EMT Conduit and Rust

EMT conduit, short for Electrical Metallic Tubing, is a thin-walled tubing used to protect electrical wiring. It is commonly made from galvanized steel or aluminum. While galvanized steel EMT conduit can resist rust for a period of time, it is not immune to rusting eventually. Rust is more likely to occur at the cut ends or scratched surfaces of the conduit.

Factors Contributing to Rust on EMT Conduit

Material

EMT conduit is typically made of galvanized steel or aluminum. Galvanized steel EMT conduit will resist rust for a few years, but it is inevitable that it will eventually rust. Aluminum EMT conduit, on the other hand, is naturally rust and corrosion resistant without additional treatment.

Protective Coating

EMT conduit is often coated with a protective layer to shield it from rust. However, this coating can degrade over time due to exposure to various weather conditions, such as rain and snow.

Wear and Tear

EMT conduit can experience wear and tear during installation and use, which can compromise the protective coating and make it more susceptible to rust.

Cutting and Scratching

Cutting and scratching the EMT conduit can remove the protective coating, creating entry points for rust.

Preventive Measures for Rust on EMT Conduit

Use Complete Coated Conduit

When selecting EMT conduit, ensure that it is fully coated and free from any scratches or signs of wear.

Avoid Cutting and Scratching

If cutting is necessary, use the appropriate tools and techniques to minimize damage to the protective coating. Avoid scratching the conduit during installation or handling.

Paint the Conduit

Applying a coat of paint to the EMT conduit can provide an additional layer of protection against rust, especially in harsh environments.

Tape the Conduit

Special adhesive tapes designed to prevent rust can be wrapped around the EMT conduit for added protection.

Consider Installation Location

Choose an installation location that minimizes exposure to moisture and other corrosive elements.

Fixing Rust on EMT Conduit

If rust does occur on the EMT conduit, there are several methods to address it:

Scrubbing

Rust can be removed from the surface of the conduit using sandpaper or an abrasive sponge.

Painting

Painting the rusted area with an appropriate paint can help prevent further rusting and restore the appearance of the conduit.

Replacing the Rusted Portion

If the rust is extensive or has compromised the structural integrity of the conduit, it may be necessary to replace the affected portion.

Conclusion

EMT conduit, whether made of galvanized steel or aluminum, can be susceptible to rust under certain conditions. To prevent rust, proper selection, installation, and maintenance are crucial. Regular inspection and timely intervention can help extend the lifespan of the EMT conduit and ensure the safety and reliability of the electrical system.

References

1. Will galvanized metal conduit balusters resist rust? – Home Improvement Stack Exchange
2. EMT Conduit | American Conduit
3. Does EMT Conduit Rust? | Doesit Rust

FAQs

1. Question: Is EMT conduit susceptible to rust when used outdoors?

Yes, EMT conduit, whether made of galvanized steel or aluminum, can rust when exposed to outdoor elements. However, aluminum EMT conduit is naturally more resistant to rust and corrosion compared to galvanized steel.

2. Question: What factors contribute to rusting of EMT conduit outdoors?

Factors that can contribute to rusting of EMT conduit outdoors include moisture, humidity, exposure to corrosive substances, and damage to the protective coating due to cutting, scratching, or wear and tear.

3. Question: How can I prevent rust on EMT conduit installed outdoors?

To prevent rust on EMT conduit installed outdoors, consider the following measures:

• Use aluminum EMT conduit instead of galvanized steel.
• Apply a protective coating or paint to the conduit.
• Avoid cutting and scratching the conduit during installation and use.
• Install the conduit in a location that minimizes exposure to moisture and corrosive elements.

4. Question: What should I do if rust occurs on EMT conduit outdoors?

If rust occurs on EMT conduit outdoors, you can take the following steps:

• Remove the rust using sandpaper or an abrasive sponge.
• Apply a rust-resistant paint to the affected area.
• Consider replacing the rusted portion of the conduit if the rust is extensive or has compromised the structural integrity of the conduit.

5. Question: Is there a specific type of EMT conduit that is more resistant to rust?

Aluminum EMT conduit is more resistant to rust compared to galvanized steel EMT conduit due to its natural corrosion-resistant properties.

6. Question: How long does EMT conduit typically last outdoors before rusting?

The lifespan of EMT conduit outdoors can vary depending on the type of conduit, the environment it is exposed to, and the maintenance it receives. Galvanized steel EMT conduit may last for several years before rusting, while aluminum EMT conduit can last significantly longer.

7. Question: Can I use regular paint to protect EMT conduit from rust?

While regular paint can provide some protection against rust, it is recommended to use a specialized rust-resistant paint or coating designed for metal surfaces. These paints typically offer better adhesion and durability, providing longer-lasting protection against rust.

8. Question: Is it necessary to replace rusted EMT conduit immediately?

The necessity of replacing rusted EMT conduit depends on the extent of the rust and its impact on the structural integrity of the conduit. If the rust is superficial and does not compromise the conduit’s functionality, you may be able to remove the rust and apply a protective coating. However, if the rust is extensive or has weakened the conduit, it is advisable to replace the affected portion or the entire conduit to ensure safety and reliability.