We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is the Salt Spray Test?

By Vasanth S.
Updated May 17, 2024
Our promise to you
AboutMechanics is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At AboutMechanics, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

The salt spray test is an accelerated corrosion test conducted on materials and products to see how well they handle damage inflicted by salt. The material to be tested is usually placed into a chamber and a solution of sodium chloride is sprayed onto its surface. The test can help researchers and product designers develop paints, coatings, or film that is more resistant to salt damage. Salt damage is very rare for most types of products, however; the salt spray test is generally unreliable since it may not take into consideration many of the natural variables that cause corrosion.

A salt spray test is also known as the salt fog test. A sample is usually placed in a temperature controlled container and a 5% sodium chloride solution is dispersed onto it. The sample is wet throughout the test and the temperature is kept constant. The test duration can be anywhere between 24 hours and 1,000 hours. At regular intervals, the samples are rotated to allow even coating of the salt solution.

The result of the test is rusting of a surface. The number of hours until the first sign of rust is noticed is recorded. Other methods include recording the number of hours until 5% of the surface is rusted. The criteria differs among laboratories.

One of the best way to prevent rusting on steel is to coat the steel with zinc or aluminum. Galvanized steel is coated with zinc and generally lasts about 10 hours in the salt spray test. The best performing steel is typically coated with aluminum and zinc. It lasts about 50 hours before 5% of the surface is covered with rust.

This coating is important for applications that are exposed to the weather, such as roofing material. It is recommended that roofing material be coated with zinc before the paint layer is applied. This will reduce corrosion associated with rain or surf splash.

The salt spray test doesn't take into account the exposure to ultraviolet rays, which are primarily responsible for degrading painted materials. Another questionable aspect of the test is the fact that the sample is exposed to wet conditions continuously. This may not be the case for most products when they are actually used. The test also produces discrepancies between identical samples during testing. For example, one sample may take 5 hours for rust to form, while an identical sample may take 10 hours.

AboutMechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Discussion Comments

AboutMechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

AboutMechanics, in your inbox

Our latest articles, guides, and more, delivered daily.