I am struggling with my La Lune stone, and more precisely, with correctly using the nagura stone. Unless I am mistaken (and I might very well be), I am trying to do a tomo nagura.
I have the La Lune base stone, and a La Lune slurry stone, which should be the same. These are natural slate stones, and it might be that they do not come from the same vein, and one of them could be harder than the other. However, the color of the two stones is very similar – and there is much less variation between them than between the stones I see on the pictures on the website. By default, I would assume that they are identical in hardness.
The issue I have is the following: I cannot manage to create a slurry with the slurry stone without scratching the bigger stone. The slurry stone has been chamfered and I see no sharp edges, so I guess that this is user error on my side.
One known unknown: I have no clear idea on how much pressure I should use. If I use very little pressure and put the slurry stone on on of its flat sides, I seem to get an aquaplanning effect where the slurry stone seems to glide on the underlying stone without producing any slurry (I have tried this for a couple of minutes, so I don’t think the issue is impatience on my side). If I increase pressure or put it on one of its edges, I do produce slurry, but I get scratches on the underlying stone (there are also some visible scratch marks on the slurry stone).
I tried to use dish soap to break the water’s surface tension, without much success. I also thought that, maybe, prolonged exposure to water might make the stone softer, so I tried to soak the slurry stone longer (I tried leaving it 30 minutes in water before using it), but this does not seem to have had any noticeable effect.
Sure, I can use a diamond stone directly on the base stone and produce slurry in this way, but it’s a shame to have a slurry stone without being able to use it.
So, what am I doing wrong?
Pinging @gcgallant@sub.wetshaving.social
gcgallant@sub.wetshaving.social 1 week ago
Often, slurry stones of all types are maddeningly slow. What I do with all slurry stones is to round one or more edges using a flattening plate or SiC sandpaper. I also rough up any surface that is adjacent to a rounded edge. I generally throw the slurry stone(s) in a small dish of water while I get other parts of my sharpening kit together. The idea is to get the binder in the stone a little softer. Five minutes is all you need.
To raise a slurry, I use a rounded edge and rub it on the base stone with light to medium pressure. Using the flat of a slurry stone distributes your downward force over too large an area and impedes the breaking off of stone bits. A rounded edge does not typically scratch the underlying stone. With some stones, it will take a while to get a slurry started, but the thickness of the slurry will build quickly once a start is made.
In the case of a tomo, I often use a diamond plate to raise a slurry simply because I’m impatient. I scrub lightly with the plate. I’ve been told at length how wrong I am to do this. There is the risk of diamonds getting embedded in the base stone’s surface, or of diamonds getting in the slurry, or that the surface texture of the base stone becomes too coarse to properly finish an edge. Yet, I manage to get great edges. I’m convinced (atm) that these concerns are all low probability.
Recently, I came across the method of using a diamond plate to raise a slurry, and then use a slurry stone (along with the slurry that was raised) to modify the surface texture left by the diamond stone. I’ve used this method and it seems to work well.
Hope this helps.
PorkButtsNTaters666@sub.wetshaving.social 6 days ago
Thanks! This looks very helpful - I’ll check whether it works!
gcgallant@sub.wetshaving.social 6 days ago
Let me know the outcome.