08-12-2018, 12:49 AM
(This post was last modified: 08-12-2018, 09:38 PM by KnifeGrinders.)
Oxidation is responsible for loss in sharpness by 5-10 BESS in the Victorinox/SWIBO stainless steel.
Effect of oxidation on sharpness >>
Grepper's sharpness numbers tell us that the clean leather not only straightens the apex, but also removes the oxidation, and the edge again scores the same as immediately after sharpening.
We've seen the same, for example:
Initial Sharpness 92 BESS > in 24 hours 100 BESS > after 2 strokes on a clean leather hanging strop 94 BESS.
I believe I've found out how to beat this post-sharpening sharpness loss phenomenon.
We already had indicators that higher-angle finish mitigates it, I only had to find the right combination. I shan't trouble you with the details - for SWIBO the following works.
The below Victorinox SWIBO knives were sharpened at 12 dps (24 degrees included), edge set on Tormek using a #1000 CBN wheel, then deburred on paper wheels, first with 5 microns diamond paste at a +1.2 dps higher angle, i.e. at 13.2 dps, and finished on a paper wheel with 0.5 micron diamond paste at +0.4 degree higher angle i.e. at 12.4 dps.
This higher-angle deburring resulted in about 10 BESS worse edge sharpness as compared to when finished at the exact edge angle ("initial sharpness"), but with little to none post-sharpening sharpness loss.
Initial Sharpness (BESS) - EDGE SEALING - Sharpness in 24 hours (BESS)
95 - none - 97
103 - Lanox MX4 spray - 99
93 - Tuf-Glide - 98
Edge sealing with the Lanox MX-4 has completely prevented oxidation as seen by the BESS scores, while the Tuf-Glide not.
Lanox MX4 is an Australian lanonlin-based heavy duty anti-corrosion lubricant, made by INOX, they have a sales branch in the USA.
Effect of oxidation on sharpness >>
Grepper's sharpness numbers tell us that the clean leather not only straightens the apex, but also removes the oxidation, and the edge again scores the same as immediately after sharpening.
We've seen the same, for example:
Initial Sharpness 92 BESS > in 24 hours 100 BESS > after 2 strokes on a clean leather hanging strop 94 BESS.
I believe I've found out how to beat this post-sharpening sharpness loss phenomenon.
We already had indicators that higher-angle finish mitigates it, I only had to find the right combination. I shan't trouble you with the details - for SWIBO the following works.
The below Victorinox SWIBO knives were sharpened at 12 dps (24 degrees included), edge set on Tormek using a #1000 CBN wheel, then deburred on paper wheels, first with 5 microns diamond paste at a +1.2 dps higher angle, i.e. at 13.2 dps, and finished on a paper wheel with 0.5 micron diamond paste at +0.4 degree higher angle i.e. at 12.4 dps.
This higher-angle deburring resulted in about 10 BESS worse edge sharpness as compared to when finished at the exact edge angle ("initial sharpness"), but with little to none post-sharpening sharpness loss.
Initial Sharpness (BESS) - EDGE SEALING - Sharpness in 24 hours (BESS)
95 - none - 97
103 - Lanox MX4 spray - 99
93 - Tuf-Glide - 98
Edge sealing with the Lanox MX-4 has completely prevented oxidation as seen by the BESS scores, while the Tuf-Glide not.
Lanox MX4 is an Australian lanonlin-based heavy duty anti-corrosion lubricant, made by INOX, they have a sales branch in the USA.
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