Aluminum corrosion is a common issue in the aluminum industry, primarily due to its resistance to corrosion. It is a reactive metal that naturally forms a thin coating of aluminum oxide. However, it eventually succumbs to corrosion due to factors such as fertilizers, industrial plant processes, pollution, or acid rain. The two most common forms of coil corrosion are pitting and formicary, which can occur within a few weeks after installation.
Pitting occurs when dissimilar metals in the presence of water containing an electrolyte, such as salty water or moisture. Aluminum in humid, salty environments is at risk of pitting, while dirt can also cause pitting corrosion. Excessive exposure to water, chemicals, and cleaning products containing fluoride and chloride can cause pitting corrosion. Reasons for this corrosion range from the use of subpar copper to chemical residues left over from manufacturing processes.
Formicary corrosion is more common due to a chemical reaction between oxygen, water, and a volatile organic compound. Formicary corrosion is more common in areas with high humidity and temperatures between 20 to 40°C.
Aluminum is susceptible to filiform corrosion in a relative humidity range of 75 to 90°C and temperatures between 20 to 40°C. The two most common forms of corrosion are pitting and formicary, which can occur within a few weeks after installation.
In conclusion, aluminum corrosion is a significant issue in the aluminum industry, with various factors contributing to its susceptibility to corrosion. Understanding these factors can help prevent and mitigate the potential damage to aluminum-based alloys.
📹 Preventing Corrosion on Aluminum Evaporators
This videos shows how to make an aluminum evaporator coil last longer by raising it out of the condensate water line.
How do you stop corrosion on aluminum?
In order to prevent pitting corrosion on aluminum surfaces, it is recommended that surface treatments such as painting or anodizing be employed. To achieve a durable and aesthetically pleasing surface, it is recommended that a clear coat or thin anodic coating be applied. Furthermore, the regular cleaning of the surface with mild alkaline or acidic detergents can also assist in the minimization of pitting. The aforementioned recommendations can assist in maintaining the visual appeal of aluminum while deterring corrosion in construction applications.
How do you remove white powdery corrosion from aluminum?
To clean oxidized aluminum, use household alcohol, methylated spirits, or Meudon whiting. Apply a few drops of rubbing alcohol to a damp cloth and apply to the surface. If the surface isn’t heavily oxidized, contact industrial cleaning professionals. Meudon whiting is a natural product made from chalk extracted from Meudon quarries, which is slightly abrasive but doesn’t scratch the material. Dilute Meudon whiting powder with water and mix until a liquid paste forms. Dip a cloth in the paste and rub the surface, ensuring thorough cleaning. Allow the surface to dry before absorbing the mixture.
Do aluminum evaporator coils rust?
Aluminum coils offer superior oxidation protection, prevent formicary corrosion, and are more resistant to pinhole leaks, extending the lifespan of your HVAC system. Leaks in a coil can cause loss of refrigerant and are costly to repair. Over the past few decades, more service technicians and brands have trusted aluminum’s durability over copper. To care for your outdoor/indoor HVAC system, Logan Services recommends pairing a cased coil with the inside unit when possible.
Regular cleaning of HVAC coils during annual maintenance visits is recommended for any brand or material. If your air conditioner is losing efficiency during warmer weather, it may be due to evaporator coil issues. The team at Logan Services serves the surrounding areas, offering HVAC replacement, repair, and routine maintenance.
What eats corrosion off aluminum?
Distilled water mixed with lemon juice or white vinegar can effectively remove most mild aluminum corrosion. Gently agitate the corroded area with a mild scrubbing pad. This solution requires elbow grease, exposure time, and luck. If stronger cleaning chemicals are needed, there are numerous options available on the market, specifically designed for oxidation removal on untreated and anodized automotive surfaces. However, if stronger cleaning methods are desired, there are numerous aluminum cleaning chemical products available on the market.
Why are my AC coils rusting?
Rust can cause failure in various systems components, such as coils and heat exchangers, due to excessive moisture and high temperatures. Engineers plan for rust to occur in specific order, protecting nearby metals. Rust, or “galvanic corrosion”, may not always be catastrophic but can indicate longevity and potential problems that can be repaired or resolved. In some cases, rust may be an indicator of longevity, suggesting that the problem can be repaired or resolved. For more information, visit a technical website.
How to stop corrosion on aluminum?
In order to prevent pitting corrosion on aluminum surfaces, it is recommended that surface treatments such as painting or anodizing be employed. To achieve a durable and aesthetically pleasing surface, it is recommended that a clear coat or thin anodic coating be applied. Furthermore, the regular cleaning of the surface with mild alkaline or acidic detergents can also assist in the minimization of pitting. The aforementioned recommendations can assist in maintaining the visual appeal of aluminum while deterring corrosion in construction applications.
What is the most common corrosion found on aluminum?
Aluminium corrosion can be classified into galvanic and pitting types. Despite its durability due to its protective oxide layer, aluminium also has weaknesses. To avoid corrosion, follow these guidelines. For specific projects, contact us for advice. Aluminum can be used in marine environments, but moisture and salt can degrade it less than marine grade alloys. It is important to consider these potential issues when working with aluminium.
How do I stop my air conditioner from corroding?
Anti-corrosion coatings like THERMAL-XR® can effectively prevent rust and corrosion on air conditioning units by creating a barrier between the metal surface and the environment. This coating uses graphene, an advanced carbon nanomaterial, to form an impenetrable shield against rust and oxidation. Its superior thermal conductivity improves heat dissipation in air conditioning systems. For more information on how THERMAL-XR® can improve HVAC system efficiency, contact us today.
What causes corrosion on aluminum?
Galvanisation occurs when different metals are positioned in an electrical circuit, resulting in one becoming stronger and the other weaker. Aluminium, due to its highly reactive nature, becomes the weaker metal, leading to corrosion. Extreme pH levels can also cause corrosion, as high levels can break down the aluminium oxide coating faster than it can repair itself. To avoid corrosion, untreated aluminium should be used in areas with a pH between 4.
5 and 8. 5. Although aluminium does not rust, it is essential to use it in the right environment to prevent corrosion. Typically, aluminium should not be used in areas with low or very high pH, as this allows the oxide coat time to regenerate in case of abrasion or mechanical damage.
What is the white corrosion on aluminum?
Aluminum, unlike iron or steel, doesn’t rust away in most conditions. However, when exposed to water and oxygen, it quickly corrodes, resulting in a thin, hard layer called aluminum oxide. This oxide, which appears as a powdery white or dull gray coating, hardens and forms a protective layer over the exposed areas of corroded aluminum. The process of aluminum corrosion is halted by oxidation, and unlike rust, which has a flaky, orange appearance, aluminum oxidation cannot be easily chipped off the metal surface.
The rate of aluminum oxidation varies depending on the type of aluminum, finish, and environment. Aluminum 5052, known as the “Hulk of aluminum alloys”, is known for its durability and excellent corrosion resistance. Aluminum 3003, the most widely-used aluminum alloy, is also good at resisting corrosion but less favorable to anodizing, a factory process that mimics the natural process of oxidation to create a more durable metal with a corrosion-resistant finish.
What corrodes aluminum quickly?
Stainless steel is a versatile material with excellent corrosion and rust resistance, making it suitable for various industries. Its heat resistance is superior to aluminum, with a resistance up to 2500°C, while aluminum can only withstand temperatures up to 400°C. However, in colder temperatures, aluminum’s strength increases, making stainless steel more brittle. Stainless steel’s strength is notably greater than aluminum, as it is denser and stronger, but its strength-to-weight ratio is lower, making it more suitable for applications like aerospace.
📹 What causes formicary corrosion
Formicary corrosion is not caused by chemicals in your air. In this video I explain what I believe is the cause and how you can fix it.
This has been a major issue in our industry for the pass 7-10 years. One would think as a manufacture that gives a 10 year warranty on these coils that they would have all this figured out. Its not like this is a brand new technology. They have only been at this for over 100 years now…. Great articles good sir keep up your excellent workmanship.
Im a service tech working in South Florida and have an office building with LG vrf systems. We typically lose two or three evaporator coils per year ever since the building opened. We changed out half of the building to Daikin vrv and still have the same issue even with coated coils. We’ve had third-party testing done, and the manufacturer has been out also, but no one can give us a straight answer of what exactly is causing. I worked in buildings with Chinese drywall that has high sulfur, but that’s not the case here (the copper is not black).
Really enjoying the articles. I’ve been looking for some information about how to pick a reliable system that will avoid issues like leaks. Do you have any suggestions about how to go about getting a replacement system. I have old ducts and a 30 year old Trane that is about dead due to leaks. So far I’ve gotten all aluminum evap and get a load calc as part of the install. Would love some more info. Location is gulf south. Thanks!
Is there any connection to when the white armor flex linesets came out to when all the leaking coils started happening? We had all kinds of problems with the white armor flex. I was thinking that some kind of reaction was happening to the copper coming from the white armor flex because you would see the copper refrigerant lines get holes from the outside in also not just the coils