Aargh! Now what?

[mbrossar]

Okay, clearly a newbie honer with a clear newbie question. Without going into too much background, I'm trying to reset a bevel using a coti (although this problem could probably be on any stone). I'm following the Unicot process as described on coticule.be. I notice as my razor starts to shave my arm hair, it shaves effectively at different angles on each side (i.e. I can shave the hair on one arm at about a 20 degree angle but on the other arm I can only shave the hair at about a 35 degree angle). What does that mean? I suspect it means the bevel's bigger on one side than the other, and that I need to spend more time on one side to balance it back out, but I'd rather not guess at it. Any advice on what's going on and what I need to do next?

On a related note, how do you evaluate the size of the bevel on each side? Do you use a magnification device such as a loupe, reading glasses, etc or can you tell with your naked eye (not that I can )?

Thanks.

 

[holli4pirating]

I have found that before the razor is fully set, may cut hairs differently from each side. (I do not know if this is what is happening for you, though.) My suggestion would be to keep going in "bevel setting mode" until you can cut arm hairs rather easily at a normal shaving angle with the razor either way.

The size of the bevel is not important; so long as the bevels meet at a good edge the razor will shave. Uneven bevels can be the result of uneven hone wear, uneven grinds, uneven honing, etc etc.

 

[mbrossar]

Thanks. That gives me some confidence to proceed.

 

[Bart]

I notice as my razor starts to shave my arm hair, it shaves effectively at different angles on each side (i.e. I can shave the hair on one arm at about a 20 degree angle but on the other arm I can only shave the hair at about a 35 degree angle). What does that mean?

It's a weird occurrence . The are a number of situations that can cause something like this, but not what you are assuming. The very edge does not know what lies beyond. As long as both bevel panes have the correct angle, it doesn't really matter how wide they are, or how much their width differs. An edge is just a wedge that penetrates between hair cells. It the wedge points in the right direction, it'll sever the cells.

Now, what makes an edge point in the wrong direction?

1. stropping mishap (not your case). Faulty stropping can make an edge bend to one side a bit.

2. a chisel-type bevel, meaning only one bevel pane like you see on a wood chisel. Behaves completely different on one side than on the other. Very unlikely on a razor (except a traditional Japanese one)

3. a razor with a completely asymmetrical spine, which would result in bevel panes with different angles. I haven't seen one yet where to problem would result in a noticeable difference.

4. (maybe part of your problem) remnants of a previous bevel with different angle or heavy convex. It's possible that you've only fully reset one side and the other side still carries the edge portion of the previous bevel. That can cause asymmetrical angles, with some difference between the ideal cutting angle at either side of the razor. But it doesn't explain the 15 degree difference you describe.

5. (maybe part of your problem as well) If the spine is accidentally lifted for as little as one stroke, a secondary bevel at that side is created, at much steeper angle than the spine touching the hone. If that one stroke happens at a fairly constant angle, that tiny secondary bevel might even offer considered keenness. Yet at a completely different cutting angle. Depending on the length and speed of the hone and the applied pressure, it may take many strokes to undo that small secondary bevel, certainly if the rest of the bevel is a wide one, because it must entirely be brought down to the level of accidental secondary bevel.

Any advice on what's going on and what I need to do next? How do you evaluate the size of the bevel on each side? Do you use a magnification device such as a loupe, reading glasses, etc or can you tell with your naked eye?

Magnification could be helpful, but even without it, careful inspection of the edge can reveal a lot. Let a decent light source shine on the blade. Twist and turn it till you see the reflection of the light. A good bevel shows only one reflection. Twist the blade by the tiniest amount and the reflection moves out of your eyesight all at once. If you see two reflections at a different angle, there's the new bevel and the old one at different angle, still living near the very edge. If you see a faint line of light sprouting off the very edge, there's some convexity left from prior pasted stropping, or just rounded dullness. With some practice, you can really tell a lot, by simply looking at an edge with a good light source. Often even more than with magnification.
Try to figure out which side of the bevel is still off, and work on it. Don't presume that it's the smallest side. It's typically the widest side that takes more work to straighten out. Yet it doesn't hurt to work on the smallest side as well, in an attempt to keep the edge centered. Though this will not affect the shave.

Best regards,
Bart.