One winter evening, I had a discussion with my dad dealing with hunting and woodworking knives and the steels that make them. As a result of that discussion, I realized that my knowledge of metallurgy doesn’t go beyond “smelt iron with carbon and you get steel”. I decided to look into understanding different steels and what makes one better than other, which lead to steel composition, which led to heat treatment process, which led to a variety of topics, such as; blacksmithing, knife grinding, heat furnaces, oxidation protection, Japanese blades, sanding/grinding machines, edge geometry, sharpening, etching, and so on. While this was a fascinating intellectual trip, it also made me want to get my hands dirty and actually make something.
I decided to start small and make a couple of pairing knives using stock removal method:
#1 Front
#1 Back
I designed the shape of the blade using Photoshop’s vector graphics with an aesthetic goal in mind and hoping that it would be somewhat functional as well. The shape is all curves with no straight lines. Although I am pleased with the how knives look, it would benefit from a narrower blade for everyday practical use.
#2 Front
For the steel I used O1 1/16″ thick stock which I then heat treated to 60 HRC using electric kiln for austenitizing and kitchen oven for tempering. I don’t have hardness testing equipment so I can vouch for 60 HRC (at least that’s what I should have theoretically). Blades have been mirror polished using black and white rouge. As you can see below I still have to master my sanding techniques – there are a lot of deep scratches that polishing does not hide. I’ve etched both blades using electrolysis using nail polish lacquer for ground. Again, a lot of mistakes made and a lot learned from those mistakes. Nail polish lays down thick but chips when scratched producing jagged edges. Electrolysis is fast in removing metal but does not produce an even etch.
#1 Blade
#1 Blade
#2 Blade
#2 Blade
Guard is made out of brass and again i avoided straight lines which made the job of fitting it with the handle so much harder.
Handle is made out of Jatoba or Brazilian Cherry which i sawed out of left over parquet planks. Jatoba is one of the hardest woods in the world and makes for a heavy handle. I sealed it with Tung oil and wax. Another lesson learned – tape the wood completely before polishing to prevent black polish and metal particles from getting into the wood pores.
#1 Handle
#1 Handle
#2 Handle
My choice of O1 was dictated mostly by availability and price and although i was aware that it easily rusts i was planning on taking a good care of it and not letting it be rust. Well, after couple of months of use here are results:
After months of use
Rusted Closeup
Rusted Closeup
The blue-gray-yellow background is patina expected from regular use and even valued by some knife-enthusiasts. This patina appeared almost immediately. The rusted blotches however are the result of leaving the blade with some water on it for couple of hours. The patina and rust does not reduce cutting qualities of the knife as long as rust is not on the cutting edge. However pits caused by rust will invite more rust and a place for bacteria to hide. Hindsight, the non-stainless steel is not a good choice for the pairing knife since it is used frequently and for short-duration jobs, so wiping it off after every use can quickly become tiring. However after 10 minutes on the polishing wheel, the knife can be restored back to it’s former glory (almost):
After Polishing
After Polishing
Tags: jatoba, knife making, o1, pairing knife, patina, rust
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