Sharpening

[Cobalt]

Thought I'd drop this here for anyone who hadn't seen it yet:

http://www.bladeforums.com/forums/s...f-an-edge-during-belt-sanding-initial-results

The OP is experimenting on power-grinding using the WSKO and temp-sensitive lacquers to indicate heat-level at the apex, with a deliberate effort to over-heat the edge. Bluntcut made some recommendations that he should implement - use hardened steel against finer-grit belts - but the initial results are interesting.



I sharpen my larger blades on an HF 1x30, some of my smaller ones as well, though I do have a DMT aligner set for making pretty even bevels or sharpening when not at home. If I'm hurting my edges on the HF, I've not noticed it yet. YMMV?

Very good thread link, thanks.

First a very coarse belt produces less heat. The finer the belt the more heat. I would love to see him test with a fine belt and do so on a stainless blank. Also not sure how a heat treat affects heat conduction but it may resist it more which as I say below can be worse for the user.

A metal that conducts heat faster dissipates it faster and you are more likely to notice the heat in your hand. For example, my simple carbon steel blades like 1060 I can heat the edge up very fast on a belt sander. My stainless blades take much longer to heat up to the touch. The issue here is that while I can reach high temps in the plain steel faster, I will notice the heat faster as well and stop before there is damage. With a stainless or high alloy steel that resists heat conduction, it may take more time to burn the edge because the alloy is more heat resistant, but I am more likely to damage the edge because I do not feel the heat in my fingers as soon while holding the blade.

Some of the knife makers in that thread claim that you can burn an edge without even feeling much heat in the blade at all. I don't see how that is possible unless the blade is so thin that the edge will flash to a high temp very quickly. But I would think that n anything other than a razor that would not be possible.

I love it when people perform tests like this. It sure goes a long way to indicating that it is not so easy to burn an edge in any event. I have burned plenty of cheap knife edges on a belt sander. But I was checking to see if that would happen in the first place.