For professionals involved in engine overhaul, copper spray is one of the topics that can spark debate. Copper spray used to be valued for its properties primarily in motorsports and in the maintenance of older vehicles. But is this familiar ‘tool’ still relevant in the context of modern engines? In this article, we explain when copper spray can be used and why it is sometimes not the best choice.

What is copper spray?

'Copper spray' can refer to two different products. The first is a copper-based grease used for high-temperature lubrication. The second, often called 'Copper Spray-A-Gasket,' is a copper-based adhesive designed to improve the sealing and assembly of gaskets.

Traditionally, copper sprays were popular when Gaskets did not have coatings, for example in motorsports and older vehicles. The benefits included better heat transfer, better sealing and easier gasket assembly during installation.

Why copper spray should not be used for cylinder head gaskets

Despite its historical value, copper spray should not be used on modern cylinder head gaskets. Manufacturers such as Elring explicitly advise against it. Today's Multi-Layered-Steel (MLS) Gaskets are designed for dry installation and feature coatings tailored to specific engine requirements. Adding copper spray interferes with the effect of these coatings.

Technical reasons to avoid copper spray on head gaskets

Gaskets made of pure copper in old or special engines can still benefit from copper spray. However, this is a rare and specialized use. In general, copper spray should not be used on head gaskets for the following reasons.

Change in tightening torque and pressure

Copper spray can affect load and tightening torque, causing the seal to be improperly adjusted.

Change in coating and thickness

Modern gaskets have specialized surfaces that do not benefit from additional layers. Copper spray can degrade the layer and change its thickness, affecting the effects of the coating and gasket.

Chemical reactions

Copper sprays can have a negative reaction to the gasket material and corrode it.

Appropriate use of copper spray

Although not suitable for head gaskets, copper spray or copper glue spray remains useful for paper gaskets, such as those on water pumps or oil pans. Here, a light spray helps hold the gasket in place and improve the seal.

Although liquid gaskets are a common alternative to these types of gaskets, they are often over-applied. This can lead to leaks or internal contamination. Copper spray, on the other hand, forms a thin and even layer, minimizing the risk.

Elring cylinder head gaskets: Designed for dry installation

Elring is a world leader in gasket technology. Its cylinder head gaskets are designed for dry installation, like with advanced materials such as Metaloflex® and Metaloseal®. These OEM-quality products do not require additional sealants such as copper spray and can be dangerous. With more than 100 years of sealing expertise, Elring provides reliable, OE-quality gaskets.

For modern engines, rely on precision products like Elring gaskets. Visit our webshop to explore the full Elring range and get expert, tailored advice.

Click here for Elring's full range of products

Conclusion: Use copper spray wisely

Copper spray still has good applications in today's workshops, but not on cylinder heads. For cylinder heads, follow the manufacturer's guidelines for optimum engine performance and reliability. A detailed manual for cylinder head gaskets is also available on the Wilmink Engine Parts website.

Click here for the step-by-step guide