Thread: Light Reflection Test (LRT) - on bevel setting

Forgive me if I am stating the obvious, but here goes.

I wanted to raise conversation on bevel setting issue I struggled with in the beginning of my razor honing. I have had a very hard time going from some sensations on the thumb-nail-test (TNT) and cutting arm hair test (AHT) to getting the sticky feeling on the thumb-pad-test (TPT). Given that the above tests are very objective and require experience to interpret correctly led me to constantly hope that I had bevel set when in fact I had not set bevel. The test that finally allowed me to zero in on setting the bevel and getting TPT and TNT truly pass was the light reflection test from the edge (LRT).

First I took a kitchen knife and looked at the reflection, which obviously was very wide and strong, to give me an idea what is not wanted. Then I took one of the razors I had been trying to set bevel on. The reflection was still very pronounced. At that instant, I knew that I was not yet close to having bevel set. As I kept patiently honing and checking under light I could see the reflection go smaller and fainter gradually. And sure enough, when the reflection was very faint, the TPT started passing too. If there was no improvement, occasional backhoning helped to clear any burr/wire-edge and allowed to progress forwards.

I think this test can be very useful to beginners, like me, and to some degree to the more experienced honers when setting the bevel. I had read the wiki and watched many of the videos, and nowhere was it clearly stated and illustrated that this kind of test could be used to assess the edge. Of course this test is not bullet proof, but should a be seen as an additional tool to the existing tests.

I took couple of photos and made a crude illustration to explain the test. The razor should be held under a strong light (like led flashlight, or countertop light) so that the light itself does not blind the viewer. Then the angle of the razor should be varied and at some angle there will be a reflection. Dark background helps to see the reflection.



And here is an actual picture of a reflection when the bevel is not set.


Moreover, if a magnification device is available, the actual edge width can be examined viewing it directly above with the help of a strong light.

I hope this proves useful to others who are struggling in the beginning. Especially if you are trying hone those ebay razors.