Electronic rust protection kits for cars - does this device work?
What is electronic rust protection?
Electronic rust protection kits claim to use cathodic protection to send electrons through the metal on a car and bring it to a state where it is immune from corrosion. This would work well in theory, but there are some problems that we'll have to discuss. Some people swear by these things on their car, and they do work well on some applications like pipelines and boats.
We'll start with the simple stuff: what makes cars different from pipelines and boats?
A car is not a boat
Underwater pipelines and boats have one thing in common: they are surrounded by water. Unless your car has run off the road and into a lake, it's not surrounded by water. Why does this matter? Well, for cathodic protection to work, there needs to be a closed circuit to return the electrons that are being sent out by the device. With water surrounding the circuit, there is an abundance of free electrons so it's easy for the circuit to complete. It's not so easy on a car surrounded by air.
If electronic rust protection is a gimmick, why do people still buy them?
Although the science seems to indicate that electronic rust protection devices like RustStop shouldn't work on cars, people still buy them and many people still claim they work. What's going on here? Well, the problem is that people who buy these kits and spend money to have them installed probably care a whole lot more about preventing rust than the average car owner. That's not a bad thing, because rust is like cancer to a car, but it also means that they don't usually just rely on electronic rust protection to prevent rust. So if their 15-year-old car looks better and more rust-free than yours, that doesn't mean electronic rust protection works.
Should I buy electronic rust protection?
I would not advise buying one of these kits at this time. If you want to prevent rust, wash your car regularly, wax it several times a year, and make sure to keep the underside clean. Also repair all paint scratches and chips immediately.