cutting

[davebolton]

Ed, how did you test the cutting qualities?

Who many times was the blade resharpened an then tested?

[Ed Caffrey]

Hi Dave!

If your talking about the tests done on the "blue" knives, I test cut on a 1/2" piece of hemp rope, with a piece of 2x4 under it, and all of that set on a digital bathroom scale. Zeroed it out, and then started cutting. When it required more than 30 pounds of pressure to cut the rope, I considered the blades dull. I resharpened and conducted the test two more times to get a bit more accuracy. All three of the blades where from the same bar of mosaic. Blade #1 was not sujected to the Nitre Blue, Blade #2 was in the Nitre Blue for 3 mins, 40 seconds (this was where the nice, bright blue appeared). Blade #3 was in the nitre blue for 5 mins even. I did a few more little tests and discovered that after the 5 min mark, the cutting ability of the blade drops way off.
In short the 3 min, 40 second time in the nitre blue produced about a 10% reduction in cutting ability on the hemp rope, while the 5 min time in it, nearly killed the blades cutting ability.
Actually I was pleasently surprised, as I expected any blade sujected to the Nitre blue to be worthless for cutting. Just more proof that Time and Temp really are everything when dealing with blades!

[davebolton]

Thanks for the info. Ed, that is very disappointing news to a knike maker who always has had the desire to blue my own blades.

Are there any other methodes less detrimental?

[Ed Caffrey]

Actually I feel that the Nitre blue is the least damaging of the available methods for bluing, unless you go with cold bluing. I personally don't like the looks of most cold bluing, as it is more a black than blue. I do keep Brownell's 44/40 cold blue in the shop.....it's the best that I found so far, both for color and for durability.