My first hollow grind

[Federico Mena Quintero]

I have a smoothing plane whose iron, through repeated sharpening, had acquired bevel that was too convex - the kind that makes the belly of the bevel rest on the wood to be planed, instead of the very tip.

So, this is the first time that I've really used my big sandstone wheel for something other than puttering around:

264497

That's a relatively old photo; since then I've removed that tool rest and made a proper one that can tilt.

First I ground the iron's edge itself so that it was straight and square to the iron's sides (checked with a metal square) - the edge had acquired a camber that was a bit excessive for a smoothing plane. Then I set to grinding the convex bevel. I clamped a strip of wood to the tool rest to act as a guide. The stone is not perfectly true; it has a tiny bump where the chipped-out part is. But since I was pushing down on the iron, it rode the bump with little trouble.

Once the bevel had lost its belly and I was close to the edge, I went to the waterstones. 600, 1000, 8000... and the plane cuts like a dream again. I'm so happy to finally put this big grinding wheel to good use.

I guess I learned that grinding doesn't need to be ultra-precise. Initially I was worried that my grind would be uneven - and it is not perfectly even in the end. But it seems that as long as you take away enough material to let the stones do their job easily, you'll get a good, sharp edge.

[Harold Burrell]

Oh, wow! Cool grinding wheel! I really like the setup and thanks for sharing the process.

[Federico Mena Quintero]

Thanks! It was quite a find at an antique store in Puebla, Mexico. The seller seemed puzzled that I wanted it for actual use, not for decoration...

[Kees Heiden]

Yes, very cool!

Often when these things have been standing in water for several years the piece of the stone under water has gone all soft, making it unfit for use. But in a dry country like Mexico that's maybe not a problem? (Never been in Mexico, so showing my ignorance here.)

[Federico Mena Quintero]

Often when these things have been standing in water for several years the piece of the stone under water has gone all soft, making it unfit for use. But in a dry country like Mexico that's maybe not a problem? (Never been in Mexico, so showing my ignorance here.)

Well, at least this particular stone doesn't seem to have uneven softness. There is just a bump where the chipped part is. I think I'll run a wheel dresser on it at some point, but the whole thing is so big that the slight bump doesn't feel annoying - the blade just rides over the bump.

Apart from dirt and rust, the wheel seems to have been in good care. I just disassembled it, cleaned the bushings and all metal parts, and had a friend weld a handle to the axle - it was broken in one point, well past the bushing.

(Puebla *is* in the uncomfortably dry part of Mexico... presently I live in the sometimes-ridiculously-humid part, though) :)

[Kees Heiden]

The wheel dresser will probably just ride the bump too. Maybe it would be easier to use a diamond plate locally? Don't make too much dust though, it's not healthy for your lungs.