Wednesday, August 31, 2011

Rigging Knives

As many of you know I am a bladesmith (Ben Potter, Bladesmith, Privateer Armoury ) and have been working on sailor and rigging knives. I thought I'd post about the progress here as it is pertinent. Today I was testing one of the knifes that I have selected as a possibility modification as a sailing knife. As a sailor I wanted to know not only how the blade would perform for normal use but to push it way beyond what it should ever experience out on the water. I didn't wast time on the finish as I planned to do destructive tests. You can still see the heat colors from softening part of the spine of the blade. The first test was to clamp the blade in a vice and snap the tip off. I used a 6# sledge hammer and it took 6 hits (none of them soft) before it broke. I then did some minimal grinding on the profile and sharpened the blade for the "cutting" tests.
Here are the results.
Blade testing: clockwise from top right: 3/4 nylon rope, insulated solid copper wire, 12ga extension cord, 1/2" marine plywood, stainless steel control cable, 1/16" stainless steel, 1/8" stainless rod, 16 penny nail, 1/2" rebar, 1 1/4" hardend steel well drilling cable.
The knife cut through all the non-ferrous materials with surprising ease no damage whatsoever. The rope, wire, and extension cord were cut with out any additional tools other test pieces were cut with the aid of a 5# sledge not because it needed that much forge but I wanted to test the blade with a greater impact than would be seen in normal use. Having worked with the plywood in the past I was expecting a more difficult time cutting it but it parted without a struggle. When cutting the stainless there was slight dulling of the edge but no chipping. The steel nail did leave some deformation as is to be expected. After the cutting test I decided to see what the limits of the blade were. The first victim was a piece of 1/2" rebar. Laying the edge on the bar and striking the back of the blade with the sledge. The edge bit into the rebar but in turn suffered moderate deformation but there was no chipping or cracking. During the stainless cable test I cut trough the cable and into the cutting face of the anvil, then continued to pound the back daring the blade to twist or break. The only test that the blade had any trouble with was the hardened well drilling cable (I was not aware that it was hardened until after the test) which did take a small chip out of the edge. All in all I was very impressed with the quality and look forward to crafting quality sailing knifes from these blanks.
I should mention that I was wearing full protective gear (full head/face mask. leather apron, gloves etc.)as I expected the blade to shatter during the testing from the impact and severe torsion from the round faced
hammer blows. DO NOT  ATTEMPT ANY OF THESE TESTS ON YOUR OWN AS THEY ARE EXTREMELY DANGEROUS and WILL damage any knife subjected to them!!

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