Copper is a great pure metal, you can do so much with it! It will tarnish though if left in its natural state. It might even grow patina, if you leave it in a moist environment with high humidity. Hey, it turned green like the Statue of Liberty! These are also some of the most wished for qualities about copper. People have tried (and succeeded) over centuries to create various natural patinas and surface effects to make beautiful things with the metal.
These copper cleaning methods are for copper that has not been coated with anything permanent, we are talking just regular oxidation and tarnish over pure copper. If you have a piece of jewelry it might have a type of a “clear coat” on it that was applied to preserve the surface (for example, your piece has patina, or was flame painted or just coated to preserve the natural tone of copper). If this is the case the clear coat needs to be removed first. Often, it can be taken off just by regular sand paper, or sometimes a solvent is needed.
One note about any of these methods, they work great but keep in mind to use some common sense. If you have major grease or other sticky substance on your copper, you need to get those off first. We are talking about cleaning a relatively non greasy piece of metal, if you have a piece of copper you found in the garage under several layers of rubble from 40 years ago…you will probably need something stronger for that!
Vinegar is a natural pickle. In jewelry making the word pickle means it removes oxidation and other impurities from the surface of the metal. Just soaking your copper piece in vinegar will pretty quickly bring it back to the original pure copper color. If you heat your pickle, the effects are faster. Now, of course, you can also create patina on copper using vinegar and salt, which is a different end result, but isn’t it fun how you can use this household staple to do various things?
Use a diluted strength for copper cleaning (dilute with water), you might want to start with half water and half vinegar. When happy with results rinse and dry. To bring the shine back you could now use various buffing methods, such as a buffing wheel, steel wool, or high grade sandpaper.
Another good way to clean copper naturally is lemon juice. It doesn’t get more natural than that, you could even squeeze a lemon on your copper! It will take a little longer, but your copper will get clean. To get even results submerge your copper piece in lemon juice and let it sit for about half an hour or longer. (Check on the progress) And, if you want to make the process faster, adding salt or baking soda to the lemon juice and rubbing it on the copper is a way to make it work quicker. And, of course, rinse and dry your piece.
Ketchup – yes, isn’t that odd? Tomatoes are very acidic (had pizza recently and got some acid reflux?) The fun red paste will also work on copper, just leave it on for a while and then rinse.
Common Household Cleaners for Copper
Many of us use some common cleaners around the house, such as Bon Ami or Barkeeper’s Friend. Yes, this is not the most natural method, but if you have them around why not try it. They will also clean your copper! Just make sure your copper is wet, then you rub the stuff on and let it sit for a while. You can repeat this until you get the piece of copper clean enough and then just rinse. (Baking soda is the most similar natural product. It is not quite as powerful, but if you just rub pure baking soda on your copper and rinse, it will also take off most stains and light oxidation.)
With any of the liquids or pastes, remember to rinse them off after you have the desired result. Otherwise they keep on working on the copper and may actually create patina! And dry your piece, moisture will also create changes over time.
Sandpaper or Steel wool
This may sound counter intuitive, but using sandpaper or steel wool is also “cleaning”. Depending on how deeply your copper is tarnished you might choose sand paper, or, if it’s just a minor surface oxidation, use steel wool. Yes, you use sandpaper or various buffers to polish and remove scratches from copper surface when you are making it into something like jewelry. But you can also just remove tarnish. And this also works if you want to remove a simple clear coat. There are spray or more durable coatings that may have been applied to the copper to preserve the coloring, patina, or flame painting. You can always sand any of them off, it might take a bit of elbow grease…but you can always get back to pure copper. Pick a light to medium coarseness (for example, maybe 400-600 grit), if you use a very heavy duty sandpaper you will create lots of scratches in your copper. Let’s say your copper cuff ended up tarnishing, it might have taken a long time, but now you want it back to the original. You can always send it back to your jeweler, have them sand the coating off and start over. It’s like making a new piece all over again!
The great thing about copper is that is a completely pure metal (chemical element Cu) and can take an endless amount of reworking (If you hammer copper it will harden and will need to be annealed, but that is another topic!). Copper is one of the few metals that occur in nature in directly usable metallic form (native metals) as opposed to needing extraction from an ore. You can sand, buff and clean it over and over with no issues. It is not expensive, and so a wonderful metal for experimentation. So, go buff!