Saturday, March 9, 2013

Penny Stain WIN!!

 It has been said on Pinterest that one can make a caribbean blue stain out of pennies soaked in vinegar for a week.

To the frustration of many pinners, this has experiment has failed over and over again.

But before I knew this, I wanted to take a stab at that oh-so-gorgeous penny stain! I love it when I can experiment with science AND art. It's, like, what my brain was made for or something. Luckily, my brain is also wired to do research before starting such a project (lesson learned from many childhood volcanos gone wrong. *Shudder*). I figured there HAD to be some sort of ratio of vinegar to pennies, estimated time lapse, etc. etc. etc. 

This is when I found out if you throw a handful of pennies in vinegar for a week you get a niiiice big chunk of!!!!.... nothing. So what's the dealy, yo? Luckily I found the answers!

There are two important facts to note if you want to do a penny stain. 

1.  Not all pennies are created equal: 
"In 1962, the cent's tin content, which was quite small, was removed. That made the metal composition of the cent 95 percent copper and 5 percent zinc. The alloy remained 95 percent copper and 5 percent zinc until 1982, when the composition was changed to 97.5 percent zinc and 2.5 percent copper (copper-plated zinc). Cents of both compositions appeared in that year." - US
I also read another blogger who experimented with pennies and vinegar and found that she had most success with pennies from the 1960's. So maybe it is the tin from pennies before 1962 that contributed to the deep blue? Not sure on the details yet, but 1960's pennies DO work the best (as you will see later in the blog post).

2. You can't use vinegar alone! 
There must be an introduction of oxygen in order to get any chemical reaction going. This can quickly be done by adding a secret ingredient. Are you ready for it?
Just add even a couple of tablespoons and you are going to get yourself a stain in a matter of hours. This is why no one was having success by just adding pennies to vinegar. 

So I decided to try a little experiment. Since I didn't want to waste time copying other experiments, I just did two jars of pennies mixed with vinegar and hydrogen peroxide.

Here were my results:

I was actually quite shocked at how quickly the chemical reaction happened on my jar full of pennies from the 70's through the 2000's. It literally happened in a matter of minutes. However, the 60's took a couple of hours to start looking blue. It did, however, start to turn blue on the first day.

Yet oddly while the 60's penny stain stayed blue, the other elixir did not. The 60's got more and more blue, and the 70's through 2000's color practically diminished by day 3. It was completely gone by day 5. I was actually quite bummed because I was excited to see what sort of colors each stain produced. They were so different! I wonder if I had only used pennies before 1982 (when they changed to mostly zinc) it would have stayed that cool, mossy green color (hey, YOU should give that one a shot!)

But as it was, my 1960 penny stain won out, and that was what I used on my wooden sign. 

I had enough stain from about 6 oz of vinegar and 2 tablespoons of hydrogen peroxide to do 6 coats on 3 wooden letters. It turned into a BEAUTIFUL greenish blue hue. I wasn't ever planning staining all of my letters. I also wanted to try modge podging some beautiful tissue paper I've been saving for months onto one of the letters, and the last letter was saved to pay homage to the source of the stain itself. I literally wanted pennies EVERYWHERE! The tissue paper letter was just an added bonus.

(Side note: I also read that the stain isn't "stable" so it is a smart idea to seal the stain. I just used modge podge over the stained letters as a sealant)

This is how the final product turned out:

AWESOME, RIGHT!?!?!? Wow, I was so surprised at how pretty it turned out. I think I'm going to hang it on my wall over my makeup area. But seriously, imagine how pretty this stain would be on some old wood furniture? Game boards, bird houses, the possibilities are ENDLESS. 

So now you know how to do a REAL penny stain, the right way. Get to it! And send me pictures of the masterpieces you make. I would love to see it all :)

Happy Creating!


  1. Awesome! Question.I plan to do a larger project. Can I reuse the pennies over and over or is it one time deal?

    1. Mr Clark,
      To answer your question, no. But the pennies can still be used for legal tender. I myself am a chemist, and I'll explain why they can't.The reasoning behind why this works is because of the copper reacting to form a beautiful cupric acid with the vinegar and (to supply oxygen to complete the chemical formula) hydrogen peroxide. Once the copper is all reacted with the solution, they are done. A good way to speed up the reaction so you don't have to wait the 5 days, however, is heat and agitation. So if you shake the mixture and heat it (carefully or it will break the jar), it can be done in a few hours. That's what I did. But the pennies are done after the one run, I'm sorry.

  2. Hey E Clark! I don't know 100% for sure on this one. I believe I tried using them again and it didn't work. But I didn't specifically try for the purpose of doing another stain. So I would give it a shot for sure! Please let me know if it works or not :)

  3. Very cool! what is your vinegar to hydrogen peroxide ratio?

    1. Hey Maggie. I actually didn't have a specific ratio, I just poured some in. It didn't take much, maybe a tablespoon. Hope it works for you!

  4. I'm going to try this, starting tomorrow. BUT--I'm not using pennies. I have lots of scrap copper electrical wire from when my husband worked as an electrician. He stripped the insulation of a length of wire for me and I snipped the copper into short little pieces. This is 100% copper, so I'm anxious to see what happens color-wise!! I will report back to you with pix if I can figure out how to get them to you.
    I have a question for you. Do you know if this stain can be used on fabric, too? Hmmmm, another experiment!!

    1. Hello Linda! Did your experiment go well? I'm dying to know!

  5. Thank you so much for posting this!

  6. I am in the process of trying this and although my solution looks just as bright as yours, it isn't actually staining the wood :( and I can't figure it out. Do you really have to wait the whole week even if my solutions is bright blue on day 2?

    1. Hey Duncan! My solution was also very bright on day 2, however I didn't try staining the wood at that point. I started a week later, but my wood didn't stain until I did 3 or 4 coats. You might want to check out your wood as well. Is it sealed already? That might make a difference. Otherwise, I don't know why it wouldn't stain early than later. Any luck?

  7. Hmm, I was also interested in how Linda's experiment came out, as I happened upon this page today...a few short hours after I started my own pure copper "home brew"! Sadly I see no follow-up, so I'll toss my hat in and share. At least shortly we'll get to learn something, and I'll happily update you if you want (or post pics, whatever I'm supposed to do on here).

    My mixture is more or less a 6/1 ratio of ACV / hydrogen peroxide, plus as much copper as I could cram under the liquid level without horribly mangling my hands. Copper is unadulterated from heavy-gauge electrical cable, cleaned of possible residual oils from handling, leftover from my last project. Ironically, that project was REMOVING rust instead of creating it in vinegar!

    Copper / ACV / peroxide combo has been sitting in a dark cabinet (so as not to mess up the peroxide) for several hours now, and I'm dyin' to take a peek!

    1. Robodie, I'm wondering how it turned out! Such a wonderful experiment every time it looks like to me. If no one responds with results, I guess each of us has to try it ourselves. Bummer! Life's busy for all though, so it's understandable.

  8. Hi, I wanted to update with my findings. I used the recipe posted above to get started but I made some tweaks.

    #1 -- I used copper tube. Pennies were removed from our currency (Canada) so it just wasn't an option for me plus all that sorting was unappealing. I image copper wire would work well too but you would need quite a lot of it. The important part is the copper, not where you get it.

    #2 -- I started with a small amount of hydrogen peroxide but after a week I added more. My guess is this: as it reacts, you're not running out of copper or vinegar; you are running out of the oxygen needed to create this lovely, toxic hue. If you want to make it stronger, you need more of the peroxide. Adding just a splash more peroxide turned mine from turquoise to BLUE. Adding more copper isn't going to do anything if it can't react with the other elements.

    I had tested my finish using a bit of baltic birch plywood and after 4 coats I only got a pale wash. Having added peroxide, a test coat was instantly more vibrant and the hue hasn't changed (still turquoise even though the liquid is now a strong blue). Basically, I will need less coats to complete my project.

    I'm not sure if I can get notifications from this so I will check back periodically. If you want to see some photos and updates, I have posted some on my instagram account: @magininka

    I am happy to answer questions from there but please state that you found me on this post.