Signs of Rust And What Causes Them

Posted on May 1, 2023 in Auto Repair, Maintenance

If your car is starting to show signs of rust, you’re probably not happy about it. Rust is one of the pesky but inevitable problems that come with owning a vehicle.  In this article, we’ll discuss the common signs of rust and what causes them.

Types of Rust

Rust is the layman's term "oxidation," or the breakdown of iron-based metals. Given enough time and exposure to the elements, most types of iron and steel will completely reduce to iron oxide through the rusting process. Since these metals are commonly used in cars, there are three main types of rust for drivers to be concerned about:

1) Surface Rust

The first signs of surface rust usually appear in the paint. This type of rust preys on small nicks, cracks, and scratches. As the clear coat wears, your paint also becomes vulnerable to wear and abrasions. Once water penetrates the unprotected metal, it oxidizes. Pure iron and aluminum don't oxidize as aggressively but steal tends to have impurities in the metal that accelerate the rusting process.

2) Scale Rust

Exposed steel rusts at different rates depending on a few variables: alloy components, thickness, the environment the steel is in, and the type of heat treating the steel undergoes. Scale refers to the oxides of iron that are formed on wrought, or worked, metals as a result of mill operations (usually from high temperature rolling or furnace treatment). These chemical processes corrupt the surface and reduce the metal’s strength, making it more vulnerable to oxidation. Over time, water can react to the chemicals used in a heat treatment creating scale rust. The scale is usually hard but brittle and flaky.

3) Penetrating Rust

After prolonged exposure to the elements, oxidized steel will typically degrade to brittle iron oxide causing holes to form in the metal sheets. Automakers do a lot to try to prevent this severe type of corrosion, and many vehicles now have a thick coating on the underside that will chemically seal the steel against oxidizing agents. But those dips and coatings wear off over time, especially on the roadside of the vehicle where salt and other elements cause excessive wear on the metal. Penetrating rust can usually be prevented if it’s caught and treated early enough.

Uncover Signs of Rust With The Experts At V&F

If left unchecked, a rust spot can quickly grow until it causes a structural problem. In many states, a car with rust holes in the body won’t pass inspection, regardless of where the spots are located or how serious they are. Since 1988, our family-owned and operated service center has been providing top-quality auto repair services to Agawam, Feeding Hills, Southwick, West Springfield, and the surrounding Massachusetts communities. If your car needs maintenance or repair this winter season, call us at (413)314-2280 or schedule an appointment online. This article was originally published in March 2018 and has been updated regularly.