In electrical installations, galvanic corrosion poses a significant threat, particularly when dissimilar metals such as aluminium and brass or aluminium and copper are used. However, galvanic corrosion doesn’t happen automatically—it requires a specific catalyst: an electrolyte. This means that in certain environments, the risk is minimal, while in others, it can be severe.
By understanding how electrolytes contribute to this process, and how Unial jointing paste prevents it, electrical installers can make informed decisions and safeguard their work.
What is Galvanic Corrosion?
For galvanic corrosion to occur, three key conditions must be met:
Two Dissimilar Metals
These have different electrochemical potentials (e.g., aluminium and brass).
An Electrical Connection
The metals must allow electron flow between them.
Presence of an Electrolyte
This is the critical factor. Without an electrolyte, such as moisture, the corrosion process cannot take place.
When these conditions are met, the less noble metal (the anode, e.g., aluminium) corrodes faster, while the more noble metal (the cathode, e.g., brass or copper) remains relatively unaffected. Over time, this weakens the joint both mechanically and electrically.
Electrolytes: The Catalyst for Corrosion
An electrolyte is any substance that allows electricity to flow between the metals. In most cases, this is moisture, which can come from:
Rainwater or Humidity
Common in outdoor environments.
Saltwater or Salty Air
Found in marine and coastal areas, which greatly accelerate corrosion.
Condensation
Occurs indoors due to temperature fluctuations, even in seemingly dry environments.
Industrial Chemicals
Moisture combined with certain chemicals can act as a potent electrolyte.
No Electrolyte, No Corrosion
If there’s no electrolyte, galvanic corrosion cannot occur, even when dissimilar metals are connected. For example:
In dry, controlled environments, aluminum and brass connections may remain corrosion-free indefinitely.
Temporary connections in low-risk environments may not require additional protection.
However, in most real-world scenarios, moisture exposure is unpredictable. Even minor environmental changes can introduce moisture, turning a previously safe connection into a corrosion risk.
How Unial Jointing Paste Protects Against Corrosion
Unial jointing paste is designed to eliminate the risk of galvanic corrosion by targeting its weakest link: electrolyte access. Here’s how it works:
1. Seals the Connection
The paste forms a protective barrier between metals, blocking moisture and other contaminants from reaching the surfaces.
2. Prevents Electrochemical Reactions
By isolating the metals from the electrolyte, it halts the galvanic process before it begins.
3. Maintains Electrical Efficiency
Despite its protective qualities, Unial paste ensures a low-resistance connection, critical for efficient power flow.
4. Long-Lasting Protection
Unial remains effective in extreme temperatures, from -30°C to 120°C, providing reliable performance across diverse environments.
Practical Applications of Unial Paste
Unial paste is indispensable in various scenarios where dissimilar metals are joined, particularly in environments prone to moisture:
1. Overhead Line Conductor Joints
Outdoor power lines are constantly exposed to rain, humidity, and salt-laden air, making them highly susceptible to corrosion. Applying Unial paste ensures these connections remain durable and efficient.
2. Transformer and Switchgear Connections
High-voltage equipment operates in environments with fluctuating temperatures and humidity. Unial paste protects these critical connections from corrosion and ensures long-term reliability.
3. Cable Terminations and Splices
When aluminium and copper cables are joined, galvanic corrosion can degrade the connection over time. Unial paste prevents this, ensuring secure and efficient joints.
4. Gland Bush to Gland Plate Connections
Gland plates are often installed at ground level above trenches, which may accumulate moisture. For example, a brass gland bush connected to an aluminium gland plate is highly susceptible to corrosion if water collects in the trench. Unial paste provides a protective layer, ensuring the connection’s integrity despite environmental challenges.
5. Lightning Protection Systems
Outdoor lightning protection systems face constant exposure to moisture and harsh conditions. Applying Unial paste ensures these critical safety systems remain corrosion-free and reliable.
Why Every Installer Should Use It.
While it’s true that galvanic corrosion requires an electrolyte, moisture exposure is often unavoidable. Even environments that appear dry can experience condensation or other sources of moisture. By applying Unial jointing paste, installers can:
Prevent Costly Failures
Protect joints from corrosion-related degradation.
Enhance Safety
Reduce the risk of overheating and electrical faults.
Boost Efficiency
Maintain low-resistance connections for better performance.
Increase Lifespan
Extend the life of critical components, reducing maintenance and replacement costs.
Health and Safety Considerations
When working with electrical jointing compounds like Unial, it’s important to prioritize health and safety. While Unial is highly effective in preventing galvanic corrosion, it contains substances that can be harmful if not handled correctly. This guide will help ensure that installers and project managers are aware of potential risks and follow best practices for safe usage.
Understanding the Risks
Unial jointing paste contains chemical components designed to provide a protective barrier against moisture and corrosion. Some of these substances may pose health risks if proper precautions are not taken. Key risks include:
Skin Irritation: Prolonged or repeated contact with the skin can cause irritation or dermatitis.
Eye Irritation: If the paste comes into contact with the eyes, it may cause redness, watering, or discomfort.
Respiratory Issues: Inhalation of fumes or particles, especially during application in confined spaces, can lead to irritation of the respiratory tract.
Environmental Impact: If improperly disposed of, the paste can harm the environment, particularly aquatic ecosystems.
Best Practices for Safe Handling
1. Personal Protective Equipment (PPE)
Always wear appropriate PPE when handling Unial to minimize exposure:
Gloves: Use chemical-resistant gloves to protect your hands from irritation.
Safety Glasses or Goggles: Protect your eyes from accidental splashes.
Respiratory Protection: In confined or poorly ventilated areas, use a mask or respirator to avoid inhaling fumes or particles.
2. Work in Well-Ventilated Areas
Ensure that you’re applying Unial in a space with adequate ventilation to prevent the buildup of fumes. If working indoors, use exhaust fans or open windows where possible.
3. Avoid Direct Contact
- Do not touch your face, especially your eyes, after handling Unial.
- Wash hands thoroughly with soap and water after use, even if gloves are worn.
4. Safe Storage
Store Unial in a cool, dry place, away from direct sunlight and sources of ignition. Ensure the container is tightly sealed when not in use to prevent leaks or spills.
First Aid Measures
If accidental exposure occurs, follow these first aid measures:
Skin Contact: Wash the affected area with soap and water. If irritation persists, seek medical advice.
Eye Contact: Rinse immediately with plenty of water for at least 15 minutes. Seek medical attention if irritation continues.
Inhalation: Move to fresh air immediately. If breathing difficulties occur, seek medical attention.
Ingestion: Do not induce vomiting. Rinse the mouth with water and seek immediate medical advice.
Safe Disposal Practices
Unial jointing paste contains substances that can be harmful to the environment if not disposed of properly:
Do not pour excess paste down drains or into waterways.
Dispose of unused paste and empty containers according to local regulations for hazardous waste.
Consult your local waste management authority for guidance on safe disposal.
Regulatory Compliance
Unial complies with Health and Safety regulations, including:
COSHH (Control of Substances Hazardous to Health)
REACH (Registration, Evaluation, Authorisation, and Restriction of Chemicals)
Always refer to the Safety Data Sheet (SDS) provided with the product for detailed information on handling, exposure limits, and emergency procedures.
Key Takeaways
Protect Yourself: Always wear PPE and avoid direct contact with the paste.
Work Safely: Ensure good ventilation and follow safe handling procedures.
Be Prepared: Know the first aid measures and keep the Safety Data Sheet readily available.
Dispose Responsibly: Follow local guidelines for hazardous waste disposal to protect the environment.
By following these guidelines, you can safely use Unial jointing paste while protecting yourself, your team, and the environment. For further information or to request the product’s Safety Data Sheet, contact us today.
Conclusion: The Proactive Choice
Galvanic corrosion can compromise even the most robust electrical systems, but it’s important to remember that it requires an electrolyte to occur. While this means that corrosion is not always a threat, the unpredictable nature of environmental exposure makes proactive protection essential.
Unial jointing paste provides a simple, effective safeguard, ensuring your connections remain efficient, safe, and durable, whether they’re in overhead lines, gland plates, or transformer connections.
Please remember though if a substance can achieve these things then it must be harmful. Indeed in the wrong hands and without assessment an employee or worker can suffer if correct application and PPE is not implemented. Ensure you or your personnel know the fact and act safely. If they do then the connection should be good for years to come.
Disclaimer:
The information provided on this site is for general informational purposes only and may not reflect the most current regulations or standards. Legislation, industry guidelines, and best practices can change over time, and it is the user’s responsibility to research and ensure compliance with the latest requirements for their specific situation. Always consult a qualified professional for advice tailored to your project or application.