Forcing a grey patina? Also other patina questions

D

Death132

Joined
Nov 14, 2012
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What is the best way to force a grey/dark grey patina on a Carbon Steel blade?

How long does a patina last for and will it wear away either with use or sitting around?

Will forcing a patina remove the shine from the blade?

I've read about apple cider vinegar and red wine vinegar but need some more opinions. If anyone has used these can you post any pictures?
 
Grapefruit is also a good thing to use. This isn't my knife, but the patina looks about the same as mine.
BK2001_zpscd15b491.jpg
 
All you have to do is soak he blade in vinegar and boom patina iv even seen some people use hot vinegar to speed up the Process.

image.jpg

Good luck!

Oh and this should be in Maintenance tinkering and embellishment.
 
Almost any food acid will do it. I've done it with grapes, pickle juice or vinegar, mostly on a 1095 blade (Schrade 8OT). The results of the pickle juice patina are seen in pics below. I soaked a piece of paper towel in the juice, then wrapped it around the blade. Left it in place for a couple hours, which was longer than really necessary; it produced some significant rust on the blade, which I scrubbed away with baking soda. No deep pitting or other real harm done, but the surface rust produced was a bit of a surprise. :eek: Moral of the story: it doesn't take long, and keep an eye on it.

I've also tinkered with what I call my 'coffee pot patina', using a heated mix of 1 part vinegar to 2 parts water, at about 180°F. I did this spur-of-the-moment, on a whim, after running the vinegar/water mix through the coffee maker to de-calcify it. Just 'dipped' the blade into the pot of hot liquid, held for maybe 30 seconds or so, and repeated 2 or 3 additional times. Blade turned nearly black in doing this. Rinsed the blade in cool water, then scrubbed with baking soda to stop the acidic reaction and remove any red rust that might be created in the process. The baking soda cleanup will remove a lot of the really dark/black oxide, leaving a nice grey behind. Then rinse it thoroughly again. This is a pretty good way to make the patina more even, and the color is very similar to the pics above, but with less spotting/patterning on the blade.


David
 
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I use straight lemon juice, a bit more acidic than a 5% vinegar. Time varies w/ chromium tho-- 2 hours on M4 won't be as dark as blades pictured.
 
Is ferric chloride acid another good choice? Just put an even coat on the blade later rinse it off?
 
Ferric chloride is excellent if you are looking for an even patina, it is what it used by most custom makers to bring out the pattern on Damascus and hamons. It's available at radio shack for about $12. Dilute the radio shack mix by 50% water. Clean the blade extremely well, any oil will "smudge" the patina. Acetone and or break cleaner work wellfor removing any oil residue from the blade. Acetone will leave a residue but this does not affect a FC etch very much.

DO NOT TOUCH after cleaning. Suspend the blade directly in the ferric chloride, do not let it touch the side or bottom of the container. Pull it out after a minute and check the color. Return it if you want a darker shade...

Do not let any brass or copper come into contact with the ferric chloride. These materials will dissolve into the acid and then coat the steel through an electrical process, you get a battery with copper and iron in acid.

In fact, you can get an interesting copper patina if you pollute ferric chloride with copper and then etch a steel blade in the polluted FC. This copper plate is less durable than a straight patina however...

There was a photo of a beautiful copper shaded steel blade a few weeks ago in the knife makers Q&A forum. Sorry, could not locate the thread.
 
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