Thread: Honing Sketch

Originally Posted by Jimbo

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

James.

I am not sure I understand the idea of wanting to create a convex edge on a razor...but a lot of them are these days either from stropping aggressively with abrasives or adding tape for the finish hone (Zowanda method, I think)...technically they may be more of a complex bevel than a smooth convex...but hopefully you get the point.

OTOH, I would not be quick to say convex surfaces are stupid...it is pretty easy to see that there is a bit more support behind the apex on a convexed edge and they tend to be a bit more durable in some regards (so long as they work well on your face)

Originally Posted by strtman

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?

Yes. Sometimes edges are screwy because the razor is not a perfect triangle. Imagine the blade is a triangle with the spine as the base and the edge as the apex. On some razors the apex is not perfectly centred with regards the base. On other razors, the sides of the triangle are not perfectly straight lines. On some razors, both problems occur. On some razors, the issue can be quite extreme, though I have never seen (as the author of the wiki article states) a grind issue so bad that only one side of the bevel can be sharpened unless it is by design, like those Japanese blades or the microtomes or whatever they are called.

The idea of honing is simple: rub both sides of the edge (the bevel) on an abrasive (flat) surface until the sides meet at a "fine enough" point. "Fine enough" can be pragmatically defined as whatever produces a shaveable outcome. Obviously, when each side of the bevel is taking turnabout on the hone, whether each side has the same amount of metal touching the hone becomes a consideration. Under certain circumstances, remedial measures are necessary on the hone. The rolling X-stroke is a way to undertake those remedial measures in some circumstances.

James.

Originally Posted by unit

I am not sure I understand the idea of wanting to create a convex edge on a razor...but a lot of them are these days either from stropping aggressively with abrasives or adding tape for the finish hone (Zowanda method, I think)...technically they may be more of a complex bevel than a smooth convex...but hopefully you get the point.

OTOH, I would not be quick to say convex surfaces are stupid...it is pretty easy to see that there is a bit more support behind the apex on a convexed edge and they tend to be a bit more durable in some regards (so long as they work well on your face)

The surfaces are not stupid, the idea that you can maintain a hone with the exact radius of curvature necessary to impart precisely the same curvature on the razor each time you hone it is stupid. It is hard enough to lap a hone flat, let along make sure it maintains a certain curvature its entire life. Of course, you can accomplish it with some kind of rotating lapping wheel of certain radius, but I'll leave that to the experts and get by with my flat diamond plate.

Zowada 'adding tape' bevels are piece-wise linear bevels and are, from my reading of his posts at the time, a way for him to hone produced razors more quickly. The "robust edge" rationalisation came later I think, though I could be wrong there and apologies if so. Convex edges produced with pastes on on yielding strops are a side effect, not the primary goal. I also think Glen figured out that the convexing is minimal to the point of negligibility when considering the micron levels of something like CrOx paste compared to a bevel setter. But again, perhaps I don't remember that absolutely correctly.

James.

Jimbo, slow but sure it is all starting to make sense. Thanks for your extensive answer.

Originally Posted by Jimbo

The surfaces are not stupid, the idea that you can maintain a hone with the exact radius of curvature necessary to impart precisely the same curvature on the razor each time you hone it is stupid. It is hard enough to lap a hone flat, let along make sure it maintains a certain curvature its entire life. Of course, you can accomplish it with some kind of rotating lapping wheel of certain radius, but I'll leave that to the experts and get by with my flat diamond plate.

Zowada 'adding tape' bevels are piece-wise linear bevels and are, from my reading of his posts at the time, a way for him to hone produced razors more quickly. The "robust edge" rationalisation came later I think, though I could be wrong there and apologies if so. Convex edges produced with pastes on on yielding strops are a side effect, not the primary goal. I also think Glen figured out that the convexing is minimal to the point of negligibility when considering the micron levels of something like CrOx paste compared to a bevel setter. But again, perhaps I don't remember that absolutely correctly.

James.

I think I could agree with everything you say.

I would agree that a few stroppings on micron sized compounds would make only for a very slight convex...but it is slightly convex...and after MANY repeated stroppings the edge will convex considerably. Though, I am not sure anyone plans this intentionally

I would only suggest that in the world of cutlery, convex edges are quite a bit more durable. I am not suggesting that this concept could be applied to razors effectively, conversely I am not sure the concept can be completely dismissed until someone tests it thoroughly either. I have always been one to discuss symantics...and to your very valid point...trying to accomplish this with hard media does seem questionable for the average guy.

Sorry to ramble on an idiotic topic...but I will share that I watched an episode of "How It's Made" where they were making disposable razor blades and they had a series of bevels that I would characterize as "complex" and essentially was a "digital" representation of a convex bevel (i.e. a stepped collection of bevels that approximate a convex)...so it would seem that there may be some merit to the idea (if you have highly complex grinding equipment at your disposal)

Originally Posted by strtman

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?

The troubleshooting section is for razors with warped blades. There is probably a better method, but I don't know what it is

Looks like the editor is out again but I will try

Just to clarify my above posts: neither convex bevels or concave hones are desirable, in my opinion.

What it means is the spine and the bevels should lie flat on the stone.
That can happen only if the stone is flat and the razor has proper grind. Unfortunately all the requirements are not met all the time. Most notably the razor may not have been ground perfect or was improperly honed, then it will not completely lie flat on the stone.

Just to recap, a very flat stone, with a very flat razor, rub together, strop and shave/ repeat if needed.

Your welcome, tinkersd