Carbon Steel and Condiment Patinas

I like the appropriate use of confusing titles as much as the next guy, but this post has a deserving one. If you are here because you own or want an Opinel classic, then my search engine optimisation is not too bad. Firstly, welcome to affordable, simple, moddable and genuinely fun knife ownership. Secondly, allow me to disclaim the intention here.

As always, I am not sponsored; but biased. I am not the average user. I have specific needs from my things. Opinel is a manufacturer of knives, based in France. They have been making knives since 1890, and they sell around 15 million of them per year. It seems that the owners of these knives are extremely fond of them, and I can vouch for that fact. Whether you like stainless steel or carbon steel, they have them. Personally, I do not care much for any products other than the No6, 8, 9 and 12. I am confident in all of them, but I just don’t have a need for those. My uses and interests lie with practicality, daily-use (EDC), bushcraft and farm-use. So, with that said…

My friend recently received his “reasonably priced steel” MoraKniv, and it prompted us into discussions about the stainless and carbon-steel world. Some people prefer the one over the other, and I am just simply happy with carbon-steel because it sharpens to insane levels for me. It seems to hold it’s edge longer, and mostly because that is what my first Opinel came in. The flipside to carbon-steel is that it is not resistant to stains and rust(oxidation) and will show a messy patina over time.

Patina? That is the stains and film that builds up over metals as they oxidise and wear. Fruit, meat, wood, pelts and whatever else you cut and slice with your blade will have an impact on your carbon steel. Everything has some level of acidity that will affect the look of the blade. I got used to this messy look, it’s like a historical journal of the blade’s past. There is something else however, that came to mind. Forced Patina’s. You can effectively create (force) the oxidation layer on to the carbon-steel which looks uniform and also protects the blade against stains and rust going forward.

As you can see here, the blade is covered in red, blue and black marks and stains. It is just over a year old, never been sharpened past factory edge and it is what it is.
I decided to investigate the sharpening process and restore my blade to a hair whittling edge. A forced patina by submerging the blade in boiling vinegar or something acidic like tomato juice might follow.

Various sharpening methods exist. Blade owners swear by some, support others, tolerate a few and hate the rest. Ask any five knife owners, and you will get seven opinions. What they say makes sense, however. You get whetstones, dry stones and a myriad of awesome devices from makers like Lansky. In the end, it seemed, sandpaper was the way to go for me. The constant bevel of the Opinel and the materials that sandpaper is made from just simplifies it for me. I set out to buy sandpaper from our local AgriMark and found most of the grits I wanted: 600, 1000, 1200. Unfortunately, the grits smoother than 1200 is extremely rare in hardware and agri-shops.

The second thing needed, was a piece of leather and my tube of Autosol. I opted for Autosol simply because I can also not find the honing compounds I really need. Think of Autosol like very, very fine sandpaper. The process was simple enough if done with care and attention to the bevel angles and steps. I really recommend watching videos and reading about this yourself. I do not want to give advice on how to sharpen, especially since I am not an authority on sharpening at all.

After 1000 grit sharpening

After about 40 minutes of work, correcting the edge and then smoothing the blade step-by-step, I ended up with a rougher looking but definitely sharper blade. It’s not hair-whittling sharp, but I will retry and redo the process once I have better materials on hand. The Autosol definitely did _something_ in terms of sharpness, but it also really made the blade look good too. I opted out of forcing a patina last night and just oiled the blade with canola oil. It seems the omega-acids in canola does affect the patina slowly over time though. This morning I noticed some new darker areas.

Have a look, decide what you think and then do your research. The Opinel is amazing, cheap, can be sharpened crazy and have a significant role to play if you care for it. I am planning a resharpening and rehoning of the blade this weekend, followed by a forced patina. If that happens, I will post about it too.

Autosol’d and Canola’d

Edit: Patina applied by apple-cider vinegar (boiling hot, over about 15 mins) was completed. The texture is not uniform, but it is completely covered. Apologies for the oil droplets on the blade here, as it makes the photo harder to decipher.

Did this affect sharpness of the final edge? I think it did, it feels that way.

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