Green copper pipe corrosion (3 preventative methods) - Free from Rust (2023)

This blog post will explain the topic, “green copper corrosion” and cover topics like why are copper pipes greening, how to remove the patina from copper pipes, and frequently asked questions.

What causes green corrosion on copper pipes?

Green corrosion on copper pipes is caused by oxidation. Oxidation causes tarnish, or the greenish color that occurs on copper pipes. When copper is exposed to moisture and oxygen for an extended period of time, it oxidizes. While the oxidized layer isn’t dangerous, it does damage the copper. It’s crucial to keep in mind that the patina is not really the issue.

Why Are Your Copper Pipes Greening?

Copper is one of the greatest materials for your house pipework, although it might become green on occasion. This is caused by copper’s long-term contact with oxygen and other atmospheric elements. Patina is the word for the green color on your copper pipes.

If you see this green color on your pipes, it’s a sign that something isn’t quite right. If you see a green tinge, you should have a professional plumber inspect the condition.

It’s not always simple to remember your pipes when it comes to the protection of items around the house. We seldom worry about the plumbing in our houses until there is an issue, such as a leak or a blockage.

When the substance in your pipes becomes old and worn, you may not even notice you have a problem. Copper pipes, for an instance, will become green, which may be induced by a variety of factors.

Pipe Material Types

The plumbing materials used by homebuilders have evolved throughout time. Pipes consisting of iron, steel, or even lead are often seen in older dwellings. More contemporary residences, on the other hand, will almost certainly be equipped with PVC or copper tubing.

These materials are simpler to work with, lighter, and have a longer lifespan. PVC and copper are much less prone to corrosion and can be reused, making them ideal for ecologically conscious builders. Copper, for an instance, is recognized for being a hard and durable metal.

What is the cause of the green color on copper pipes?

Oxidation causes tarnish, or the greenish color that occurs on copper pipes. When copper is exposed to moisture and air for an extended period of time, it oxidizes. While the oxidized layer isn’t dangerous, it does create corrosion in the copper. Copper oxide is the green color, and it is caused by the metal decaying.

The Statue of Liberty in Nyc is one of the most well-known examples of copper oxide. The greenish color is the result of the copper oxidizing on the exterior of the statue, which has been around for a long period.

(Video) How to Stop Copper Pipe Corrosion | Ask This Old House

It’s crucial to keep in mind that the patina isn’t the issue. Your copper pipes may benefit from a coating of corrosion. This is due to the fact that it develops a more water-resistant tube that is less susceptible to other reactions.

The patina on copper tubing, on the other hand, indicates that the plumbing operation was not completed properly in the first place.

Patina’s Effect on Your Plumbing

Patina might indicate that your pipes are leaking. It may also result in larger leakage, which will be more expensive in the long term. Furthermore, drinking water that has traveled through copper tubing and has a green color is harmful to your health. It may harm your skin and hair as well as create health concerns.

It’s possible that the leaks generating corrosion on your copper pipes aren’t particularly large. Instead, tiny fractures in the pipe might be the source of the issue.

There are three major reasons why this can be a problem:

  • Water from a well.
  • Chloramines.
  • Corrosion of particles.

Water from a well

If the pH level in well water is too low, it might harm the pipes. If your water comes from a well and your copper tubing has patina, it’s a good idea to check the pH level of your well liquid. Anything below 6.5 degrees Celsius might create problems in your pipes. It might be the source of the pinhole leakage. It also has the potential to allow the lead to leak into your water system, posing a major health danger.


This chlorine-and-nitrogen-based chemical is often used to sanitize municipal water sources. They might, however, be the source of your copper tubing developing small holes and leaking, resulting in patina and a larger issue for you.

Corrosion of particles

Corrosion may occur in old pipes and water heaters, causing metallic fragments to come into touch with your copper tubing. These metallic fragments might be scratching the copper, creating pinhole leaks.

Resolving the Patina Issue

It’s unpleasant to see a greenish color on your copper pipes. You may be worried if you discover that your home’s plumbing is not performing as well as it might. There are, nevertheless, certain methods for repairing tiny leakage in copper pipes. The more pressing dilemma is what to do with your copper tubing that has already developed a patina.

Because the source of your pipes’ degradation may not be something you can manage, it may be advisable to consider replacing them. While this may seem to be a difficult and costly repair, it may save you money in the long run if your pipes persist to leak.

(Video) How to Clean Corrosion Off of Copper Pipe Joints

Whatever is creating the leaks, it is recommended to contact a professional plumber who can assess the problem and assist you in repairing or replacing your pipes so that the water passing through them is acceptable to use in your house.

What Causes Copper Pipes to Green?

The following are the two most common causes why copper pipes become green:

  • Chemical Interactions
  • Corrosion

I will now elaborate on them.

Chemical Interactions

When the color of your pipes changes from deep green to black, it’s generally due to the presence of sewage gas. Copper darkens as a result of high sulfur content, giving a distinct deep green or even black

tint. This might also indicate that your pipe came into touch with non-compatible metals like galvanized steel.

While this isn’t very harmful, it may be a risk. This is particularly true when working with low-cost copper. Builders may use low-cost copper with a significant impurity content to create pipes. There’s no chance you’ll see this at first. However, these contaminants will eventually show up on the tube’s surface, darkening it.

The copper of lower grade may break more quickly than copper of higher quality. Not to mention the fact that you have no idea what it’s comprised of or if it poses a health risk. It’s critical to put your faith in your plumber at all times.


Corrosion is the primary cause of copper pipe corrosion. In reality, when copper is exposed to the atmosphere, it oxidizes, resulting in a patina. While short-term exposure isn’t a problem, it does result in patina over time. Patina is the oxidized coating on copper that has become green or bluish-green in color.

Copper oxide, a byproduct of copper combining with oxygen, is responsible for the hue. While patina is really not hazardous in and of itself, if left unchecked, it will corrode the pipe and cause it to explode. The green tint you see is really the copper rusting. Copper oxidizes to a green tint, while iron corrosion is often observed as red.

How to remove green corrosion from copper pipes?

Because many common home chemicals are acidic, the patina interacts with them, which is a good thing. These are the ones that can provide you with the greatest outcome.

(Video) How to Clean Copper Metal : Copper Pipes & Fittings

  • Lemonade
  • Coffee in its natural state
  • Vinegar

I will now elaborate on the guidance given above.


Lime juice is very acidic, which makes it an excellent cleaning agent. It also has a pleasant aroma, which is always a plus.

Steps of removing green corrosion with lemonade:

  • To prepare a decent lime juice for cleaning, use 1 part tap water and 1 part lime juice.
  • Dip the pipe in it for approximately half an hour before brushing it clean.
  • This should be sufficient to remove the unsightly green tinge.

Coffee in its natural state

Coffee seems to be the last item on your mind when it comes to cleaning. Everything, from clothing to teeth, is stained. It is, however, quite acidic, which makes it ideal for cleaning the patina. Unless the tubes are designed to withstand very extreme temps, don’t use hot coffee.

Allow the coffee to cool before soaking the pipe in it, exactly as you would with lime juice. Just make sure you don’t spritz it on the walls since it can ruin them! Wait a few minutes before scrubbing everything down with a brush or a moist towel. This will restore the appearance of your pipe.


All vinegar is quite acidic. It really doesn’t matter whether it’s black vinegar, apple cider vinegar, or white vinegar; it’s all acidic. It’s so acidic, in fact, that you don’t even need to immerse the pipe in it. Spritz the pipe with pure vinegar and scrape it with a cloth or brush. Allow the vinegar to settle for a few minutes before scrubbing again if the hue persists. This is fantastic for old spots that just won’t go away.

Steps of removing green corrosion with vinegar:

  • Prepare a mixture of vinegar, salt, and flour if you want to go the extra mile.
  • Combine a teaspoon of salt, one cup of vinegar, and the necessary quantity of flour in a mixing bowl.
  • This may make creating a combination that will sit nicely on the pipe before washing simpler. It’s not always essential to use flour; sometimes it’s just for texture.
  • After you’ve removed the patina of the pipe, wipe it all down with olive oil.
  • The pipe will sparkle like new after being cleaned with olive oil. It also won’t harm anything and is completely safe to use without leaving an adhesive residue.
  • This will give the visible section of your pipe system a more luxurious appearance.
Materials Needed

Frequently Asked Questions(FAQs), “Green copper corrosion?”

What causes green corrosion on copper water pipes?

Copper is removed out of the pipes and subsequently stored elsewhere, causing copper pipe green corrosion. As the copper in your pipes deteriorates, you may notice small pinhole leakage.

How do you stop copper from oxidizing?

Spraying or painting copper with a specific sort of sealer is a fast and simple technique to keep metal from deteriorating. This sealer is typically easily accessible on the market and does an excellent task of maintaining copper parts airtight.

How do you clean corroded copper?

  • To produce a thick paste, combine ¼ cup salt, ¼ cup flour, and enough vinegar to form a paste.
  • Massage the paste onto the copper’s surface using a delicate cloth. Buff the copper object to a gleaming finish.
  • Rinse well with lukewarm water and dry completely.

What does green on pipes mean?

Sewer and drainage lines are green pipes. Recovered wastewater is transported via lavender or violet pipelines, where it is filtered and disinfected before being reused for agriculture.

(Video) Folsom Releases Findings From Study After Pinhole Leaks In Copper Pipes

What happens to copper when it oxidizes?

Oxidized copper is a kind of rust that occurs when copper oxidizes to cu2o, then cuprous or cupric sulfide, and ultimately copper carbonate in a 3 step process. It results in the formation of a green-colored copper coating, or tarnish, over time.

Can copper pipes corrode?

Copper is, in fact, more corrosion resistant than iron and steel. Copper and lead, on the other hand, are susceptible to a variety of different forms of corrosion. If your copper tubing is spilling, you’ll need our help to fix or replace them so that the problem doesn’t happen again.


(Video) Corroded Pipes and Valves


How do you stop green corrosion on copper pipes? ›

Dry the pipe to prevent further corrosion. Another method is to use salt alone. Sprinkle salt on a damp piece of cloth and rub it onto the green corrosion. Leave the salt on for a few minutes before wiping it off with the cloth.

What is the most effective method of removing corrosion from copper pipes? ›

First, wet a rag with acetone and wipe down the corroded green area for this method. Then, use a warm soapy washcloth to wipe the acetone off the pipe and dry the pipe extremely well. It's important to note that acetone is highly flammable, so stay away from open flames when using it.

What three methods can be used to join copper pipe? ›

Joining Methods

There are three categories of methods to join copper tubing: Solder or Brazed Joints, No-flame Joints, and Additional Joining Methods.

How do you protect copper pipes? ›

The easiest way to protect copper pipes is to simply coat the entire unit. Dissimilar metal connections are a weak point for corrosion protection and contribute to the inability of a unit to maximize its lifespan.

What can you put on copper to keep it from turning green? ›

Wax coating, lemon juice solutions, and lacquer spray are common options. On small copper items, the former are feasible ways to prevent copper from tarnishing.

How can you prevent oxidation of copper? ›

The protection of copper from oxidation can be achieved by alloying copper film with Ti, Pd, Cr, or Al. The influence of the composition and microstructure to the oxidation rate has been studied. The compounds Cu 3Ti, Cu 3Pd, and CuAl2 are stable in the oxidation ambient.

What are four methods of corrosion control that can be used on piping systems? ›

This technical bulletin will consider four methods of protecting carbon steel pipe supports components from corrosion; painting, zinc coatings, hot dip galvanizing, and combinations of these. Painting has an advantage when appearance and choice of color are important.

What is the most effective method of corrosion removal? ›

Corrosion Damage Removal Techniques. Following the evaluation, the removal technique is selected according to the extent of the damage. As described above, a mechanical removal method utilizing an abrasive tool is usually selected because it is the most effective and efficient solution.

What 4 methods of joining copper pipe do plumbers use? ›

Alternative Pipe Fitting Methods
  • Soldered Connections. In most settings, soldered connections are still the plumber's preferred method of fitting copper pipes. ...
  • Pro-Set or Clamp-on Fittings. Pro-Set fittings clamp onto the copper pipe. ...
  • Push-on Fittings. ...
  • Compression Fittings. ...
  • Solder is Here to Stay.

What are two methods for joining copper water pipes? ›

Brazing and press fittings are both reliable and acceptable joining methods for copper pipe. It appears that brazing is preferred for piping 2 inches and above, while press fittings are becoming the norm for piping below 2 inches in diameter.

What are the three alternative mechanical piping methods? ›

What are three alternating mechanical piping methods? Alternative mechanical piping methods are tubing conectors, Push on type fitting with internal gasket and metal teeth for grabing onto the pipe selection, and crimping the press type fitting to join two pipe sections.

Should copper pipe be wrapped? ›

Copper is naturally corrosion resistant to most soils and underground environments. Wrapping or sleeving the copper tube in an effort to provide an additional layer of protection, while well intended, can lead to failure due to improper sleeving or wrapping practices.

What is the best way to seal copper? ›

As a general rule of thumb you use Everbrite™ Protective Coating for Copper Outdoors; and ProtectaClear® for Copper Indoors. ProtectaClear® is also used for items subject to a lot of handling and abuse.

Do green copper pipes need to be replaced? ›

Green heating pipes do not necessarily need to be replaced, but if you see oxidation on the pipes, you should investigate to find the source. It could result from a pinhole leak in the pipe, faulty join, or dampness in a wall. If the corrosion is significant, the pipe may need replacement.

How do you restore green copper? ›

Lemon Juice + Salt

Create a paste with lemon juice (lime or orange juice works, too) and salt at a 3:1 ratio, respectively. Make sure salt is dissolved so as not to scratch the copper. Rub a small amount of paste on the soiled copper object with a clean cloth until you start to see the grime loosen up.

Can you clear coat copper pipe? ›

Copper and its alloys are extremely resistant to corrosion, but a superficial discoloring tarnish eventually forms with exposure to the atmosphere or handling. The appearance of these metals can be preserved by applying thin clear protective coatings to their surfaces.

Can you seal copper with polyurethane? ›

This is a non-yellowing low VOC two-part clear, durable, air drying polyurethane. It can be used on copper, brass, bronze, steel, wood, terracotta, ceramics, and concrete. It's engineered to provide superior resistance to UV light and harsh outdoor conditions.

What prevents oxidation from corrosion? ›

How to Prevent Corrosion
  1. Protective Coating. A fresh coat of paint will enhance the appearance of your metal structure and prevent corrosion. ...
  2. Metal Plating. Theoretically, plating is almost similar to painting. ...
  3. Corrosion inhibitors. ...
  4. Sacrificial coatings. ...
  5. Environmental Measures. ...
  6. Modifying the design.

Can you reverse copper oxidation? ›

Removing Oxidization from Copper

Combine 3 parts baking soda with 1 part white vinegar. Apply the cleaning paste to the copper. Use a plastic spatula or a similar tool to apply the paste to the tarnished copper. Completely cover all tarnished areas with the paste.

What causes copper to rust? ›

The presence of oxidizing acids; heavy-metal salts, sulfur, and ammonia; and a number of sulfur and ammonia compounds can cause corrosion to set in. Water that comes from a well is much more likely to contain these materials and put copper lines in jeopardy—but it can occur in the civic water system as well.

What are the three methods to prevent corrosion? ›

There are several cost effective ways to prevent corrosion including:
  • Use non-corrosive metals, such as stainless steel or aluminium.
  • Make sure the metal surface stays clean and dry.
  • Use drying agents.
  • Use a coating or barrier product such as grease, oil, paint or carbon fibre coating.

What is the prevention of rusting? ›

Two ways to prevent the rusting of iron are: Oiling, greasing, or painting: By applying oil, grease, or paint, the surface gets a waterproof coating and the moisture and oxygen cannot come into direct contact with the iron article. Hence, rusting is prevented.

Which is the best method to treat pipes with internal corrosion? ›

Chemical treatment is the main solution for many internal pipeline corrosion problems. Washing the pipe by chemical solutions pumping clears away any corrosion product. Coating and protection of the lining of the pipe by pumping chemicals is next in the process.

What are the four basic methods for corrosion control and corrosion protection? ›

The rusting of iron can be prevented by greasing, painting, galvanizing, anodizing, or oiling the surface.

What are the four 4 main types of corrosion with respect to boiler water that can damage the boiler? ›

Corrosion is a relevant problem caused by water in boilers.
For further information about the different types of corrosion check the following web pages:
  • Galvanic corrosion.
  • Caustic corrosion.
  • Acidic corrosion.
  • Hydrogen embrittlement.
  • Oxygen attack.
  • Carbon dioxide attack.

What are the three methods of preserving metals? ›

You have learnt three methods of protecting ferrous metals against corrosion: painting, galvanisation and electroplating. Protecting metals against corrosion makes the metals last longer, which could reduce the need for mining. You can also easily reuse a rusted piece of metal if you clean the rust off and paint it.

What are the five general corrosion removal steps? ›

In general, any complete corrosion treatment involves the following: (1) cleaning and stripping of the cor- roded area, (2) removing as much of the corrosion products as practicable, (3) neutralizing any residual materials remaining in pits and crevices, (4) restoring protective surface films, and (5) applying ...

What are the two types of corrosion removal methods? ›

The methods normally used to remove corrosion are mechanical and chemical.

What are the 4 types of copper tubing joints? ›

Copper tubing is joined using flare connection, compression connection, pressed connection, or solder.

What are 4 types of copper tube joints? ›

The three most common types of copper pipe used in residential and commercial construction are Type K, Type L, and Type M. A fourth type, used for drain-waste-vent, or DWV, piping, is found most often in some older homes.

What can I use instead of sweating copper pipe? ›

Copper press fitting is a flameless alternative to soldering copper pipe connections. In this system, a hydraulic tool is used to press specially designed connectors to join traditional pipes. These connectors house a sealing element that, when pressed, creates an even and reliable connection.

What is the purpose of annealing copper tubing? ›

By annealing the copper you can soften it to make it more workable and easier to bend. The process involves heating the copper to change its structure and allowing it to cool quickly. Set up the nitrogen and start purging the copper pipe before applying any heat.

What are the water pipe joining methods? ›

These joining methods include soldering, brazing and electric resistance. Soldered joints, with capillary fittings, are used in plumbing for water lines and for sanitary drainage.

What are the 3 most common materials used for water supply pipes in current construction? ›

The most common materials for the manufacture of water main pipes and fittings are metal (cast iron, ductile iron, steel, and copper), clay and concrete pipe (vitrified clay, reinforced concrete, and asbestos cement), and plastics (PVCs, HDPE, and fiberglass).

What are the three common types of piping used in construction? ›

Five types of pipe—PEX, PVC, ABS, copper, and galvanized—are commonly found in houses these days, both older homes and new construction.

What are the 3 main materials that pipe and fittings are made of? ›

The common materials used to make pipes include ferrous metals, non-ferrous metals and non-metals. Stainless steel, alloy steel and carbon steel are ferrous metals.

How do you protect exposed copper pipes? ›

The easiest way to protect copper pipes is to simply coat the entire unit. Dissimilar metal connections are a weak point for corrosion protection and contribute to the inability of a unit to maximize its lifespan.

How often do you strap copper pipe? ›

Hard drawn copper tube shall be supported at least every 8 feet for one inch and smaller tube, and at 10 foot intervals for larger sizes. Annealed copper tubing shall be supported at least every 8 feet.

Do you put plastic inserts in copper pipe? ›

No you do not use pipe inserts whilst using push fit on copper, but make sure you when using plastic barrier pipe, the best ones to use are the super seals.

What stops copper from corroding? ›

Wax coating, lemon juice solutions, and lacquer spray are common options. On small copper items, the former are feasible ways to prevent copper from tarnishing.

How can you prevent copper oxidation? ›

A TiN layer with oxygen incorporated is more effective in preventing copper oxidation than a TiN layer without oxygen incorporated. A passivating Si3N4 layer on copper thin films can prevent copper oxidation effectively at 350 °C in oxygen ambient.

How do you stop copper pipes from oxidising? ›

A quick and easy way to prevent copper from tarnishing is to spray or paint it with a special type of sealer. This sealer is usually readily available in the market and do a very good job of keeping an airtight seal on copper pieces.

Does green on copper pipe indicate a leak? ›

Green – Green or greenish colors on the outside of your copper water pipes means that you have water leaks in your copper piping and possible corrosion. The latter is especially true if the water itself is staining other items, like clothing, sinks, and fixtures.

Can you paint over green copper pipes? ›

While copper can be painted like most surfaces, is it a good idea? As long as you obtain the right kind of paint, you won't have to worry about the paint attacking or otherwise damaging the copper piping. If you're careful, painting a copper surface won't do any damage at all.

How many years does it take for copper to turn green? ›

In coastal regions or heavy-industrial areas, the natural patina typically forms within five to seven years. In the country and rural areas, where the level of sulfur dioxide in the atmosphere is relatively low, the patina formation takes 10 to 14 years to attain a dominant stage.

Can you restore copper that has turned green? ›

Mix 1/4 cup salt, 1/4 cup flour and enough vinegar to make a thick paste. Use a soft cloth to rub the paste on the surface of the copper. Buff the copper item until it shines. Rinse with warm water and dry thoroughly.

Why are my copper pipes turning green? ›

Oxidation is common on copper when it is exposed to water and air over time. While this oxidized layer is not harmful, it does cause the copper to become corroded. This green colour is known as copper oxide and is basically a rusting of the metal.

How do you fix green hair from copper pipes? ›

Get a Shower Filter

There are many different shower filters available that will help reduce mineral levels and remove the copper in the water turning your hair green.

Can you use CLR on copper pipes? ›

CLR (Calcium, Lime, and Rust Remover)

The problem with using CLR to clean your copper piping is that it can remove the finish off of it. Not only that, but it can also pit certain grades of copper, and that's definitely not something you want to have happen to your pipes.

Can you clean copper with hydrogen peroxide? ›

Can you clean copper with hydrogen peroxide? Because hydrogen peroxide reacts strongly with copper, it's recommended you avoid using hydrogen peroxide with your copper products.

What do plumbers use to clean copper pipes? ›

A metal polish that's suitable for copper, used according to the instructions, will usually get the best results. If you don't have metal polish to hand and you want a home solution, try dissolving a tablespoon of salt in a cup of white vinegar. Use a soft cloth to rub the salt-and-vinegar mixture onto the pipe.

Should I clean corrosion off copper pipes? ›

Copper oxidation can be removed from the pipes in several ways. A light solvent or light acidic solution with a light abrasive rub, such as salt, will generally remove the oxidation. There are many recipes for cleaning recipes for copper pipes. The strategy to prevent oxidation is regular cleaning.

How do you remove green oxidation from metal? ›

Soak It in White Vinegar

If possible, place it in a container so that it is fully submerged; otherwise, just make sure it's completely covered with vinegar. After 10 minutes, take it out and use your scrub sponge or brush to gently scrub away at the green corrosion.

What is the best chemical to clean copper? ›

What are the Best Chemicals to Clean Copper?
  1. Citric acid- Citric acid is an organic acid which works perfectly well for cleaning copper. ...
  2. Acetic acid- This is one of the most commonly used chemicals to clean copper. ...
  3. Acetone- Acetone is an organic compound which is most commonly used as a solvent.
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