Patina: The Process

[ArfinGreebly]

With my "redundant" Case 3138CV sodbuster safely arrived, it's time to prepare the primary unit for use.

I thought it might be interesting to do a photo spread of the process. Below are selected shots. The full spread is here: http://www.noisyroom.net/pix/thr/2008_0401-Knife/Smaller/

Cauldron of seething acids
Actually, a mug filled with a) a half/half mixture apple & grape juices, up to the halfway mark, and b) Jasmine tea (normally Earl Grey, but I'm just using what's in the pot). So, half juice mix, half tea.
Microwaved for a minute and a half, to about 150 degrees.



The ground/sharpened part of the blade submerged.
Notice the little bubbles forming on the blade surface.



Lean one way . . .



Lean the other way . . .



After turning a few times, rinse blade and inspect.





Back in the bath . . .



Are we there yet?



Yes, we are. Patina established.







Ahhh, there we go. Satin smooth grey finish.





All done.

​

Followed by stropping the edge and wiping down the blade with cooking oil.

And there you go.

Top to bottom, the process was maybe 20 minutes!

And I didn't even cut myself.

 

[sm]

*applause*

You don't get stuff like this on the AM ra-did-di-o .


This thread needs a soundtrack ...

I can see you, your brown skin shinin' in the sun
You got your hair slicked back and those Wayfarers on, baby - Boys of Summer , Don Henley

 

[rugerfreak]

Didn't realize the Sodbuster was such a stout knife---might have to try one of those myself.

 

[ArfinGreebly]

Stout

Yes, they is certainly stout.

The one above (3138CV) is, far as I know, out of production. It's evil twin, the 2138SS (black handles, stainless blade) is still made.

I snagged the one above and its duplicate from a fellow on eBay. The first one was a steal. The second was more hotly contested, and I paid more than twice what I did for the first one. No tears, though.

Happily, Böker makes a very reasonably priced clone in 1095 (I believe) carbon steel. The darkening process turns the carbon steel blacker than the CV steel, but I have no complaints.

I've got a group sodbuster photo here somewhere . . .

Ahh, here it is

​

The large Böker is right next to the large Case. You can see the darker blade, and darker yellow handles.

 

[daniel (australia)]

Interesting treatment. It may be the photos, but that looks more etched than patinated. Is that what it looks like "in the metal"?

Nice looking knife though

BTW have you ever tried onion juice for a patinated effect?

 

[BigG]

Is it that you object to the shine of the new stainless steel?

 

[hso]

You can use Frenches mustard (or any "yellow mustard") to "age" steel.

BigG,

The CV is a carbon steel blade Case instead of "stainless".

 

[BigG]

Carbon Steel

Oh, in that case it will turn black by itself after a bit of use. Cut some fruit and forget to wash it off. That is a favorite to blacken a Carbon Steel knife in a hurry.

 

[Robert Hairless]

A little Flitz and some rubbing would get those knives shining again.

Before I joined this forum I was old and broken down. Now I am patinated. This distinction is worth money.

 

[eliphalet]

Be interesting to know what a drop of pickle juice left for a bit, or something similar would do to that nice looking "patina" you've done. Would it stain the steel or will your process hold up akin to bluing.
Looks nice Arfin

 

[ArfinGreebly]

Character

. . . looks more etched than patinated.

It's quite smooth to the touch. If you go to the link in the OP, you'll find photos with higher reflectance.

You can use Frenches mustard (or any "yellow mustard") to "age" steel.

That's good to know. I wonder what's in that stuff.

Cut some fruit and forget to wash it off

Yeah, I have a carbon steel Mora knife that I did that with. The staining is uneven, so I'll have to try a mustard bath (or onions or something) to even it out.

A little Flitz and some rubbing would get those knives shining again.

Thanks for warning me. Note to self: don't be cuttin' no Flitz with that knife.


I don't know how this will hold up in use, but I'm going to start using it in the kitchen (veggies, tomatoes, meat, whatever) and see how it holds up.

The Böker was all shiny and unused when I started using it in the kitchen. The darkening was blotchy and uneven, so much so that even after treating the whole blade there are spots that are darker than others.

I have a Case 3137 that I got recently, and it arrived very used. The steel had acquired its patina through simple use and abuse. Genuine aging. It looks . . . somewhat dingy. Of course, with the wear on the handle and general dingage there's no question that it's "just an old knife."

I wanted to give the one above a more even tone as a starting point. If it blotches out over time and use, then so be it. That's called character.

Hey, you can't have too much character.

 

[ArfinGreebly]

"in the metal"

Is that what it looks like "in the metal"?

Sorry, not familiar with that term.

I washed and wiped the blade dry before treatment.

The pictures at the end are after rinsing and before oiling.

Could you explain "in the metal" for me? I'm still learning this stuff.

 

[texascarl]

Good job! Nice fast patina. I've done patinas using different tricks in the past. As mentioed, you can rub the blade with mustard, I wrap in a plastic produce bag/plastic wrap and leave it over night. This produces a nice patina that's 'patterned' all over the blade in the same manner that you smeared on the mustard. I have a large 9" bladed Leuku knife I patina'ed in this manner, and finished by 'thumbprinting' in rows. Sounds odd but it looks good to me. For really large blades, the mustard is a good trick.

Another good trick I've done is take smaller carbon blade and stab it into a potato - usually a potato that's starting to sprout eyes and no longer as good to eat. I leave it overnight. Remove, rinse, stab into another spot and repeat for a few more hours. Repeat until the spud really goes south, then remove, rinse the blade and toss the spud. This repeated immersion in 'tater juice gives the blade a nice multi layered look. Slice up an orange or two, leave it sit a while. Within a few days this looks 'old' to me. I oil the blade at this time, usually this is my favorite patina. I have an old Shrade 'sharpfinger' that has been thru this several times. Almost looks like it's been 'cold blued'

You say potato, I say patina.

 

[CWL]

2 ways I do it.

1st. Use knife to eat a thick steak, I prefer horsradish as a garnish. By the end of the meal, knife blade has that real "blue" patina on it. This is my preferred method!

2nd. I use cold blue like Birchwood Casey. Apply as per directions, then work it over with some 0000 steel wool. Creates instant 'aged' patina. You can reapply different amounts to the blade if you want different levels of depth to show.

 

[Cosmoline]

Very interesting. On a side note, I discovered a mideastern hot sauce that will strip blue better than any commercial product.

 

[Valkman]

I use acid for etching but that's on Damascus stuff. When you're done etching Windex (with ammonia) will stop the etching process.

 

[Skofnung]

I use an olive jar full of hot vinegar to get an even patina like that, and the previously mentioned mustard trick for a more interesting pattern.

I've toyed with the idea of using ferric chloride, but I always chicken out and use a milder acid instead.

 

[MikeJackmin]

I've had good luck using plain white vinegar, heated in the microwave just as you did. I hear Pepsi works, too.

 

[daniel (australia)]

Could you explain "in the metal" for me? I'm still learning this stuff.

Sorry mate. It means "there looking at it directly", as opposed to "here looking at a photo of it": "in the flesh" so to speak, but it isn't flesh.

Photos, especially of things like metal surfaces, are notoriously unreliable as means of jusdging what it'd look like if you were right there. For mine the photographed surface looked like that surface you'd get with a light etch, like one might use in metallography, but it may well look different if I was right there with you, admiring your work in person .

BTW French mustard contains vinegar as the base (as distinct from English, which is based on water). The paste helps the stuff stick in place while the vinegar does its work. As some have said you can produce interesting patterns of patina with it. Fresh onion can do the same thing, and by the looks there's any number of other techniques you could try - you could have a bit of fun experimenting to see which works best.

 

[Kingcreek]

I just cut a lemon or lime, shake off the excess juice and let it air dry.

 

[markk]

White vinegar here also. I usually wrap the blade in a paper towel soaked with it and let it sit a while...

 

[ArfinGreebly]

On Reflection . . .

Y'know, on review, I can see any number of folk reading that first post and wondering what the heck that fruit juice & tea mixture thing is all about.

It's not a magic "patina potion" or anything.

It's a refreshing and relaxing hot drink that I prepare from time to time.

Couple of years ago, I had fixed a pot of tea, and found that I was out of milk/cream as well as honey. Bizarre. I'm never out of both of those. I looked in the fridge to see what was in there . . . and locked onto a juice cocktail that I normally mix for my daughter.

I ordinarily take two half-gallon bottles of apple juice and a half-gallon bottle of grape/cranberry/cherry/mixed-berry or some combination of those, and mix them such that I then have three half-gallon bottles, each containing a two-to-one mix of apple and (whatever) juice. (It helps if you have a handy extra empty half gallon bottle when you start this.) It's tasty, doesn't involve sucrose or high-fructose corn syrup, and it's relatively cheap.

In any case, I filled a mug to about 2/3 with hot tea, and added the juice mix for the remaining 1/3. What I got was an unexpected treat. Best of both worlds.

I've seen (and tried) various "tea blends" (like Arizona and that one with the lizard), but they're always overly sweet and contain "stuff" that I don't think is necessary. This home-brew mix was excellent. Full-flavored and refreshing.

So it became a habit.

When I decided to do a forced patina on my first Case 3137 CV (small sodbuster), I looked around for a good solution. Steve had recommended Coke or Dr Pepper, but I had no sodas of any description at the time.

In the course of brewing up something to drink, it occurred to me that a hot mixture of fruit juices and tea -- such as what I was then drinking -- might be just the ticket.

And there you have it.

It was simply a "field expedient" substitute for corrosive carbonated soft drink.

For those of you who were NOT wondering, no you can't have those five minutes back.

 

[Robert Hairless]

For those of you who were NOT wondering, no you can't have those five minutes back.

Okay, I suppose that's fair. But if I can't get a refund would you apply those five minutes to another post?

 

[starboard]

I wonder about the scope of hydrogen embrittlement

http://corrosion-doctors.org/Forms-HIC/embrittlement.htm

that may occur during acid-based patination or the use of naval jelly. The literature seems to focus on high-stress / cyclical load contexts when addressing failure induced by hydrogen embrittlement, so I'd guess that knives are fairly immune just based on the type of loads they tend to encounter.

Still, I wonder how much hydrogen is produced and enters the matrix (no, Mr. Anderson, not *that* matrix) when you leave the blade in vinegar or Coke or somesuch for a considerable while.

 

[7X57chilmau]

Movement of hydrogen in steel is very slow. There will be no perceptible embrittlement unless you soaked the steel for years in the solution.

J