Make Silver Different Colors by Anodizing

Make Silver Different Colors by Anodizing


Greetings fellow nerds! In this video we’re going to use electrochemistry to add brilliant color to this otherwise bland and colorless silver bar without using any paint. This process is called anodizing. First, we need to make the anodizing solution. We start with about half a cup of water and add two tablespoons of sodium hydroxide and one tablespoon of sulfur. Both of these chemicals are easily bought online. Then we stir for about ten minutes, which we’ll timelapse for this video. At the end we get this orange solution of sulfur and sodium hydroxide which is highly corrosive so always wear gloves when working with it. Next we filter the anodizing solution to remove any excess sulfur. You can use a coffee filter for this process. Now we have our anodizing solution ready to color our silver bar. Here is our brand new silver bar. Place the silver bar into the solution. Next you’ll need a battery to generate the anodizing potential. Now connect the positive terminal of the battery to the silver piece and when you’re ready, touch the negative wire to the surface of the solution but NOT to the actual silver piece. As you can see it doesn’t take much time to start adding color to the bar. Ok let me take it out and show you what we have. I’m going to wash it for a better look. As you can see, in just a few seconds we’ve added decades of tarnish to the bar and turned it a brown color with blue highlights. If we keep going, we can continue changing its color. So let’s do that. Looks like we’ve got some sort of green blue color this time. Let me give it a rinse. As you can see, the length of time it takes to anodize determines the color of the silver. Let’s go on for a few more seconds and see what happens. I move the negative wire around the bar to give it an even coat. Otherwise the part closest to the wire will anodize faster than the rest. Looks like we got some kind of dull grey color now. Ok another round. I’m not certain how to describe this one, a blue purple color? Ok once we get to this matte black color further anodizing will no longer give us a color change. Now I said before I needed to move the wires because the part closest to the wires will anodize faster than the rest. So what happens if I don’t move them? Let’s find out with this new silver bar. As you can see we’ve gotten this rainbow effect as the parts closest to the wire change color more than the farthest parts. Pretty cool eh? Thanks for watching another NurdRage original video.

100 Comments

  1. Always interesting to discover how US silver coins are wrecked by creating these ridiculous colours and then the grading companies are only too happy to grade this garbage.

    Fortunately, in the UK we are more interested in the authenticity of the coin not its bizarre colours, though some of our idiot eBay sellers polish the coins that they offer for sale!

  2. Quite right. serious collectors do not like coins turned into dreck and not stupid faked colours and that is why you find thousands of this garbage on US eBay but hardly any on the UK site, despite your rather silly reply.

  3. I have a question, is there a way to incorporate a resist in this? I want to make part of the bar black but only in certain places.

  4. Could you make one on aluminum? I wish i could make that efect on aluminum 🙁 (like soda cans)

  5. Is the color permanent, can it be made silver again if you don't get the desired effect?

    I love the look of the second bar, it would make a nice pendant!

  6. What solution could I use to get a "rainbow effect" where the most tarnished effect would be bluish/purple and the lowest tarnish would be yellow/gold with red inbetween?

  7. Your Polarity is Charging the silver and going into the anodizing solution….Should you have your giving positive polarity in solution and negative receiving pole touching the silver bar………?  Or does it even matter……..?

  8. You are supposed to change the voltage to control the thickness of the oxidation layer, so that it results in different colors, that way the layer/color is more consistent. Using a higher voltage and control time is harder to control and not as consistent. This is just like any other non-ferrous metal's oxidation, except the voltage-color relation is not well documented. If you google titanium, for example, the voltage-color relation is well researched and documented.

  9. Can anyone tell me if this process would work on a mirrored? The backing paint will be stripped off the mirror & what I believe is a silver coating would be exposed. any help would be much appreciated

  10. Thanks for sharing this video. I would like to know if this anodized layer is durable. Can I use this process in a silver ring, for example?

  11. I have an electroplating machine for plating precious metals and a power source that allows me to set the ampers and volts to what ever is desirable. What is the best Amp and volt settings? It appears you're recommending 3v but what about amps?

  12. LOVE this method and I cannot wait to try it.
    You mentioned that you've kept your rainbow bars stored for years, and another poster said that their tone turned grey after a few days. Do you neutralize the chemicals on your silver afterward?

  13. NurdRage   If I reduce your recommended NaOH and Sulfur dosage by half, would this help slow down the anodizing process so I can have better control on rate of anodization?  Also, you didn't show the back side, does the back side get similar degree of anodization?

  14. A similar thing happens to my silver ring everytime I wash dishes or take a shower I was looking for an explanation when I found this video. Any ideas?

  15. Hello

    I've tried this, and worked somehow. My solution turned into an orange-ish color, i placed the silver coint (.835) into the solution, but before i could attach the wire to the coin, it started to oxidize itself. The result is not a rainbow patina, but it has a darker color with some green-purple color.
    Was the solution too "strong"? I user 1 tablespoon of sulfur, and 2 sodium hydroxide with ~100 ml of water, and i stirred it for 10 minutes. After that i filtered it.

    Thank you in advance.

  16. i am searching for green plating of studded jewellery can any one help me for,how to do green plating of diamond studded jewellery

  17. Could you apply this method to an electroplated object and is there any risk of tetinus after oxidation and wear? Would make for a pretty dope belt buckle.

  18. Nurdrage… do I need a special kind of lab glass for this process? Or will any glass do? For example, can I use a small pyrex dish? Or do I need glass that will resist the electrochemical bath? Thanks for your time and the awesome video!!

  19. WOW! You are great! Could you please give a solution to make rainbow (oil slick / neo chrome) anodizing for steel and titanium, too? That would be amazing! PLEASE!! :))

  20. ive got like 86 ounces of silver im trying to tone lol mostly 10 ounce bars and maybe 15 ounce of smal bars and junk rounds id like to do this with was trying to do it naturally. I just dont think i can wait 20 years lol

Leave a Reply

Your email address will not be published.


*