Copper Cleaning, Placement & Testing
Copper Polish Options
Tarnished copper, as long as it's kept clean, will continue to kill germs. However, darker tarnished copper might not be the look you want. If you like the bright appearance, you'll need to put copper polishing on your chore list.
In our personal training gym, we covered all our dumbbells in copper. After each client finishes using them, they are sprayed with 70% isopropyl alcohol and left to disinfect for 1 minute. We then wipe them down with sanitizing gym wipes. We have a busy facility, so to keep the dumbbells shiny, we have to use copper polish on them about every 3-4 weeks.
We tested four different types of copper polish, and here's what we found.
- Brasso Multi-Purpose Metal Polish for Copper
- Flitz Brass and Copper Tarnish Remover
- Tarn-X Tarnish Remover
- Wright's Copper and Brass Cream Cleaner
Brasso took the longest to apply and produced the least desirable results. Plus, the smell was somewhat overpowering. Brasso was the one polish we could not find a benefit to continue using.
Flitz was the fastest tarnish remover by far. It comes in a spray bottle, and just one squirt would quickly turn a surface from brown to bright. The smell was strong, but not as bad as Brasso.
We had two problems with Flitz. The first was the splatter produced by spraying it. If you put the copper item in a bathtub or shower, you could simply hose down the walls to get rid of the overspray. But when some of that overspray hit a steel rack (and we didn't notice), it started to rust within 24 hours.
That leads us to the second, fairly serious problem we had with Flitz. Once you spray a surface, all copper cleaners instruct you to wash it off with water and polish it with a dry rag. If any of the other copper cleaners were left behind, it wasn't that big of a deal. If Flitz was left behind, it would tarnish and cause a green patina to appear within 24 hours.
The picture below shows drops of Tarn-X, Wright's and Flitz on a piece of 99% copper after 48 hours. You'll notice the Flitz has turned the copper green. The other two brands stayed on the surface, but they didn't tarnish it. Even after rinsing weights under a shower for 60 seconds each, many would still develop a green patina around the edges within a couple of days.
Tarn-X was a good cleaner. You pour a little bit on a rag and then wipe the surface. The smell was similar to Flitz, strong but not overpowering. It cleaned fairly rapidly and rinsed off well. The biggest problem we found was that the shine it produced, even with a lot of buffing, was only average.
Wright's is our favorite cleaner for three important reasons. The first is that Wright's has the mildest smell of all the cleaners we tested.
Second, when you open the container, it's a paste instead of a liquid. It comes with a sponge to put it on. You rub the paste into the copper and let it sit for about 60 seconds. Then wash it off with water, dry and buff the surface with a rag. The paste and sponge make it easy to apply, exactly where you want it, without drips or spray hitting other surfaces.
Third, when we inspected the cleaned surfaces 3 and 7 days later, the ones cleaned with Wright's had the least discoloration and kept the most shine. There were no green patina edges like Flitz left.
For our purposes, Wright's is the best copper cleaner.
We checked all the copper surfaces 1, 2 and 3 weeks after polishing to see how well they kept cleaning. None of the copper polishes interfered in the germ-killing abilities on any of the copper surfaces we tested.
Copper Placement & Rust
Galvanic Corrosion, Bimetallic Corrosion and Dissimilar Metal Corrosion
Putting strips of copper tape onto high-touch surfaces is a great way to cut down on germs. We put them on doors, machine handles and equipment that people frequently touch or lean against. The problem we had was when we used it on our entryway door.
The entry door to our business is metal, designed for 180 mile an hour hurricane winds. Our business is located about a quarter of a mile from the ocean. Those two things are important to remember.
When we put the strips of copper on the metal door, within three days, we noticed the door handles were rusting. What we were experiencing was something called galvanic corrosion.
Galvanic corrosion happens when two different metals make contact, and they are exposed to an electrolyte. An electrolyte is something that allows the flow of current. In our case, the electrolyte was the salt air.
Those copper strips on that metal door, exposed to the salt air was causing rust at a dramatically accelerated pace. Door handles that had been rust-free for four years would rust out in a matter of months. We had to replace the copper strips with another type of antimicrobial push plate.
If you see corrosion on surfaces you've put copper tape on, you may be experiencing this problem. You should consider other antimicrobial options.
Galvanic corrosion on a door handle.
Copper Testing
When we ordered copper tape to put on high-touch surfaces, we wanted to make sure it was real copper. This is the simple test we used.
Mix 1/8 of a teaspoon salt with 3 tablespoons vinegar. Once the salt is dissolved, put a drop on the copper tape. After about 4-6 hours, if it's copper, you'll see the green tarnish where the drop was.
In the picture below, you can see the pure copper and copper tape. They both have the distinctive green/blue patina that copper gets when it corrodes.
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