the button, but dispensing nothing but air. If you take a look at the second photograph of the inverted container you will understand what I mean.

Go easy when applying the paste to the strop leather. The recommended amount of paste is something like 12 droplets for a start (I split that up into about twenty little half-droplet dabs across the surface of the leather). Now you want to massage the paste into the leather with a fingertip. At first it will feel a little slick, but in very short order it will dry to little more than a very slight gloss on the leather surface.

If you work too slowly, the droplets might even dry in place, but you can easily add a droplet of water which will rehydrate the binder, allowing it to flow once again. I had to do this once or twice when I let too much of the paste dry in one area of my strop.

Here’s another hint. Don’t bother washing off the paste from your finger during the application process. Just start off by applying the very finest 0.25-micron grit to its strop first, then do the application of the 1-micron grit, then the 3-micron saving the 6-micron for last. In this way, although the finger is carrying some grit over from one strop to the other, it is always a finer-sized grit to a coarser grit strop which is perfectly acceptable. By doing it this way you will save a bit of the precious diamond crystals. Once all of this is finished you can wash up properly.

Then it was time for the last strop and its application of Chromox finishing paste.

Chromox comes in a small jar and is an extremely finely-ground chromium oxide paste in an oil-like binder. Once down on the leather, that oil just seems to disappear. Now the instructions are that one should apply Chromox to the leather and then use a clean rag or disposable tissue to wipe off the leather surface until no more Chromox is seen to come away on the rag. This is so that no chromium oxide remains on the leather surface, but only down in the pores of the leather.

“So, OK”, I thought, “I’ll just put on a good coating to begin with.”

I applied a thin, even layer of Chromox all the way across the leather surface, presenting a uniform green coat. Big mistake! I must have used at least ten disposable tissues – wiping, wiping, wiping – before the surface of the leather was clean enough to use. Once properly treated with Chromox, this strop, too, didn’t look so very different from untreated leather.

It should be noted that if you do not clean off the leather properly, the excess Chromox will end up on your razors. So, my best advice is to use only a little of this stuff – two or three dabs, maybe – and then rub it all around with your fingertip and then clean off the leather. Do not apply too much unless you like having lots of green Kleenex in the waste bin.

So, then it was time to test. I grabbed five or six of my favorite razors and went to work.

I don’t have any fixed notion of numbers of passes on which surface for which razor. Instead I rely upon my trusty eye loupes (7x and 15x) to magnify the razor’s edge. This lets me see not only the initial condition of the edge, but also allows me to follow the development of the scratch pattern and/or polish as my honing or stropping work progresses. I strop in a slow and careful X pattern, stopping every once in a while to take a careful look at the razor’s edge (both sides) under the loupe. If I see an even scratch pattern, end-to-end, on the razors edge, then all well and good and I’m on to the next finer grit. If I don’t like what I see I return for more passes on the current strop. I repeat this process for each grit all the way down the line. This is perhaps a little fussy, but it works for me.

I didn’t notice any real difference in the stropping action of the razors on these pasted strops compared to the stropping action on regular unpasted strops; there was neither extra resistance nor extra slipping. Nevertheless, the razors were finished very quickly. And I must say that the sharpening results were really, really fine. After finishing off a few of the razors I dashed upstairs to give myself a test shave. I was not disappointed. Smoo-o-o-th!!

[ Note: I had an appointment for a haircut the following day. I took along the entire set of pasted strops and sharpened all eight of my barber’s razors. They all came out brilliantly sharp. That was one, happy barber! ]

But, OK, I can spout out all sorts of superlatives about just how sharp the razors were and just exactly which hairs I was able to shave off the rear end of which small insect (without lather, mind you), but the real question is what advantage these pastes offer.

These are my impressions:

The grit sizes for the Bio-Diam diamond pastes (6-, 3-, 1- & 0.25 micron) differ from those of the Amplex pastes (9-, 1, 0.5- and 0.25 micron), but that doesn’t seem to make any difference in terms of the ultimate sharpness of the razor’s edge. But the following things do make a difference.

The Bio-Diam pastes cut faster than what I had been using. I don’t know why this should be, but I definitely wasn’t working as hard or as long to bring a good edge to my razors. I will have to attribute this to both the quality and the quantity of the diamond crystals in the paste.

Second, not only do they cut faster, but there seems to be more control while I am stropping on these pastes. But of course there is no real paste layer on the surface of the leather here, but only that thin binder and diamond crystals worked down into the surface of the leather. It translates into what I experience as a better contact and control of the razor on the leather. I’m going to attribute this quality to that special, thin binder.

The third thing I noticed is that the strops treated with the Bio-Diam paste don’t seem to load up and glaze over in use. Of course, after doing about ten razors I could see some darkening due to deposited steel, but a simple swipe with a paper tissue was sufficient to remove this. Again, I think this is due to the binder.

Regarding the Chromox, I can say that it definitely did what chromium oxide is supposed to do, that it softened, smoothed and refined the edge of my razor following the diamond stropping. Better or worse than any other chromium oxide paste is something I could not say.

I will have to admit that all the above performance comes at a bit of premium since the Bio-Diam diamond pastes are more expensive than the competition when considered purely on a volume for price relationship. But you get what you pay for and I feel that there is a definite quality difference in these pastes. The quality and quantity of diamond crystals in a sharpening paste is of paramount importance and my impression is that the amount of diamond crystal within these pastes is not only greater but also of better quality. Likewise, the carrier paste is just as important as the crystals and here again there is a definite quality ‘plus’ in this formula. This binder goes down easily, holds the diamonds to the strop, doesn’t load up and allows for easy cleaning of the strop surface. So when I consider the better performance and the good results, then the higher price seems a small investment, especially when compared to the value of one’s valuable razor collection.

But, OK, this is not the only diamond crystal sharpening system available, and for each kind of diamond sharpening material – paste, fluid, spray, Mylar film, stone, etc. – you will find enthusiastic supporters as well as severe critics. But the bottom line for me is that this paste sharpening system really does perform. It works as advertised and seems to be even better than what I’ve been using. It gives me a brilliant edge in less time with less effort. I’m not going back.


The following are the links to the posting by user Kees on both SRP and Badger & Blade.

http://straightrazorpalace.com/strop...er-manual.html

TI strop pastes, "user manual" - Badger & Blade

Nice paddle setup!

Thanks for the write-up!

I agree absolutely - I was a bit dubious re this system but TI persuaded me to have a go and stock it -I'm glad I did. The ease of maintaining an edge is quite a marked improvement over some others i have tried. It may be a bit on the dear side but then the really good stuff usually is!

Thanx for sharing Ignatz. Just one question: on which side of the leather did you apply the Bio-Diam?

Thanx for sharing.
......and what type leather and what width?

To Kees & Matt321;

This is the leather I used for my strops. It is intended for belts. The finish is smooth on the front side, but dry without any sort of laquer or oil. The dimensions are about 39.5mm wide ( 1- 9/16 inch) and 5mm thick (3/16 inch). It is really intended as basic work material for a leather worker who would proceed to cut, punch, emboss and tool and then finish as desired. I'm really sorry that I cannot be more explicit. I purchased some meters of this from a local store which makes custom leather goods about seven years ago (?) and do not properly recollect the particulars. In fact, I cannot say in all honesty if it is cow leather or horse leather.

The photograph shows both the front and the back side of the leather. The back side has a 'tooth', but is really more or less unfinished and does not have the same degree of roughness all along the length of the leather which is why I chose to use the smooth, front side for my strops.

I also remembered that I did not include a shot of the underside of the Bio-Diam applicator. So I put two of the flasks into the picture, with one lying on its side to show that little push-button underneath.

- Ignatz

I'm serously consdering the full range. it recomends after finishing honong of apropiate hone to go from 6m all the way throught to cro .ox i would of thought that may be too much starting out at 6m and may not be nesacery as most of us can finish on just .5 dp or d spray or cro.ox. so i'm not sure what do

I just got full range of bio, TI recomend starting at 6m then 3m , 1m ,0'25 followed by cr.ox, I have to experiment with paste, surley after a correct honing 6m would be unesacerry. Also on a razor just out of box they recomend this. Seems a little agressive starting point. I have tryed to day on 3 razors and although very sharp the edge seemed a little agressive on two of the razors one was not as agressive.Any one else using these paste who could comment.

Maybe the intent for recommending the 6m for newly honed blades is to insure that the blade edge is "seated" or "profiled" for the strop interface. The hone is flat and rigid, while the strop is slightly flexible. The finer pastes can't remove enough steel for the edge to conform, so the 6m is used first. This is only done once after each honing.

I bought a 6-foot by 1.5 inch strap of leather from Tandy for about $15. Now I need to find something to make the paddles out of. The store I visited had latigo straps of the same size for about $25. The ones I looked at were very uneven on the surface so there would have been about a 40% cull from each piece.

I just honed two da's one coticule only and the other da coticule followed by 6m 3m 1m 0.25 cr ox. They both shaved well, the pasted edge was still more agressive. I have tryed on 6 razors now all of them have turned out more agressive. I would say it good for some who carn't get sharp enough from the hone, but i can, so may be i'm over honing the edge with paste. the last da i did i only did 5 laps on each grit, it was the best result yet, this stuff does cut fairly quik