... parts of the cutting edge and the spot on the spine where my thumb rests seem to rust regardless of how much I clean and oil the blade after work. I read a little about blades eventually gaining a patina that improves corrosion resistance but was wondering if I could help that process along. Are there any techniques or tricks to force a patina?
I'd say stop cleaning and oiling the knife so much. By polishing and oiling the blades all the time, you're not letting a patina develop. Take, say, two or three weeks and just keep a wee drop of oil on the joints (something you should do with any folding knife), but lay off the washing-and-oiling routine.
Unless they're going into storage for awhile, I
never keep a sheen of oil on my carbon blades. If they get gunk on them or are sticky from cutting an apple, I'll run some warm water over them in the sink (just on the blade, not down in the joints), then wipe 'em clean with a rag or t-shirt or bit of toilet paper. Spit works well too.
That's it. I think the need to keep oil on carbon steel is way over-stated. Just keep the blades dry.
... if so, will it be as effective as a natural one?
I do put a "pre-patina" of sorts on most of my carbon steel knives as a way to ward off rust, something that my grandad -- who spent his entire adult life as a glass man in Miami, Fla., and then retired to Okeechobee -- did as well. However, I
don't believe it to be as effective as a natural one.
However, that's really a false question. A knife will only develop a true natural patina after lots of time and use. Just by way of example, let's say 3 years. If you have two brothers and give 'em each the same model of carbon steel pocketknife but one is "pre patinaed," assuming they use and maintain the knives in the same way for 3 years, at that point, I'd bet dollars to donuts you couldn't tell which was the pre patinaed knife. Both knives will have that nice "earned" patina look.
-- Mark