Wire Edge Prevention

[KnifeGrinders]

The two knives in live boning:



Feedback:
"The knives were very sharp to begin with, and kept the edge well, but only for a couple of bodies. I would say the test knives lasted about half the time my own knives usually last."

The butcher's own knives are the same kind of SWIBO and VICTORINOX boners, the only difference is that he sharpens them on benchstones, deburring with a fine-cut steel.
While his own knives last through 4-5 steer carcasses (with steeling), our test knives lasted for 2 carcasses and performed well, though for a shorter period.

This tells us, firstly, that the knife is free of wire edge and, secondly, that the edge strength had been compromised in the process of sharpening, and therefore dulled sooner.
If the knife had had a wire edge it would have been discarded after first cuts; a crushed wire edge cannot be steeled back to sharp.
Professional use of knives includes both cutting and frequent steeling.
Cutting dulls the edge through rolling and abrasive wear, while steeling recovers the edge back to sharp.
Steeling keeps the edge sharp mainly by microbevelling and removing metal, and the softer is the steel the sooner the edge gets steeled off to unusable.

I blame this edge softening on the felt with Autosol causing overheating as it is run on a half-speed grinder at about 1400 RPM and is the only sharpening step I can think of blaming. I know of myself that when deburring knives on that felt wheel I neglected the common rule for high RPM that "Better do 2 quick passes than 1 slow" - being too focused on the edge angle control, I was slow in sliding the knife across, gave the knives 2 slow passes each side and could feel the blade warmed up. I hoped that slots in the wheel would mitigate the overheating, and they do but obviously not well enough.
To improve the edge longevity I should reduce the knife contact time with the felt run at high RPM.

As to the wire edge removal this trial concludes our experiments nicely, and confirms that deburring at a 1-2 degree higher angle cleans the apex of the base burr not rounding it.
The proper deburring requires minimum 2 steps: first honing at the edge angle to thin away the burr, and then at a 1-2 degree higher angle to clean the apex.