Brass cleaning guide: Removing severe corrosion safely

October 14, 2024

Brass corrosion:

Like other metals, brass is an alloy mostly composed of copper and zinc that can corrode in specific types of environments. Brass is vulnerable to corrosion from air, water, and chemicals. The following explains the primary forms of corrosion that brass may encounter.

Tarnishing (Oxidation) in Air:

When brass is exposed to air, the oxygen in the surrounding air can react with the alloy's copper component, forming a copper oxide deposit on the surface. We refer to this process as tarnishing.

Dezincification in Water:

Brass is prone to a process called dezincification when it comes into contact with water, especially in harsh conditions like seawater or acidic solutions. This kind of corrosion leaves a porous, brittle structure rich in copper behind as the zinc component selectively leaches out of the brass alloy.

Stress Corrosion Cracking (SCC):

Another failure mechanism that can happen to brass under tensile stress in the presence of corrosive conditions, including ammonia or nitrates, is known as stress corrosion cracking (SCC). As a result, fractures begin to form and have the potential to spread throughout the metal.

Pitting Corrosion:

When brass is exposed to extremely harsh situations, including water with high amounts of chlorides (like seawater), it can develop another type of corrosion called pitting. Over time, the material may become noticeably weaker due to the localized pits or holes caused by this form of corrosion on the brass surface.

Corrosion:

Metals deteriorate naturally through a process called corrosion that results from chemical reactions with their surroundings. Corrosion is accelerated dramatically in humid or salt spray conditions because the presence of moisture and salts intensifies the chemical processes.

Oxidation and reduction are two simultaneous electrochemical events that cause corrosion.

Moisture creates an electrolyte on metal surfaces in humid environments, accelerating corrosion. Water allows ions to move from corroding to non-corroding areas. Even a thin layer of water can promote corrosion under high humidity.

In salt spray environments, like coastal areas or industrial sites using salt, corrosion speeds up further. When salt dissolves in water, it forms a highly conductive electrolyte, enhancing the corrosion process.

Localized corrosion, such as pitting and crevice corrosion, often occurs where chlorides concentrate in cracks or pits. High humidity and salt create ideal conditions for rapid corrosion. This localized corrosion can be severe and may go unnoticed until significant damage has occurred.

Common types of corrosion and their effect on the appearance and function of brass:

Brass can also develop surface corrosion. When exposed to airborne oxygen and moisture, it forms a layer of copper oxide, which may darken over time, giving the brass a dull, brownish appearance. This surface tarnish is primarily aesthetic and doesn’t affect the brass's performance or mechanical properties.

Patina, a type of copper corrosion, forms over time on copper-containing metals like brass, especially in outdoor environments. It occurs when brass combines with oxygen, carbon dioxide, and moisture, creating a green or blue-green film. This patina is often seen as visually appealing, adding a classic look to sculptures and architectural elements.

Additionally, the patina acts as a protective layer, preventing further corrosion of the underlying metal. While it affects appearance, it usually doesn't impair functionality unless corrosion becomes severe or uneven.

Electrolytic corrosion happens when brass comes into contact with another metal in the presence of an electrolyte. Environmental conditions that are high in moisture and salt, such as those found in the sea, are conducive to this kind of corrosion. On the surface of the brass, electrolytic corrosion may cause pitting, discoloration, or the formation of spots. The mechanical qualities of brass can be significantly impacted by this kind of corrosion.

Cleaning of brass:

Tools needed for brass cleaning:

To clean brass, you need a soft cloth, toothbrush, baking soda, lemon juice, vinegar, and water. These common items gently remove dirt and rust without damaging the brass.
The Copper Tube Pipe Cleaning Brush from Alsavo is designed to thoroughly clean brass pipes and valves, leaving a smooth surface for maintenance. It can be attached to power drills for faster and more efficient cleaning.

Brass cleaning brush available on Alsavo platform

Safety precautions when handling corrosive materials:

Safety is the priority when working with chemicals and caustic materials. Take these safety measures to keep yourself safe:

Wear Gloves: Always wear chemical-resistant gloves, like rubber or nitrile, when handling corrosive materials. They protect against burns, irritation, and absorption of harmful substances.

Wear Safety Glasses: Always wear safety goggles or face shields to protect your eyes from splashes, vapors, and fumes that can cause serious irritation or damage.

Use a Mask or Respirator: Wear a mask or respirator to avoid inhaling harmful fumes that can damage your respiratory system, depending on the chemicals you're using.

Ensure Good Airflow: Work with chemical cleaners in well-ventilated areas. Open windows or use fans to allow fresh air in and prevent harmful fumes from building up. Poor ventilation can cause headaches, dizziness, and long-term health issues.

Avoid Direct Skin Contact: If your skin comes into contact with chemicals, wash the area with water immediately and seek medical help if irritation persists. Never touch your face, especially your eyes, when handling caustic materials.

Examine product labels: Always follow the manufacturer's instructions and warnings when using chemical cleaners.

By taking these steps, you can safely handle corrosive materials and chemicals in your office.

Steps to Clean Heavily Corroded Brass:

Manual Cleaning Methods

Cleaning with Natural Cleaners (Vinegar and Lemon Juice) For minor corrosion, natural cleaners like vinegar and lemon juice are effective and gentle.

Step-by-Step Instructions:

Mix equal parts white vinegar and lemon juice in a bowl.
Submerge the brass item in the solution, or apply it generously using a soft cloth if the item is too large.
Use a soft cloth or an old toothbrush to scrub the corroded areas. Avoid using anything abrasive that could scratch the brass.
Once the corrosion is removed, rinse the brass thoroughly with warm water.
Dry the brass completely and polish it with a clean, dry cloth to restore shine.

Baking soda paste for deeper cleaning:

A paste made from baking soda and water can help with deeper cleaning.

Step-by-Step Instructions:

Mix baking soda with a small amount of water to form a thick paste.
Spread the paste onto the corroded areas of the brass.
Gently scrub the brass with a toothbrush or cloth, focusing on areas with visible corrosion.
After cleaning, rinse the brass with warm water to remove the paste.
Dry the brass completely and buff it with a soft cloth to enhance its luster.

Methods of Chemical Cleaning
Commercially available brass cleaners may be required for more severe corrosion. These cleaners contain stronger ingredients intended to remove deeply ingrained oxidation.

How to Safely Use Chemical Cleaners:

When working with chemical cleaners, make sure to put on safety glasses and gloves.
Refer to the product label for application instructions. Usually, use a soft cloth or sponge to apply the cleanser.
Give the cleaner the suggested period of time, generally a few minutes, to sit on the brass.
After thoroughly rinsing the surface with warm water, use a non-abrasive cloth or brush.
Drying correctly means patting down the brass with a towel and letting it air dry entirely to prevent water stains.

Crucial Safety Advice: To prevent fume inhalation, use chemical cleansers only in well-ventilated areas. After cleaning, make sure the brass is completely rinsed to stop any chemical residues from further corroding the metal.

Techniques for Electrolytic Cleaning
An efficient, non-invasive technique is electrolytic cleaning for brass objects with complex designs or severe corrosion. With this method, corrosion is removed using an electric current without causing any damage to the brass.

The Operation of Electrolytic Cleaning

In a plastic container, mix water and washing soda (sodium carbonate).
A sacrificial anode, such as stainless steel, should be connected to the positive terminal in the solution, and the brass object should be connected to the negative terminal of a power source (such as a vehicle battery charger).
For a few hours, let the current flow through the solution. The brass's corrosion will be eliminated by the electrolytic reaction.
Once the process is complete, remove the brass, rinse it thoroughly with clean water, and dry it completely.

Best Uses: This method is ideal for complex brass accessories like valves, fittings, and decorative items, as it can clean deep crevices without physical scrubbing.

Conclusion:

These methods allow for a range of brass cleaning, from gentle natural solutions for minor corrosion to more advanced techniques like electrolytic cleaning for complex and heavily corroded items.

Protecting the Brass Surface

Putting a protective layer on brass surfaces is crucial to preventing corrosion in the future. Applying a brass protectant and varnishing are two popular techniques:

Application of Varnish: Brass is protected from the elements (air, moisture, and chemicals) with a clear varnish. To make an application:

Before varnishing, make sure the brass is clear of rust and grime.
Apply a thin layer of varnish with a brush. Allow it to fully dry before applying any more coats if needed.
To guarantee enduring protection, give the varnish time to completely cure after application.

Brass Protectants: Without changing the brass's appearance, brass protectants offer a specific solution by offering a transparent, non-tacky shield that prevents tarnish and corrosion. Alsavo offers brass valves and fittings with protective coating materials that are perfect for extending their lifespan by reducing environmental wear.

Tips for Regular Maintenance

1.Continual Cleaning: Regular wiping and cleaning are essential to keeping brass shiny and preventing re-corrosion.

Dust the brass once a week with a gentle cloth.
To get rid of dirt, wash the surface with warm water and a small amount of soap. Dry completely to prevent wet patches.
To keep the surface smooth and bright, use brass polish occasionally. Be careful not to be overpolished, though, as this can erode the protective layers.

2.Brass valve maintenance:

When it comes to brass valves that are in operation, keep an eye out for wear and corrosion, particularly around joints and seals.
To lessen wear and friction, lubricate moving parts using the proper substances.
Use a corrosion inhibitor or keep the region dry to safeguard brass valves in damp settings.

By taking these precautions, you can preserve the superior condition of brass accessories—such as valves and fittings—and avoid damage caused by prolonged exposure to adverse environments.

Conclusion: The importance of keeping brass clean and corrosion-free

Regular cleaning and maintenance of brass are crucial for extending its service life and ensuring its proper functioning. Here are the key reasons why brass maintenance is essential:

Prevention of Corrosion: Brass is naturally resistant to rust, but it can corrode when exposed to certain environments, such as moisture or chemicals. Corrosion weakens the brass surface, leading to damage that can affect both its appearance and structural integrity. Regular cleaning helps to remove corrosive agents and protect the brass from further deterioration.
Extending Service Life: By preventing corrosion and wear, regular maintenance significantly extends the lifespan of brass items. This is particularly important for brass fittings, valves, and accessories used in industrial and residential applications. Clean and well-maintained brass is more reliable and less prone to failure over time.
Ensuring Proper Functionality: In systems where brass valves and fittings are used, such as plumbing or heating systems, corrosion can lead to blockages, leaks, and malfunctions. Keeping these components clean and free of corrosion is essential to ensure the smooth operation of the entire system. For instance, in industrial settings, brass components must be in excellent condition to maintain safety standards and operational efficiency.
Preserving Aesthetic Appeal: In addition to its functional importance, brass is often chosen for its visual appeal. Regular maintenance, including polishing and cleaning, keeps brass looking shiny and attractive, making it suitable for decorative purposes in homes and buildings.

By maintaining brass regularly, users can avoid costly repairs, reduce the risk of system malfunctions, and ensure that the brass maintains its beauty and functionality over time. Whether in industrial systems or home applications, keeping brass fittings and valves corrosion-free is essential for long-term efficiency and safety.

FAQS

1.Can I use household items to clean brass without causing damage?

Yes, you can use household items to clean brass safely without causing damage. Common items like vinegar, lemon juice, baking soda, and salt are effective and gentle on brass when used correctly.

2.What are the signs that brass is too corroded to be cleaned effectively?

Brass can reach a point where it is too corroded to be cleaned effectively. The signs that indicate the brass may be beyond restoration are deep pitting, flaking or peeling, discoloration beyond the surface level, brittleness or cracks, loss of detail, and corrosion spreading under coatings. If you notice these signs, it may be difficult or impossible to fully restore the brass, and it might require professional treatment or replacement depending on the item's use or value.

3.How often should I clean and maintain brass fixtures?

Brass fixtures should be cleaned every 1 to 3 months, depending on their use and the environment they are in. Any signs of tarnish or wear should be regularly checked, consider applying lacquer coating to slow down tarnishing.

4.Is there a difference between cleaning antique brass and modern brass fittings?

Yes, there is a difference between antique and modern brass fittings. They have different finishes, cleaning methods, and maintenance.

5.What are the best products to use for preventing brass corrosion?

To prevent brass corrosion and maintain its appearance, you can use a few different products: