Thread: No pressure means no pressure...

Today I was honing a full-hollow Friodur that is in good shape but has a very slight frown, and I was applying some pressure on a barber hone. The light happened to be hitting the blade at just the right angle, and holy cow, I could see the razor flex around the corner of the hone.

It looked like a ripple in the blade as I worked my way down the hone. I guess I wasn't holding the razor as flat as I thought, and the pressure was really flexing the blade. That can't be good.

I'd always thought that the blades were much more rigid.

Lesson: Keep the razor flat, and use light pressure. Very light!

Josh

Originally Posted by joshearl

I'd always thought that the blades were much more rigid.

They are, but the very thin edge is very thin, so it flexes. This is true for wedges as well as extra hollows, though I've had extra hollow blades so thin that any pressure at all and you could see the entire blade flex at the secondary grind.

I use this to help me evaluate an edge - hold it so the light is just a few degrees away from reflecting off the bevel into your eyes, then run a fingernail underneath the bevel flexing it up and watching for unevenness in the reflections from the fin. Generally an overhoned edge will keep reflecting into your eyes after your fingernail has passed by, and microchips show up as a dotted-line effect. You need a good point light source for this, like an incandescent bulb 5-6 feet away, or the sun.

I find I can usually see a wire edge as well. I have a nice halogen desk lamp that works well for this. Usually when I can't get an edge sharp in one or more spots I look at it under the light. If you can see a tiny line of reflected light along the edge, it's either a wire edge or a tiny secondary bevel.

Josh