Will CPM 3V Patina?

[Uncle Buckmaster]

I'm aware the due to the fact that it's a Powdered Tool Steel with a relatively high Chromium content that it won't patina as readily as a traditional Carbon Steel from ordinary use, but since it isn't a Stainless Steel it still has the potential to develop a patina, even if it might have to be applied a bit more deliberately.

Does anyone here have any knowledge/experience on the subject? I ask because I've been looking at some knives with 3V blades lately and I'm fond of the look of knives with a patina, so I'm wondering if 3V might develop one with use, or at least can be made to develop one otherwise.

 

[shinyedges]

It won't patina like simple carbon steels. Or at all actually. It will rust if neglected for a long time.

 

[Alberta Ed]

Sort of, like M4, another tool steel. But so what? A patina doesn't weaken or contaminate the steel. I appreciate the patina on my high carbon steel knives as they remind me of great hunting trips.

 

[shinyedges]

Sort of, like M4, another tool steel. But so what? A patina doesn't weaken or contaminate the steel. I appreciate the patina on my high carbon steel knives as they remind me of great hunting trips.

3v is WAY more corrosion resistant than m4. Not even in the same boat.

 

[91bravo]

Yeah, I’ve had 3V blades for years now and no discernible patina that I can see. M4 will stain instantly after cutting something acidic.

 

[353]

Nope, I've had stainless steels like ZDP-189 rust more easy. And never a patina.

 

[Uncle Buckmaster]

Darn, I thought so... Thanks.

 

[jux t]

Here’s a very zoomed in/low quality photo of 2 CPM-3V Master Hunters. Top one has a forced patina.

 

[91bravo]

D3V after 6 years of use. Some veggie slicing in the beginning, but mainly sees wood. No staining whatsoever.

 

[shinyedges]

Yeah, I’ve had 3V blades for years now and no discernible patina that I can see. M4 will stain instantly after cutting something acidic.

I've had the same experience with m4 and the same experience with 3v.

 

[91bravo]

I've had the same experience with m4 and the same experience with 3v.

Worse than M4 would be K390. That steel stains just looking at it wrong lol

 

[Uncle Buckmaster]

Here’s a very zoomed in/low quality photo of 2 CPM-3V Master Hunters. Top one has a forced patina. View attachment 2421436

What method was employed in order to yield such results?

 

[jux t]

What method was employed in order to yield such results?

I’m not actually sure. I bought it with the patina for about $60, it’s a spare I often carried on a pack when I lived in Oregon. Got wet all the time and never got darker. It looks like the previous owner sanded the stonewash away and dipped it in something very acidic. Here’s a better picture:

 

[shinyedges]

I’m not actually sure. I bought it with the patina for about $60, it’s a spare I often carried on a pack when I lived in Oregon. Got wet all the time and never got darker. It looks like the previous owner sanded the stonewash away and dipped it in something very acidic. Here’s a better picture:
View attachment 2421516

I've blackened infi with a powerful etching solution. Still have it actually. I wouldn't consider using an acid of that strength "patina".

 

[Richard338]

I've blackened infi with a powerful etching solution. Still have it actually. I wouldn't consider using an acid of that strength "patina".

Yes, you can darken and even blacken 3V using repeated cycles of ferric chloride etch. This sgian dubh was blacked and then polished again to leave some contrast in the file work. I wouldn't really call that patina either, but I suppose you could do a few cycles and leave it greyish.