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Slurry dilemmas


Well-Known Member
Welcome again,

I was thinking recently - after another unsuccessful attempt at Unicot edge - that crucial factor, apart from the X-stroke, is slurry thickness. Remembering all the advice about keeping the slurry not too thick (dulling effect) I saw Bart's video and realised that I used far thinner slurry than he shows.

Before, I was trying to reach arm shaving stage on something more or less like this:


After watching Bart's video I started using something more like this:


Which, after several half X-strokes, turned into this:


Could you please estimate whether this thickness is appropriate? I'm well aware that it varies from coticule to coticule, but I'd love to get some hints. I reached the shaving arm sharpness, but failed to develop Unicot edge (for final slurry stage with tape I tried something half way between 1[sup]st[/sup] and 2[sup]nd[/sup] photos, and then water of course).

Thanks in advance, regards,
that looks pretty good to me. The key to getting that final edge is gradual dilution of the slurry, IME. Keep diluting that slurry and working at it, it'll get there:)
Hi Matt. I looked at that pic and instantly thought dayam the slurry in the second and 3rd pic looks dense. Then I remembered what paul said - keep diluting. Allthough the third picture seems so thick it should be only for major bevel work - remember the slurry dulls the edge too.

Best thing I can recommend from experience is just go for it Dilucot. Dilute slowly, but DONT let the slurry thicken up like it did from pic 2 to 3 there. Ive noticed what Gary has been saying about the feedback - once you get close to maximum keenness from the slurry your working on, it seems like the stone tries to grab the blade at the end of the stroke - some extra resistance. At this point, add a drop or so, and go again untill you can feel the change. Keep this going up untill your on water.

At the end of the whole process, if your not at the keenness you want, add a layer of tape, swipe your slurry twice, maybe 3 times across the coticule - you dont want an obvious slurry like in your 1st pic, infact, i think you need it so you almost cant tell theres a slurry. Give it 20 laps, then move on to water. Remember, at this final slurry stage on unicot, you dont want to make the secondary bevel too large, so the very light slurry and few laps are crucial - dont overdo it. I had that problem many times, and little IS more!

Hope this helps :thumbup:

All great advice, imo.:thumbup:

Slurry #2 is good for bevel work. Half strokes and such.

Slurry #3 is too dense. You should not allow your slurry to become as dense as this. In fact, you should not allow your slurry to become any significantly denser than #2. While honing, I'm almost constantly adding drops of water. I.e. during the "halfstrokes" part, I'm adding water to the slurry each time I flip the razor. During regular X-strokes, I add a drop every 20/30 laps or so. While diluting, I add several drops every 10/15 laps, or every 20/30 laps near the end. These are all estimates, because I nearly always go by observation. Slurry consistency may seem difficult in the beginning, but a time will come that it becomes second nature. I hardly ever think about slurry density.

Add a few drops of water to slurry #1, and it's ready to cut the the secondary bevel of a Unicot edge.

Best regards,
Thank you all, gentlemen, great advice! :thumbup: :thumbup: :thumbup:

I did some honing yesterday, keeping in mind things you wrote, but I didn't manage to try the results - gonna go for it today!

kind regards,
I'd like to take advantage of this thread -matis, I hope you don't mind- to ask about my slurry dilemma.
With time i've learned how to keep my slurry for drying too much; my problem now is that slurry drips from the stone. So I am left with less slurry on the same surface, and what's left dries easily.
Only once or twice in the last dozen honing sessions I managed to avoid the slurry draining out of the stone.
Since my stone is fairly big, should i consider the slurry that gradually leaks out of the surface of the stone to be "excess slurry" and keep using what remains? Or is there a way to avoid this?
Maybe this is a symptom of a wrong honing stroke? For instance, when during the stroke you get to one end of the stone... inevitably the blade pushes some slurry down!:mad:
I find that by stopping half inch short of the ends slurry loss can be reduced, also by tipping the stone slightly away from the razor, i.e. if your right handed tilt the stone slightly to the left, this helps stop the razor dragging the slurry off the side when doing X stroke, and lastly if your doing a dilocut hone you can get a lot of the slurry staying on the blade itself, with practice this is a good indication that its time to dilute, that is the razors edge cuts through the slurry and lifts it on top of the blade, what I do is keep the razor in my dominant (right) hand, and lift the hone off my left, so I now have both razor and hone in my right yeah? then use 2 fingers of my left hand to pick up a little water and drop it on the stone, pass the stone back to my left, a couple of straight slow strokes to mix it in and back to X strokes, with practice its saves losing a lot of slurry, also I rotate the stone 180 degrees so that the dry slurry gets incorporated every dilution, and it helps to wear the stone evenly over (a lot of) time.
Hope that helps and makes sense?
I could post some pics??
Dr Ralfson.
First of all, allow me to reassure you. This is once more one of these things you worry about in the beginning. I did too. Later on these problems solve themselves and you'll wonder when and how that happened...

Of course, that answer is just no use for you right now, so I'll do my best to give some practical advice, in addition to the good Dr. Ralfson's excellent post.

The first practical advice is to stop worrying about slurry too much.:D
99.9% of the slurry is doing nothing. It's just being pushed around. The only garnets at work are the ones in a very thin layer underneath your edge. Hence you can afford to loose some...

The good doctor is right to stop the stroke before the slurry is pushed over the rim.
Another tactic, is to think of the spine as a sort of squeegee to catch the slurry and drag it along to the other side.
If you watch this video real close you'll see what I mean.

That's about all I can add.

Kind regards,
Whoa.. nice video, Sir Bart:w00t:

So, what was that paste at the end? CO2 paste?
tat2Ralfy said:
also I rotate the stone 180 degrees so that the dry slurry gets incorporated every dilution
Slightly tilting the stone to the left... stopping before reaching the end... regularly rotating the stone... this all sounds really useful. I'm going to try right away.
Bart said:
99.9% of the slurry is doing nothing
Yes, I should stop worrying too much. As every novice coticule user maybe I just need to be reassured :-/
Anyways you're right, I always have a pool of slurry on the stone that just stays there doing nothing, while only the little "wave" underneath the edge is really working on it.
I am sorry that i revive this old thread, but I didn't know where to put this, it's pretty unimportant, after all, but interesting.

Yesterday I was setting a bevel on this old Sheffield wedge.
The slurry was gradually turning darker. It had developed a nice lead grey colour, when suddenly (yes, suddenly: in a 15 secs time after 5 minutes of honing) it turned olive-green:

I had observed particles of metal on a coarse waterstone gradually turning orange from oxydization; but never a coticule slurry, and never so abruptly.
That's an interesting observation. Normally my slurry turns from light gray to dark gray, sometimes to black. The only times I've witnessed a color hue entering the mixture was when using my blue tape.

Thanks for sharing.

Kind regards,
Mine turns red like that too, if I put it down to light a smoke and come back. I never change it though, I don't think it hurts anything.