Carbon Opinel with patina rusting ...

[lonestar1979]

I started carrying carbon no6 for edc and this morning was in shorts pocket,i was sweating when walking for couple hours.When i got back ,tried to cud sone sausage for breakfast and noticed some rust starting to form on edge and sides of blade .This opinel had patina but still picked up rust in couple of hours.I am deffinitely switching to stainless no6that i got the other day.I never had problen with stainless one even when cutting various fruits and not even wiping it off.Any experiences are welcome.Should i make different patina?Any advice besides oiling it up?

 

[Bob6794]

Heard of someone using chapstick on the blade with success on the traditional forum. Sounded like too much work for me to coat the blade after every use.

Knife sheaths work in my experience so your not sweating on it. I have a knife in 01 I love the design of but I dislike the steel for how easy it rusts.

Beyond that oil it up, or just use stainless too make your life easier.

 

[SteelJunkee]

Try hot paraffin instead of oil.

 

[lonestar1979]

Ill carry stainless Opinels in pocket,always liked them better,besides thickness of blade.Victorinox saks that i use the most have one big advantage with blades and all tools,no rust.In humid and wet climates its a big advantage

 

[FortyTwoBlades]

Just take some fine steel wool and remove the rust and carry on. A forced patina may help with rust prevention, but it doesn't totally eliminate it, and I find that an earned patina generally is more neutral and rust resistant than one that's been forced. I have a No.8 that's often been in humid environments and simply because it's thoroughly used and "broken in" it doesn't have any issues with rusting or swelling shut in humid weather.

 

[lonestar1979]

I noticed that too that forced patina rusts but natural one I almost never had problems with

 

[SteelJunkee]

Just take some fine steel wool and remove the rust and carry on. A forced patina may help with rust prevention, but it doesn't totally eliminate it, and I find that an earned patina generally is more neutral and rust resistant than one that's been forced. I have a No.8 that's often been in humid environments and simply because it's thoroughly used and "broken in" it doesn't have any issues with rusting or swelling shut in humid weather.

I noticed that too that forced patina rusts but natural one I almost never had problems with

It makes a whole lotta sense, different oxidants produce different oxides, making a more heterogeneous patina.

 

[lonestar1979]

Ill let it develop natural patina,like the thinness of carbon opinels and how they slice but overall stainless ones are better,with edge holding too.Ill lover the angle on my stainless ones and then give it secondary edge,thats almost invisible or strop it on strop with green compound.That should equalize cutting efficiency,my stainless opinels have visible secondary freehand edge at 30incl and secondary of 40 and still slice well but will do convex at lover angle How they cut now is good too but this convexing to almost zero will make it straight razor sharp.

 

[drail]

You need to understand that "patina" is not a protective coating against rust. It is itself a form of rust. Just like bluing or browning on a gun is a form of rust and offers almost no protection from further rusting. Only if you seal the steel off from any contact with oxygen by coating it with paint, oil, grease, wax or some type of non ferric plating can you stop corrosion. Just keep it dry and clean it off when you see it. It's just a compromise you have to deal with when you live on a planet with an oxygen rich atmosphere but most of your tools are made of iron rich alloys. The reason steel and cast iron rust when exposed to water is because water contains oxygen. Probably the worst thing you can expose a piece of steel to is salt. Just ask the U.S. Navy. Salt will eat holes through steel very quickly. Even if the steel is already covered in iron oxide (rust).

 

[FortyTwoBlades]

Patina does protect a blade from rust as compared to bare steel. It's a comparatively stable form of oxidation that creates a layer of oxide on the surface of the metal, shielding it from interacting further with oxygen in the atmosphere. That's literally how stainless steel works, except the oxide layer is from chromium oxide rather than iron oxide. Stable iron oxide coating in the form of a well-developed patina has a significant preservation effect on carbon steel, but it's still able to rust if exposed to humid or corrosive environments/substances for long enough. It's just much slower to start rusting than it would be if it were bare exposed steel.

 

[drail]

Thank you.

 

[lonestar1979]

Ill stick to stainless for most part,and leave carbon opinels at home.I noticed carbon ones lose edge fast when cutting acidic fruits and vegetables.They keep cutting but the edge is not crisp and toothy like that of 12c27 after few minutes of cutting.I thinned down no10 in stainless and its zero edge with small almost invisible secondary.Its cutting better than carbon ones,and it has that toothy bite that carbon opinel seems to lose really fast when cutting acidic fruits.

 

[RipD]

The reason steel and cast iron rust when exposed to water is because water contains oxygen. Probably the worst thing you can expose a piece of steel to is salt. Just ask the U.S. Navy. Salt will eat holes through steel very quickly. Even if the steel is already covered in iron oxide (rust).

It's a little more complicated. Air is equally important. For rust created when steel is exposed to air it's more because water is a an electrolyte. When water hits steel in the presence of air it forms a weak acid. As the acid dissolves some metal the O2 from the water bonds with the metal to form iron oxide. The reason salt water causes more rust is that it's an even better electrolyte. Different process takes place for rust to form under water since there is no air.