Galvanized vs Painted Steel: Key Differences

Galvanized steel gets its strength from a tough zinc coating that shields it from rust, while painted steel relies on layers of paint for protection and style.

Choosing between galvanized and painted steel can seem simple, but the differences go beyond just appearance. 

In this article, we’ll break down how each material stands up in terms of resistance, durability, application, and overall performance, so you can make the best decision for your project.

Different Materials of Galvanized vs Painted Steel

Steel Material

Galvanized steel is often made from lower-carbon steel. Because it bonds well with zinc during the galvanizing process, ensuring strong corrosion resistance.

In contrast, painted steel can be made from a wider variety of steel types, including both carbon and alloy steels, depending on the application. 

Coating

Galvanized steel is protected by a zinc coating. It is applied using methods such as hot-dip galvanizing.

Painted steel uses a variety of paints depending on the desired finish and application, such as epoxy paints, polyurethane paints, and powder coatings.

Different Properties of Galvanized vs Painted Steel

Coating Thickness

Galvanized steel has a thicker layer than painted steel. The zinc coating on galvanized steel typically ranges from 20 to 100 µm, depending on the process and steel grade. 

In comparison, the paint layer on painted steel is usually thinner, around 20 to 40 µm. This means galvanized steel offers a more substantial protective barrier compared to the paint coating on steel.

Corrosion Resistance

Galvanized steel has better corrosion resistance. Its zinc coating can protect the steel from rust. Even if the coating is scratched or damaged, the zinc corrodes first, shielding the steel from rust. This built-in defense mechanism is known as galvanic protection. 

Painted steel depends solely on the paint to create a barrier. Once the paint cracks, moisture can reach the steel. 

Durability

Galvanized steel offers stronger durability than painted steel. The zinc coating is tough and resistant to wear, providing long-lasting protection. Over time, the zinc slowly corrodes, but it still protects the steel underneath for many years.

Painted steel relies on the paint layer, which can chip, peel, or fade with exposure to the elements. Once the paint is damaged, the steel is more prone to rust and wear.

• How long does galvanized steel last?

The zinc layer can last from 20 to 50 years, depending on the environment and coating types.

• How long will painted steel last?

The paint typically lasts around 5 to 7 years, depending on the quality of the paint and the environment.

Coating Color

Galvanized steel usually has a dull gray or silver color due to the zinc coating, and this color cannot be easily changed. In contrast, painted steel offers much more flexibility in appearance. It can be coated in different colors and finishes for custom design needs. 

Cost

Galvanized steel is typically more expensive upfront than painted steel due to the cost of the zinc coating process. However, as the Z coating lasts longer and requires less maintenance, the overall lifetime cost can be lower.

Painted steel is usually cheaper to produce initially, but the need for repainting and repairs over time can increase long-term expenses. 

How to Choose Between Galvanized and Painted Steel

Choosing between galvanized and painted steel depends largely on where and how it will be used. 

• If you’re working on an outdoor structure exposed to the elements, like a fence or roof, galvanized steel is ideal because it offers long-lasting protection against rust.
• For indoor projects like furniture, shelving, or decorative elements where appearance matters more, painted steel offers more color and finish options to match your design preferences.
• If you prefer low-maintenance materials, galvanized steel requires less upkeep over time. Painted steel may need periodic repainting, especially in environments where the paint could chip or fade.

Can You Paint over Galvanized Steel?

Yes, you can paint over galvanized steel, but it needs proper preparation. The surface must be cleaned to remove any oils or contaminants, and a primer designed for galvanized metal should be applied to help the paint stick. Without this preparation, the paint may peel or not adhere properly.

Get a Custom Quote for Your Steel Needs

If you’re looking for high-quality steel for your next project, Steel Pro Group offers competitive prices on both galvanized and painted steel. Please visit our website or contact us today for a quote tailored to your needs!