Thread: Reasons I feel hones have to be sedimentary

Originally Posted by yuzuha

I read an artcle on superpolishing automotive shafts once.... Basically what they do is have the shaft on a lathe and a motorized grinding wheel on the tool post (all computer controlled of course) and the key to it is the pressure and viscosity of the lubricant. It forms a fluid bearing between the shaft and grinding wheel and only allows contact between the tips of the grit particles of the wheel and the remaining peaks on the shaft.

Hi Pam, I was hoping you might have that yasuri makers vid in your collection of knowledge.

No, but there is a pic of a yasuri style file on this page
Sauer & Steiner: One file to rule them all - and in the Ebony dust bind them. and Woodcraft has some "feather edge" yasuri saw files.

The coticules are metamorphic and metamorphosed through heat and pressure from sedimentary stone. The heat and pressure caused the garnets to form. They're harder than steel but the underlying phyllite (mudstone) is soft and wears readily. Garnet cleave readily and that's different from other crystals and they present fresh sharp new surfaces to the steel. Garnet sandpaper is used by many woodworkers for just that property.

There are other hones such as slate which is metamorphic after the sedimentary shale. It's harder than shale but I don't find it to be a robust honer.

I have two jasper hones. They were made into necklaces on leather things, Viking style. The Vikings didn't use jasper though and neither do I as it's too slick. I do have a 3 lb. hunk of jasper on my bench and I've been thinking about what to do with it. Haven't played with it too much so don't know about honing razors with it.

Howard, if you feel up to it, would you mind trying to "lap" the jasper to different "grits" and let us know how it goes? I feel it is too slick because you probably lapped it very smooth, but I'd be interested to see if texturing it would make it cut rougher?

I would put money on it acting pretty much like a file as in Pam's post up top. So finer grooves finer finish?

That's what I've been saying for the longest time and for teh longest time I was shot down so...

I am going to put it this way, the file or rasp made out of something harder than the steel your using at will definitely work. The smooth stone probably also works, jewelers and watch makers use them to polish stuff so I guess they do work somehow.