Fuuunky Patina

[Omega Leather Works]

So I decided to dye my Sodbuster green. I *think* that the handle material is Delrin, but I've never had Delrin resist a dye job so tenaciously before.

Anyway, if you didn't already know, the handle on a Case Sodbuster is permanently attached. My usual mix of dye includes vinegar and being that the blade is carbon steel I knew that it would patina.

Before the bath I cleaned the Delrin really well, but didn't give thought to cleaning the blade.

This is what it came out looking like.

Not only are my finger prints etched onto the blade, they're green, and they won't come off.

I'm calling this the "Biometric Patina"

 

[Obsessed with Edges]

I've heard that the copper in brass alloy can 'leech' (no, 'leach') into adjacent materials, when exposed to acidic conditions. This is what causes so-called 'verdigris' staining (green oxide or whatever it is) on knives stored too long in leather sheaths (acids used in tanning are the culprit). Being that your fingerprints are etched in green, it makes me wonder if some of that has taken place.

At any rate, if you want to remove them, some wet/dry sandpaper will take care of it, I'm sure.


David

 

[mtangent]

I would leave it like that.

 

[pertinux]

I wouldn't leave that knife at the crime scene.

You know, after you do your crimes?



~ P.

 

[Magnaminous_G]

I like it! I think that looks really good like that.

 

[Omega Leather Works]

I've heard that the copper in brass alloy can 'leech' into adjacent materials, when exposed to acidic conditions. This is what causes so-called 'verdigris' staining (green oxide or whatever it is) on knives stored too long in leather sheaths (acids used in tanning are the culprit). Being that your fingerprints are etched in green, it makes me wonder if some of that has taken place.

At any rate, if you want to remove them, some wet/dry sandpaper will take care of it, I'm sure.


David

Well the pivot, or pivot caps or whatever those are appear to be brass. Wonder if they played a part...
Good one P. Thankfully I'm a perfect little angel so no worries there!

Yeah I'm leaving them. They actually look really cool in person.

 

[Omega Leather Works]

Oh the liners too... Wait, is that what you're saying? I'm lost.

 

[mtangent]

Leeching would be the wrong term.
Galvanic exchange is probably more correct.

In an acidic solution, metal ions from all the reactive metals are dissolved into solution.
If the item is left in the solution, & the solution not flushed or renewed, the acidity decreases, an equilibrium is reached, & the metal ions start depositing out of solution. But they don't go back where they came from.
In this example, copper is the least reactive metal out off iron, zinc & copper, so it will be thee first to start depositing out of solution.

That's my explanation.

 

[Obsessed with Edges]

Well the pivot, or pivot caps or whatever those are appear to be brass. Wonder if they played a part...
Good one P. Thankfully I'm a perfect little angel so no worries there!

Yeah I'm leaving them. They actually look really cool in person.

The brass liners & pins may be contributing also. In fact, on traditional knives, verdigris is often found around the brass pins attaching the covers to the scales (liners).


David

 

[Obsessed with Edges]

Leeching would be the wrong term.
Galvanic exchange is probably more correct.

In an acidic solution, metal ions from all the reactive metals are dissolved into solution.
If the item is left in the solution, & the solution not flushed or renewed, the acidity decreases, an equilibrium is reached, & the metal ions start depositing out of solution. But they don't go back where they came from.
In this example, copper is the least reactive metal out off iron, zinc & copper, so it will be thee first to start depositing out of solution.

That's my explanation.

That's likely more accurate, thanks for that.

I think 'leaching' was the term I would've intended to use, in a very generic sense only. Different spelling & definition than what I posted above, and defined to describe how something tends to move/migrate/percolate through another material (often in liquid solution), and ending up in places where it wasn't intended to be.


David

 

[mtangent]

That's likely more accurate, thanks for that.

I think 'leaching' was the term I would've intended to use, in a very generic sense only. Different spelling & definition than what I posted above, and defined to describe how something tends to move/migrate/percolate through another material (often in liquid solution), and ending up in places where it wasn't intended to be.


David

That's funny, I hadn't even noticed the spelling!
I thought you were referring to copper leaching through the steel, rather than travelling through a solution.

 

[Obsessed with Edges]

That's funny, I hadn't even noticed the spelling!
I thought you were referring to copper leaching through the steel, rather than travelling through a solution.

I hadn't even considered the possibility of a secondary spelling & definition, until you described the chemistry. I always tend to be somewhat paranoid about my spelling anyway, so I looked it up and found the more appropriately defined example of what I was attempting to describe.

I still think your description of the chemistry is the more accurate picture of what's probably going on here anyway. :thumbup:


David

 

[Omega Leather Works]

Haha you guys kinda went over my head a while back. I can tell when that happens because I get a "10 mile stare" into the screen. That use to happen with the sharpening threads, but I hung in there. I'm not about to get wrapped up in chemistry lessons though!

All I know is the blade is purdy.