Thread: Slurry Dulling

Originally Posted by Frankenstein

As far as I know, it was a term used (first?) and frequently on coti.be, specifically for coticules. There is nothing more fun than covering a coti with a mud slurry and proceeding to do countless laps. Unfortunately it doesn't really sharpen your razor. The simple, but non technical explanation over there, was that the rate of steel removal was higher than the rate of polishing therefore the edge of the bevel is never allowed to reach its minimum effective width.

I know that you guys are all being humble and what not, and know much more about it than me, but the fact that one needs to dilute slurry on certain stones validates the idea that dulling exists, and whether you agree with it or not, if you do dilute by default you agree.

Good discussion here.

I think there is something about this above statement. Assuming that the slurry don't change its properties while honing, and that slurry consistency is the only variable I think this is quite a good description. For a given slurry there is a finite sharpness to be achieved (which will/could be different for different honers, stones and steels). If the razor is duller than this sharpness, it will be refined until it won't get sharper on this slurry consistency. If it is sharp to begin with, slurry dulling will take it down to the sharpness dictated by that very slurry. For me, this is apply to honing on a coti.

If, however, the slurry changes as it gets worked (breakdown, slurry particle rounding, whatever) the slurry may allow for more edge refinement and a sharper edge by working it longer. Without entering the existence or non-existence of the breakdown, this is what I experience on some jnat slurries. The honing feedback often gets smoother and the bevel polish/haze becomes finer and finer while keeping the consistency constant (not diluting). Still, there is a balance act between consistency and slurry refinement, and at any point in time the slurry consistency is either too thick vs fineness (dulling effect), just right (edge gets sharper) or too thin (edge gets sharper, but at a slower rate).

Going through a nagura progression, to me it seems like for each new step, the edge is taken back a tad, and then gets refined to a sharper state than on the previous slurry.

Of course, this leaves the question open about what really happens at the edge and on/under the bevel while honing. On the other hand, as long as the blade feels good on the stone, the shaves are nice and I'm having a good time honing it doesn't really matter

keep the slurry talk coming!

Sedell