The plumbing in my house is entirely copper, and I noticed there’s some green residue forming on the outside so, I wanted to know how to clean copper pipes.
I looked at what certified plumbers recommend, and here’s what I found.
Use white or apple cider vinegar and a soft brush or plumber abrasive paper to clean the outside of copper pipes. To clean the inside of copper pipes, use a wire brush that is the same size as the pipe. For example, if you have a ¾ inch copper pipe, use a ¾ inch wire brush.
Wire brushes used for cleaning pipes are available from any hardware store. The issue with cleaning the outside of copper pipes makes it easier for more green residue – known as verdigris to form.
Therefore, you should only clean the outside of copper pipes that people will see or that you don’t mind cleaning often.
Below, I will explain exactly how to clean both the inside and the outside of copper pipes in detailed steps.
How to Remove Oxidation From Copper Pipes?
Oxidation is the green residue that forms on the outside of copper and is very easily removed once you know how to. Based on seeing a lot of people use this method themselves and the results they got, here’s a technique I found that prove to be the best:
Wipe some vinegar, lemon juice, or lime juice onto the surface of the copper using a soft cloth. Then apply some table salt and rub it around on top of the liquid you used. Leave it to sit for 15 minutes or so, and then wipe it off. If it is stubborn to remove, use plumbers’ abrasive paper.
Combined with salt, the acid in vinegar, lemon juice, or lime juice will create a chemical reaction with the oxidation and break down the oxidation. The liquid also acts as a lubricant and makes it easier to wipe down.
Plumber’s abrasive paper is widely available at hardware stores. Avoid using any stiff metal brushes as an alternative, as they will create deep scratches visible on the surface of the copper pipes.
How to Clean Green Off Copper Pipes?
Copper pipes are generally secured in place by screws or nails so that as the water flows through them, they don’t move around and create a lot of noise. But, it isn’t easy to clean the side that’s up against the wall because of that.
You’ll need to remove copper pipes from where they are before cleaning them, which can be a bit labor-intensive. Also, if the copper pipes won’t be seen, it’s better not to clean the green off of them to avoid them from thinning.
Copper pipes for water lines need to be a certain thickness to hold the water pressure. If the pipes are too thin, it wouldn’t be long before they develop leaks and rupture.
Therefore, unless your copper pipes are exposed where people will see them, it’s best to leave the verdigris on them as it will act as a barrier between the air and the copper. To explain how this works, here’s a table that shows the chemical formula of copper pipes based on the different colors it exhibits:
| Chemical Formula | Color |
|---|---|
| Cu | Color of copper – orangey red |
| Cu2O | Color of copper – orangey red |
| Cu2O | Dark grey |
| exCuyS | Gold |
| CuS | Blue |
| Cu5FeS4 | Golden brown to copper color |
| Cu4SO4(OH)6 | Green |
If you’re rusty on your chemistry – excuse the pun; it’s not important what all the symbols and numbers mean. The key takeaway is that copper pipes will have a different color outside depending on their chemical composition.
These occur because the copper pipes are made of 99.99% copper, which has the chemical symbol Cu. The air you breathe is a gas that is made up of lots of different chemical elements. These will bind to the copper and create a different color on its surface.
When you remove the residue on the surface, which is a mixture of Cu (copper) and other elements such as O (oxygen) or H (hydrogen), you expose the fresh copper, which is more reactive with the air and will allow more residue to form. The residue will also form at a faster rate than if the surface has a residue on it.
How to Keep Copper Pipes Shiny?
Now that you know how to remove all of the residue on the surface of your copper pipes, there are some ways to keep them shinier for longer and protect them from the elements. Here’s what they are…
There is a range of copper protectants on the market, but a long-standing and trusted brand is Brasso. It is well known for cleaning copper, giving it a very attractive shine, and adding a protective layer that makes residue on the outside form slower.
It’s also very easy to use. When looking at the different copper protectants on the market, it’s difficult to know if any of them are any good, and it can be a bit hit and miss sometimes. However, Brasso is tried and true and always works.
Follow the instructions on the Brasso label to use it on your copper pipes. But, it’s as simple as wiping some onto it with a cloth, then rubbing it with a soft cloth until you get a really bright shine.
How to Clean the Inside of a Copper Pipe
You may also want to clean the inside of some copper pipes to remove any minor debris and to reduce friction on the water that flows through it. To do that is very easy; here’s how:
Use a circular wire brush available at virtually all hardware stores to scrub the inside of the pipe. Also, apply a mixture of vinegar and salt to the brush as you scrub it. Each wire brush is designed for a specific pipe size. For example, a half-inch wire brush will fit perfectly in a half-inch copper pipe.
Copper pipes used in plumbing are typically ½ an inch (12.5 mm) or ¾ inch (19 mm) in diameter. The diameter of copper pipes is the same whether they are M type or L type copper pipes.
Technically, L-type pipes are only about 0.01 inches (0.3 mm) thicker than M-type pipes. But, the same sized wire brush regardless of whether the copper pipes are L or M type.
I wrote an article that explains the major differences between the different types of copper pipes used for plumbing and where each of the different kinds of copper pipes is used in a plumbing system. Could you read it here?
