Using Onions to Patina Your Opinel?

7 comments by Igor Shteynbuk

Opinel Carbon Knife with Patina from Onions

Folks typically associate patina with years of use, visible wear, and long-term care. There is an aura of warmth and satisfaction when you see a beautifully patina'd Leica, lock-up bike, vintage car, tool chest, or leather bag. But not everyone has a few years to work a patina into their widget! Adrian found a fun article describing different ways to patina Opinel carbon steel and so we had to try it out. Some techniques involved chemicals, solvents, and such, but we decided on a more natural method - stabbin' onions. 

VO has been carrying Opinel knives for several years now. They're popular for their affordability, simplicity, and storied history as the go-to for French farmers, backpackers, and foragers. The carbon blade option does require more care and sharpening than their stainless steel offering, but carbon can take an edge easier. And because carbon is uncoated, they develop a nice patina over time. From Opinel: "Patina is completely normal and will help aid rust resistance of your carbon blade."

Here's what you need to create a beautiful patina on your carbon blade Opinel without years of use:

  • Opinel knife
  • Onion - white or red will do (we found no discernible difference in our test). Keep in mind you will be disposing of the onion once this process is done, so don't expect to use it in your next French Onion Soup or sandwich.
  • Water
  • Towel
  • 48 hours

Opinel Carbon Knife with Patina from Onions

Literally, stab the onion in the middle - all the way down the lock. We tried orienting the blade horizontally and vertically with respect to the layers of the onion and found inserting parallel to the root produced a circular pattern, while perpendicular was more wavy. Each of them is very cool. 

Opinel Carbon Knife with Patina from Onions
Opinel Carbon Knife with Patina from Onions

Now, the hard part. Put it down somewhere safe and where someone won't ask, "Why is there a knife in this onion?" Now leave it alone. The original recipe called for 24 hours, but we forgot and did 48 hours.

Opinel Carbon Knife with Patina from Onions

When the prescribed time has elapsed, pull the knife out. I will warn you, the knife will smell like onion. If you lived in an onion for 48 hours, you'd smell like an onion, too. But trust me, rinse it off with plain water and wipe it down. The smell will dissipate over the next day or so.

Opinel Carbon Knife with Patina from Onions

Behold your newly patina'd Opinel! 

Opinel Carbon Knife with Patina from Onions

After doing this experiment, Adrian found some more articles about creating patina on Opinel knives. My favorite was simply drizzling McDonalds spicy mustard sauce over the blade and letting it sit for a bit.

I'm thinking about how to patina the Blue Lug Brass Spacers. Any ideas?


7 comments


  • Nicholas

    Why not just chop up some onions and put the spacers into a ziploc plastic container with them for the same effect. Or just install them new and ride the bike for years until they patina anyway :-)


  • Ron

    When I wanted to blacken the blade on a carbon steel knife I was making, I heated up some vinegar in a small glass jar in the microwave. I then immersed the blade in the hot vinegar for a while. When it looked right, I pulled it out, rinsed and dried, and oiled the blade. Presto!


  • Scott

    Brass is easily aged to a beautiful mustard brown color by fuming with ammonia. Suspend the parts in an enclosed container with a splash (about a cap full) of ammonia at the bottom, put on the top. Gently warm the container from below, I usually use an incandescent light bulb but any source can do, just warm it. The ammonia will make fumes around the parts and in just a few minutes, maybe only seconds the parts are aged. Rinse with water and throw out the ammonia. Warning, don’t stick your nose in the fumes, it’s not pleasant at all. If the color isn’t what you want then polish the brass and try again.


  • Dean Horsfall

    I like the idea of a brass top cap upside down on an onion centre for a day. Seems like a fun thing to do! Thanks VO


  • Matte

    Interesting! I used vinegar and salt to kickstart the oxidation on the brass bits I got from you.


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