Sharpening Dendritic Cobalt. A Boye knife.

F

Fir Na Tine

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Nov 1, 2020
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348
Calling all Boye owners!
Bringing up an old thread because I am purchasing an old Boye knife from the 80s from when he still had his shop in the Santa Cruz area of Davenport in California. It is a Francine etched drop point hunter with an Ironwood handle and I am trying to learn the best way to sharpen it and maintain the edge. What I am gathering is it is designed to have a more more “toothy” edge because of the properties of the cast. Question is, will the newer one side toothy and the other polished give this knife the best of both worlds result? Is a DMT fine stone ideal for this knife? I hear that this knife is not tough, but what other metals would you liken it to so I keep it within its limits and not break or chip it? My initial thoughts were to get it to a mirror edge, but after reading this thread, it seems it needs to have at least one side “toothy” and let it develop a saw tooth edge but is that still the best understanding for this knife? I am trying to adapt to the knife and not adapt the knife for me and use as intended or within the unique qualities but I do love a fine edge. Also, what is the best way to sharpen in terms of how you stroke it on the sharpener in terms of how hard you press and only one direction perpendicular to the edge, etcetera.
Thank you for your input.

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A few smudges from some use. This will be a “BBQ” or special occasion knife. My guess is the valve may be around $600? I have seen similar knives listed for about $750
 
Fine diamond stone, light touch...use it on a wood cutting board and it will damn near never need resharpening. This reground Basic 4 is the most used knife in the kitchen.

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Wow!
Cool knife with the regrind.
What do you think about stroping? Will that help or hinder the edge?
Did you regring that one personally?
Thanks
 
Shouldn't need it if you don't raise a burr...I never do🤷‍♂️
 
Yup, I did the regrind...DMT fine (red) is what I use.
 
BDC and BDS are David’s favorite blade materials. Boye Dendritic Cobalt is Stellite 6-B which is about 1/2 Chrome and 1/2 Cobalt. This material has a low HRC (Hardness Rockwell C scale) around the low to mid 40’s and contains no hard Carbides. The edge tends to roll rather than chip when stressed. It is easy to restore a rolled edge pulling it (edge trailing) over a small diameter water pipe or brass rod. When the blade is poured, it develops macro crystals in the micro edge as it cools. These are called dendrites and give the edge its toothiness. Because of the crystalline nature of the micro edge, it does not lend itself to fine polishing.
The Boye Dendritic Steel is 440-C which is also poured and develops dendrites. This alloy is capable of HRC 60, so it is probably more prone to chipping than BDC. I sharpen BDC on 2000 grit Shapton Glass stones. They are Al2O3.
 
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