Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
I just updated this with a check to see how the results of an edge retention comparison would be effected by corrosion, so I subjected a Sebenza, Calypso Jr. (ZDP-189), Meadowlark (8C13CrMoV) and Rucksack (INOX), to a fairly corrosive soak for 16 hours and then did some cardboard cutting.
Even though there was at times heavy visible rust, this didn't correlate well to the edge retention. It was just a roll of the dice on if the edge itself got effected and there were times when a knife with little visible rust was significantly reduced in edge retention as well as the opposite.
Overall, based on what I saw, I would pick the Sebenza if I had to cut a lot of cardboard or other abrasive media in such conditions as while it did rust more than the SAK, it on average cut better and was easier to sharpen due to the hollow grind. However I would want to see the results of this done at least one more (another four rounds) before I would be reasonably confident.
The Sebenza actually sharpened as fast with a 800 AO hone as the others did with the 200 grit SiC which shows the difference that primary profile can make on speed of sharpening, totally masking the difference in machinability. It was faster to refile the SAK with a bastard file, then sharpen on stones due to the low hardness.
All primary edges were similar with 5/10 degree profiles (five degree primary edge with a 10 degree convex sweep due to mainly the SiC stone developing a hollow) with a 0.1 mm micro-bevel set at 20 degrees on the medium rods. It would be interesting to see if a higher polish on the microbevel would effect the results. I have a bajillion other things to look at first though.
Note none of these knives have profiles similar to the NIB ones, the corrosion rates seen here are *MUCH* worse because of the heavy scratches, especially noted on the Meadowlark. The Sebenza also has a slight recurve due to sloppy sharpening and the Calypso Jr. has lost a lot of metal off of the edge through extensive use/sharpening.
http://www.physics.mun.ca/~sstamp/knives/small_sebenza.html#corrosion_resistance
-Cliff
Even though there was at times heavy visible rust, this didn't correlate well to the edge retention. It was just a roll of the dice on if the edge itself got effected and there were times when a knife with little visible rust was significantly reduced in edge retention as well as the opposite.
Overall, based on what I saw, I would pick the Sebenza if I had to cut a lot of cardboard or other abrasive media in such conditions as while it did rust more than the SAK, it on average cut better and was easier to sharpen due to the hollow grind. However I would want to see the results of this done at least one more (another four rounds) before I would be reasonably confident.
The Sebenza actually sharpened as fast with a 800 AO hone as the others did with the 200 grit SiC which shows the difference that primary profile can make on speed of sharpening, totally masking the difference in machinability. It was faster to refile the SAK with a bastard file, then sharpen on stones due to the low hardness.
All primary edges were similar with 5/10 degree profiles (five degree primary edge with a 10 degree convex sweep due to mainly the SiC stone developing a hollow) with a 0.1 mm micro-bevel set at 20 degrees on the medium rods. It would be interesting to see if a higher polish on the microbevel would effect the results. I have a bajillion other things to look at first though.
Note none of these knives have profiles similar to the NIB ones, the corrosion rates seen here are *MUCH* worse because of the heavy scratches, especially noted on the Meadowlark. The Sebenza also has a slight recurve due to sloppy sharpening and the Calypso Jr. has lost a lot of metal off of the edge through extensive use/sharpening.
http://www.physics.mun.ca/~sstamp/knives/small_sebenza.html#corrosion_resistance
-Cliff