Rust-Oleum CopperCoat Green Wood Preservative Review

By Mego Kimani •  Updated: 07/03/23 •  4 min read

Rust-Oleum CopperCoat Green Wood Preservative is an easy-to-use and highly effective timber preservative. It is a hydrocarbon and copper naphthenate solvent, best suited for below-ground use. Below is a detailed review of this product:

What Protection Does It Offer?

Rust-Oleum CopperCoat Green wood preservative provides wood protection against wood-damaging insects and the surface growth of fungal organisms. These protections are purposely designed to sustain the timber’s exterior, below or above ground use for a long period of time without damage.

The protections are largely made possible by the preservative’s formulation, which comprises a highly potent insecticide and almost two times the amount of fungicide found in other standard products. 

In specific, the preservative’s insecticide content protects timber from wood-damaging insects such as termites, ants, and powder post beetles. 

Inversely, its fungicide content offers protection against the surface growth of fungal organisms including mold, fungi, and mildew. As such, Rust-Oleum CopperCoat is also highly resistant to decay and rot, ensuring your below ground wood aptly withstands the test of time.


This preservative formulation allows for proper wood penetration for effective protection. However, the degree of penetration largely depends on your application process.

Ground Contact Use

For ground contact use, it is recommended to use the dip method application to ensure the chemical penetrates deep into the sapwood. This means immersing your wood in the liquid for 12 to 48 hours, depending on the nature of the wood. Once the preservative has completely penetrated the wood, air-dry the wood fully before installation.

Above Ground Use

For above-ground use. You should immerse the wood into the preservative for 3 to 10 minutes. Alternatively, use a paintbrush, spray, or roller to apply as many coats of the preservative as needed onto your wood. For optimal penetration, allow at least one to two hours in-between applications.

Wood Surface

Apart from the application method and type of wood, the nature of the wood’s surface will also determine the preservative’s level of penetration. Surface porosity is a key factor given that weathered or rough wood surfaces will absorb a higher amount than flat surfaces. Also, ensure the wood surface is free of debris, dust, or dirt, and is dry.


Noteworthy, Rust-Oleum CopperCoat Green Preservative reacts with wood cellulose to ensure minimum leaching. Therefore, if properly penetrated, you are assured that your timber will retain the preservative for a long.


It is estimated that around 5 gallons of this preservative will cover 1000 board feet of lumber using the dip application method. For brush, roller, or spray coating, one gallon can cover at least 150 square feet of lumber.

How Long Does Rust-Oleum Wood Preservative Last?

How Long Does Rust-Oleum Wood Preservative Last

Rust-Oleum CopperCoat Wood Preservative can last for at least 60 years. This significant longevity is premised on the fact that the preservative is made from copper naphthenate, a blend of copper salts and naphthenic acids. Compared to other standard wood preservative ingredients, naphthenic acids, which are petroleum refining by-products, have a higher efficacy against decay fungal organisms.

Side Effects


The primary side effect of this preservative is that it is highly corrosive. As such, it can cause irreversible skin or eye damage if one comes into contact with the chemical. In case of eye or skin contact, make sure to rinse the affected area with cold water for at least 20 minutes and seek medical help if severe.


Notably, Rust-Oleum CopperCoat Wood Preservative is also toxic to animals and human beings. Therefore, it should not be ingested, should not be disposed of in water bodies to protect aquatic invertebrates, and should be disposed of accordingly.

Can Rust-Oleum Wood Preservative Be Used in Vegetable Greenhouses?

Yes, Rust-Oleum Wood Preservative is safe for use in vegetable greenhouses and gardens. Its copper-based ingredient does not leach into the vegetation’s root system or into the soil. Therefore, there is no chance of human beings ingesting this poisonous ingredient through the planted vegetation.

Is It Worth It?

Rust-Oleum CopperCoat Wood Preservative is definitely worth every penny. It protects below-ground and above-ground wood from wood-burrowing insects, as well as fungal growth. What’s more, this protection is guaranteed to last for at least six decades, particularly due to its anti-leaching capabilities.

The only downside is its toxicity and corrosive nature, which requires you to be overly vigilant when using this preservative.

Other notable drawbacks include its foul odor and green color.

Recommended: Guide to treating ground contact lumber

Mego Kimani

Hi there, my name is Mego Kimani, and I am the owner of Woodmeter, a website dedicated to wood finishing. At Woodmeter, we offer a comprehensive resource for woodworkers and DIY enthusiasts, providing information on everything from achieving the perfect finish to product recommendations and technique guides. Our goal is to empower our community with the knowledge they need to create beautiful, long-lasting finishes on their projects, no matter their skill level or experience.