Sharpening for chisels and planes

[Jessica de Boer]

I have this one very strange chisel made by Nooitgedagt, they were a large Dutch tool maker. The blade is plain, Swedish high carbon steel and I tried to sharpen it once on my Atoma 1200 plate. The weird thing is that it literally tore diamonds from the surface of the plate when I sharpened the bevel. It's the only chisel I have to wants to do this but it's a complete mystery why this happens with this chisel. Maybe someone has an idea what's going on with this chisel?

[Kees Heiden]

I won't quote your entire post Vince, it was a bit long I get the imprssion you were debating that the dip at the end of the stroke to make a convexity is wasted effort

What I was trying to say, is that the dip at the end of the stroke is just removing metal that has to be removed at some point in the future anyway. You are just doing it a couple of months earlier. So it is not wasted effort.

But I sharpen differently, I hollow grind and use a small microbevel. Or better, I just aime the chisel at the stone and somehow it turns out sharp.

[Jason Martin Winnipeg]

Sharpening is a very curious beast. I've never seen any two people sharpen the same way, and it seems to be as personal as a signature. I learned how to sharpen from Paul Sellers, but I still don't do it exactly like he does.

It's also curious in that you can go very very deep into the methodology and science of sharpening a piece of metal if you so choose, but it's also not necessary to do so to get good results. Personally, I don't find sharpening to be that interesting, but I do find how people sharpen to be very interesting and I'll watch sharpening videos just because I want to see how another person does it, not because I need to refine my technique or method.

[Luke Dupont]

The bevels are a tiny bit convex. I'm not sure making them dead flat will offer an additional significant improvement.

I think you're right; as I said in my original comment, I think I actually prefer a tiny bit of convexity. I also found that it helps to round the very top of the bevel off, as it can catch and jar the chisel if you are too shallow.

My father has been using Atoma plates since forever for his Ichihiros and they usually last him 4-5 years. Given that a replacement sheet is just 35-40 Euros I'd say that's very economical. And they actually get faster as the diamonds level out, especially the 400 and 600 grit plates.

Ah, nice. I think I should try a different brand of Diamond Stone. I think I bought DMTs and found them to wear out quickly, but I've bought a few different stones here in Japan that seem to hold up better. Needing a nice flattening plate, I finally bought a quality, coarse diamond stone (150 / 600 grit). It has so far performed exceedingly well for flattening the backs of chisels. We'll see if it holds up!

It could be, as you stated in the post below, just the particular steel of the last set of chisels that I had. Was that strange Nooitgedagt chisel super hard, or does it seem comperable to other steels you use?

[Jessica de Boer]

Was that strange Nooitgedagt chisel super hard, or does it seem comperable to other steels you use?

It's about the same hardness as a couple of Stanley Sweetheart chisels that I have. All of my Japanese chisels and the Stanleys sharpen beautifully on my diamond plates. The Nooitgedagt is definitely made of a very strange steel.

[Jessica de Boer]

I was sharpening my oire nomis today and I actually managed to get the bevel on 3 of them flat enough that they stuck to my finishing stone. I was able to let go of them without them falling down.

[Stewie Simpson]

https://www.toolsfromjapan.com/wordpress/?p=564

the Sigma Power # 120 grit stone.

Note the sharp corner edges of the stone have been removed to allow a more consistent abrasive pattern when working the backs of chisels and plane irons

The inherent problem of metal glazing with this stone was addressed by using loose sic powder as a cutting slurry.

Top surface flattening of this stone is best done on a flat bed of loose sic slurry.