essexalan":1cy0tvi1 said:
A good Washita will last you a lifetime or two which would not make it economically viable for Norton who would much rather cover that market with their waterstones and made in Mexico India oilstones. Perfectly happy with the Sigma 120 so no need to change, I reckon it hogs off steel faster than a diamond plate and you can easily flatten it if required.
I did prep 5 old steel English firmer chisels yesterday morn going from a bit of a mess to a good cutting edge in about an hour using belt and waterstones Sigma 400 and 1200 for the back and 6K and 13K for the bezel. Just a quick rub over with an Atoma to clean the swarf off, the stones did not need flattening. Suits me enough that I will stick to it. Yes you can get a hair cutting edge from a Washita but I can get the same from a 1K waterstone on a Japanese kitchen knife, similar scratch pattern but a bit toothy for my liking.
Certainly not advocating replacing the 120 if it works fine. Just making the point that the type does work a little better and with no maintenance if it's oil as its designed. The cut is about as fast, too. The only place where people go wrong with them is buying big vintage silicon carbide stones that have gotten hard - they are almost impossible to use due to an inability to release particles.
re: the 1200 and 13000 sigma powers - I have those stones. The edge off of a washita is much better than the 1200, but of course, not as fine as the 13k. I know a lot of people slurry a washita, which I do for one that I use to set the bevels on razors from time to time (I don't ever reset a bevel unless I get a new razor and it needs it), but I don't think it's great policy if using the washita to finish an edge, and it's a transient effect, anyway, given how soft novaculite is compared to other abrasives.
I have gone to finishing new edges now with sandpaper to washita and then that's pretty much it. (I just noticed that I did lap the washita here, relatively lightly, because I wanted it to work the groovers of the sandpaper off).
https://youtu.be/OOMjSwcEnsU?t=10m
(pardon the whine, it was due to a temporary software problem from an android update)
I probably won't finish irons any other way going forward. there are certain things that the limited abrasive power of the washita does really well. One of those is to remove imperfections but not do that much to what's left once a surface is flat. I have only gotten one comment on the flatness after this process, but it was from Brian Holcombe, who remarked that the iron was flat to his stone without any work. Used in combination with filing, I can get plane bottoms to less than 1.5 thousandths flat with this lap, too - it stays flat.
I went to the method above because once I started to build planes, I still need the back of the iron to be as flat as it would be if it were factory made (it needs to take a polish at the edge on any flat stone without additional work), but also be able to remove pitting on parallel and taper plane iron sets that I find relatively quickly. I've pretty much abandoned water stones for this kind of work. Or I should say, I've pretty much abandoned waterstones - except for japanese finishers. I still like them quite a bit, and the level of sharpness in this video, which is plenty fine for any work, is about doubled by a middle of the road suita stone (and those are expensive, but they come without the fragility that synthetic stones have, and a little more of the flexibility to determine fineness by pressure/slurry, etc.