Tuesday, September 25, 2012

Penny Stain

My first semester of college I watched a friend once take all the pennies out of his wallet and throw them away (we were at a fast food place...so I wasn't about to dive after them). It seemed so odd to me to throw money away...even if it was just a few cents. Right then I started collecting any pennies I found. I picked them up off the street, gathered them from under the cushions and saved my change. I was going to see how long it took for the pennies to add up. Well, it was slow but over time I had over $20 in pennies. Not too shabby. After graduating I didn't keep up with my "project" as heartily, but I still had most of my penny stash. But...I didn't ever know what to do with it (I'm a scrooge with my hard sought pennies and don't want to pay the fee to have the machine sort them so I can have my few bucks). Lately on Pinterest I've seen quite a few different penny projects, but I hadn't ever done one until we received a project that needed testing. 

The Original Pin
natural wood stains
(No...that isn't what this stain actually looks like...but that is the only picture on that page so that is the picture that gets pinned all over Pinterest. I haven't found a picture of penny stained wood). You can make a wood stain by putting pennies in vinegar! The site says, "Vinegar works as a wood stain when you add a metal object in the mix and let it sit in a glass container for a week.  A handful of pennies will produce a beautiful pale Caribbean blue stain." Allison tried it out and sent it to us. 

The Pinstrosity

Not the Caribbean Blue she was expecting. Here's what she did:

"Day 1: Placed a "handful" of pennies in a jar with vinegar. 
Days 2-6: Every time I walked by and thought of it, I would just shake the jar a little.  The instructions don't say to do this, but I thought, "What could it hurt, right?!?"
Day 7: Opened the jar (very difficult to open by the way--I don't know why, but it was really bad!) and proceeded to use a foam craft brush to give the 2x4 I used a good coat of the stuff.  After that dried, I coated it again, and again, and again (5 times in all.)  As you can see from my picture, 5 coats did a little something, but not much at all.  Not enough to make me get the "Hey! That wood looks kind of like barn wood!" feel and it definitely wasn't worth my time to put 5 COATS for that result."
"I'm not sure there is much hope for this project.  Upon further examination of the vinegar on day 7, I realized that most of the apparent darkness was actually just an illusion.  Little floaties from the pennies were actually most of what made my "stain" (if you can call it that) look darker.  I want to try using a different type of metal (like steel wool) and see if that has a better result.  There just wasn't enough of a chemical reaction between the copper and the vinegar to give a nice stain to the wood."

So it was a disappointing bust of a project for Allison, but it got me quite intrigued and I wanted to test this one out a little bit further. Out came the remains of the penny stash. 
Found that penny jar at a thrift shop when I was in high school and had to have it.  

I dumped out my pennies...take a guess at how many are in that pile.
1962 pennies! Did you guess anywhere close? 

I decided that I wanted to test this one out pretty thoroughly, so I got "scientific" with it. I sorted the whole penny pile out in decades and then counted how many pennies were in each decade pile (for those interested, 2010-present: 62, 2000's: 842, 1990's: 491, 1980's 322, 1970's: 176, 1960's: 62, 1950's: 2, 1942: 1 1919: 1, unidentifiable: 3).  I wanted to make sure that I had the same penny to vinegar ratio in each container, so I calculated out 1/8 tsp. per penny of vinegar and poured it in jars and then added the pennies. 

The 1990's took two jars because I couldn't find another jar large enough, but the ratios are still right in their separate jars. 

Since pennies had a much higher copper content before 1982, I was curious to see what each individual decade would produce as far as a tint. I left these jars on the counter for 16 days (I know...it said a week, but I extended it) and here's what I got:

Some jars seemed unchanged...some were dirty and nasty and one was tinted blue. 

Mostly unchanged. 

Mostly unchanged. 

Dirty and nasty!

Clear until shaken up...then dirty.

Unchanged vinegar, but pretty and clean pennies.  

Caribbean Blue!

I figured the 70's pennies were going to give me the best tint...but there wasn't any tint at all! 
The pennies from the 80's and 90's fared the worst...they were nasty and had a weird film on them and they just weren't pretty at all. 

So I got to work to see how the stain worked. I had a cute little unfinished wood bird house that I got in the craft section at Walmart. I don't know what kind of wood it is...the label didn't say. Cheap wood...from the cheap tree. Here's the progress:

(click to enlarge photo)

By the end of the 8th coat the stain was quite pretty. It didn't take too long to dry between coats either. 

So there you go...the penny stain does work, but you need older pennies. Just a "normal" handful isn't quite going to do the job for you. And you will have to do multiple coats (but that's pretty normal for a stain...this isn't paint you know). 

Want to see how I finished the bird house? 

I painted the trim copper and then super-glued pennies to the roof as shingles. This'll make a cute addition to our bird bedroom decor. 

Now I need to go find a pin on "How to get super glue off your fingers."


  1. Way to get all scientific!! I wonder what it is about 1960's & earlier pennies. Very cool!

  2. I use vinegar and rusty nails to make stain or "age" wood... pennies... it's a great way to clean your pennies, but won't work.

    1. It did actually work, as shown in the pictures above. You just have to have old enough pennies.

    2. adding hydrogen peroxide to the vinegar will give you the blue you're looking for regardless of the age of the pennies. Saves a LOT of sorting too!

  3. Thankss for doing this. I have a wood chair that I was thinking about doing but now I know not to try this for that chair. Way to much effort to try to find pennies that old!

  4. emergency rooms use Vaseline to remove super glue... apparently it is a super glue solvent, though i've never tried it myself

  5. This was really an interesting post! Thanks for going to all of that trouble and I love your birdhouse!

  6. Acetone nail polish works to get superglue off. I have had to use it a few times:)

  7. Talk about a science project! Thanks for doing the research!

  8. I love how you got all scientific on this one. The final birdhouse result is very cute!

  9. the reason pennies from the 60's and earlier work is because they are actually made with real copper, which was very cheap then. Newer pennies wont work because they are not made with copper any more.
    I learned this while I was a florist.. I love fresh tulips in the spring but they always fall over after a day or two.. well take 4-5 OLD (like 60's or earlier) pennies and put them in the vase.. Your tulips will last much longer, I usually have mine for 2weeks, if not 3. Putting an ice cube in when you change the water will help as well.
    Love the look of the birdhouse at the end!

  10. Since 1982, pennies have been made of 97.5% zinc. Not much copppery goodness there. But the '70s coins should have given the same results as the 60's ones--wonder why not.

  11. Oh, I did this as a science experiment with my kids! This works with older pennies because they are actually made of copper. When they are in vinegar (which is an acid), it produces a compound called malachite which is a copper carbonite (that "caribbean blue" color). it is formed from wet copper reacting with oxygen. So there you go! :)

    here was our penny experiment: http://blog.anportraits.com/2012/03/01/pennies-in-vinegar-seattle-area-lifestyle-photographer/

  12. Ok. This is brilliant and I admire your thorough approach. The penny shingles are just perfect!

    Superglue? Acetone nail varnish remover?

  13. Jewelers use a warmed acid solution to clean the metal after soldering. Heating sterling silver brings copper to the surface and quickly turns it to copper oxide. The copper oxide dissolves in the acid solution, and the solution eventually turns blue.

    I'm guessing that the '70's pennies didn't work as well because they didn't have as much copper oxide on their surfaces, being 10 years newer than the 1960's ones. You could try this: dip them in a vinegar solution, and then lay them out wet to react with the air & get that verdigris patina on them. Then soak them in vinegar until they are clean again, take them out, let them turn teal again, and then soak them again in the same jar you did before. You can do this until you reach a saturated solution - you'll be able to tell because it'll stop being able to clean the pennies. I wonder how dark you can get the blue to be?

    Oh, and if you have a small crock pot you don't want to use for food again, you could use that instead of the jar. Turn it on low, and the heat will speed up the reaction and shouldn't affect the results (jewelers heat their acid). You don't need to leave them in for days, just until they are clean and shiny again.

  14. For the record, STEEL WOOL, soaked in vinegar will create a wood stain that mimics "old wood," with a grey-ish brown color to it. Successfully did this with a coffee table my husband made me. However, the actual vinegar didn't really turn a color, it looks basically clear until you put it on the wood and it dries.

  15. Your birdhouse roof reminded me of this project:

    Jen is very real about the work that goes into her projects! Maybe you could start saving again?

    I actually really like that blue color you got!

  16. Applause for the scientific approach! You remind me of Mythbusters here. They see a project, it likely fails, then they retool it scientifically to truly prove/disprove it. An excellent read. Thanks!

  17. I imagine this would probably work with a few pieces of copper plumbing parts from Lowe's, Home Depot, etc. since those are actually copper, unlike new-ish pennies.

  18. Honestly, just buying teal craft paint and watering it down sounds a heckuvalot easier to me! Also, your trick works with hydrangea plants. A couple old pennies in the soil, or old real iron nails. The pennies turn them that beautiful blue color, and the nails will turn them rusty red. But again, you need to use the old ones because the new ones aren't the same metal. We bought white hydrangeas and planted them only to have them bloom orangey the next year... Had no idea we were planting them in the graveyard of an old farmhouse. (:

  19. http://www.toolgirl.com/toolgirl/2010/03/staining-wood-with-cheap-natural-and-nontoxic-tea.html has a picture of the penny/vinegar stain, and used on wood. not much more information on how to get the stain color, though.

  20. Some dyers use this, or similar solutions of copper, for either dyes or mordant. Except we're lazy, and don't go looking for pennies of the right age... we use bits of copper pipe from the hardware store. 2 feet of pipe is reasonably affordable... and given that a couple of inches at a time is all you need for a gallon of solution, it's pretty affordable. But be careful - copper can be toxic, and many localities request that you dispose of it as carefully as you would other household hazardous waste like batteries, cleanser, and old paint.

  21. If you are dying to try this - copper piping works as well as old pennies, if not better. But beware - copper solutions are somewhat toxic, and should be disposed of in a manner consistent with other household hazardous waste, such as cleansers, batteries, and old paint.

  22. Newer pennies are more zinc than copper, which could create a grayish tint if left long enough. I used copper wiring from inside speakers and such that my son is collecting in his metal recycling bucket. Yeah, the copper is worth more than the rest, but I only needed a little bit, so he didn't mind. Worked great - had a nice light blue hue to it which was all I wanted for my project.

  23. Now this is some investigative journalism! Very cool - you obviously put a lot of work into this. Thanks for all the work because I'd really like to try this and had seen some pretty disappointing results elsewhere.

  24. Wondering if any one can help lift this stain from a wooden panel. I am restoring a pond boat and cleaned all of the copper fittings not thinking about the reaction between the 2 agents. Any advice would be appreciatee

  25. I recently was in a pinch to finish some homemade pallet patio furniture. To stain my unfinished wood, I used half a cup of blue Windex cleaner with half a cup of hot water with about 10 drops of household kitchen blue food coloring. Worked beautifully after brushing/sponging on several coats. More coats = darker shades of blue.
    Inexpensive & colorful.
    * also used brewed coffee to stain alternate colors on my wooden slats; ur only limited by ur imagination.


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