Today I have made the last piece of the puzzle – a small whetstone for edge maintenance in the field. I expected it to take me two to three hours, it took me twice as much. Partly because it was the first time I was doing it so I did not really have a clear plan on how to properly proceed and what will work best, partly because I screwed up and I had to start all over with one part. But I think that if I were to make another, it would indeed be those two hours that I used for price calculation.
I started with a piece of native, strongly metamorphized phyllite. It has visible big garnet grains and it is very hard.
I cut a strip off with a diamond stone cutting wheel in my angle grinder. I have used that wheel also to roughly shape it and thin it.
For the second, fine layer, I have used a piece of old roofing shale. Those can sometimes be found around here on building sites and even in my garden.
Those are not native stones, they are the remnants of long demolished houses from before WW2. Initially, I wanted to use a different piece of local phyllite, less metamorphized, softer, and with finer grain, but I screwed up and it delaminated down the middle, becoming too thin. So I went for the shale for my second try because it is stronger and I wanted to be definitively done today.
Using five-minute epoxy, I glued both roughly shaped flat stones on a thin jatoba board, making a small stone popsicle.
After the epoxy cured, I shaped the outline, covered both outward faces with adhesive tape, and submerged it whole into linseed oil for a minute or so to soak the wood.
After that, I had to grind down the faces a bit again, it was just a bit too thick to fit into the pocket. I ground them down with the diamond wheel and then flatterooned them on granite stone with wet&dry carborundum abrasive paper on it.
Both phyllite and shale are soft enough so they can be shaped with abrasive cloth or paper, but hard enough themselves to abrade steel.
This is not a stone for serious sharpening work and I have told the customer so. Its abrasive action will be relatively mild compared to modern carborundum-based whetstones, even on the rougher phyllite side. But it should be excellent at maintaining an already sharpened blade and giving it an occasional touch-up during work. I have used pieces of phyllite or shale for exactly that, although those were stones found by the wayside, impromptu flattened and used out of necessity, not nicely crafted like this one.
Thus almost all work is finished – tomorrow I will sharpen the blade and make nice pictures to present here and on Instagram.