Thread: Honing Sketch

In Straight Razor Place Wiki there is a text about 'Bevel-setting in theory and practice'. The website link is Bevel-setting in theory and practice - Straight Razor Place Wiki

I do not understand the sentence 'But in our real world practice, we use flat abrasive tools, and those tools are only effective with flat bevel sides that lay in the same field as the imaginary field that touches the spine and the edge'.

Can someone please illustrate this for me with a sketch?

Thanks in advance.

I don't have enough time right now to make a sketch that would look any better than something my kids brought home from kindergarten.


Rephrased though:

In theory, a razor with a convex bevel could be honed on a concave hone with curvature that matches that of the bevel.
We use hones that are flat, therefore we need to have the bevels on our razor flat in relationship to the spine, so the hone is working on the bevel using the spine as a guide.

Maybe plane would be a better word than field in this case

Ok, so I threw together a sketch:

In the one on the left, the bevel is convex - it could be honed on a concave hone, but a straight line (flat hone) passes through the convex. That area would need to be ground away to work with a flat hone.
In the one on the right, a straight line connects the bevel and spine - this is what's desired when we hone.

Is it correct to say that the razor shown in the left drawing can also be honed on the hone shown in the right sketch? But not in reversed order?

Or in other words, you can hone every razor on a flat hone?

The one on the left could be honed on a flat hone - it will require grinding away the convex to get it flat all the way to the edge.
You would do that when you set the bevel on it. I guess the short answer is yes - any razor of good quality steel can be honed on a flat hone. Some will require a little more work to correct bad geometry.

Technically, the razor on the right could be honed on a concave hone, but every hone in the progression would require the exact same concaved surface, which is virtually impossible to accomplish in reality, and it would convex the bevel, requiring a new bevel set any time it was honed on any other hones.

Why is the convex stuff in the Wiki at all? What is the point? Who would hone on a convex surface? How do you ensure it retains the exact radius of curvature as it "dishes" over time? There's a reason we hone on flat surfaces.

James.

I think it's there to help establish the importance of flat hones.

HNSB, hoglahoo, Jimbo, thanks for your input.

Now that we are discussing honing issues, I have another question. Probably one that is harder to explain.

I do not understand the whole text shown under the headline 'Troubleshooting'. No matter how often I read this paragraph, it doesn't make sense.

Is there a better method to explain what point is made in this text?

Well it has certainly convinced me of the stupidity of convex surfaces...

James.