A GUIDE TO Rustproofing

Rust, tinworm, corrosion; whatever you like to call it, the dreaded brown crumbly stuff has shortened the life of many a vehicle. And it’s not just steel panels that can corrode. Copper brake pipes turn green with copper oxide, while aluminium develops a white flaky exterior finish. However, the worst is steel, which turns into the crumbly iron oxide that we dread to discover bubbling up underneath the paintwork of an exterior panel or spreading through sills and wheelarches.

There are numerous methods for helping to prevent the spread of corrosion through a vehicle, so we’ve outlined the popular ones over the following pages and the best methods we’ve found for keeping rust under control. There’s no easy method and once rust has taken hold, it’s hard to keep away, especially if you use a vehicle every day.

Whilst it’s important to know how to protect a vehicle from corrosion, it’s perhaps just as important to understand how rust forms. For corrosion to occur, especially in steel, it’s worthwhile knowing what steel is and how this alloy is made.

To make steel, iron ore is extracted from the ground, smelted in a blast furnace where impurities are removed, but a small quantity of carbon (usually less than 1%) is added to make the iron less brittle so that it can be bent and shaped.

Knowing what needs to be present for corrosion to occur is the next stage towards understanding the rusting process. Water and oxygen are the two ingredients. However, for the steel to turn into rust (iron oxide), the iron in the steel needs another element to help with the reaction. This could be the carbon that is contained in the steel, or another metal such as aluminium.

Let’s assume there’s an aluminium panel next to a steel panel on a vehicle. With water and oxygen present, which could