Road salt is one of the worst substances a vehicle body can be exposed to, and it’s also unavoidable in most of the United States. The more you drive in snow and ice, the greater your truck’s exposure to road salt. This makes it even more important to prevent corrosion from setting in and to protect against its spread in any rusting areas. Professional drivers in cold climates wind up putting more miles on their work vehicles than just about anyone, and since those vehicles represent your livelihood, protecting your truck is protecting your business.
Luckily, it’s not hard to protect your vehicle against road salt, but you do need to know where your truck is most vulnerable. When there’s a salt damage undercarriage problem, it doesn’t just affect your truck’s body. It also affects important systems like your brake lines, suspension, and fuel lines.
Effects of Road Salt on Vehicles
When iron or steel is exposed to moisture over a long enough period of time, it oxidizes. The result is the rust you’re familiar with seeing on older vehicles. Most metals oxidize in one way or another, but classic rust is unique to iron and iron alloys because it is a unique compound made up of the oxygen from the water and the iron in the metal. Since most trucks use steel in undercarriage parts, fuel lines, and other vital systems, rust is a hazard.
So why is salt dangerous? For starters, it keeps water from freezing at the regular temperature, exposing the undercarriage to moisture even when temperatures are below freezing. That extra exposure alone speeds up the oxidization, but the real issue is still the dissolved salt in the water.
When salt dissolves in water, it ionizes, meaning it becomes slightly negatively charged, and the oxygen becomes slightly positively charged. This is why salt water conducts electricity better than fresh water. Ionized suspensions like this are neutral across the whole substance, but at the molecular level, they are a mishmash of positive and negative charges.
Since iron conducts electricity especially well and forms ionic molecular bonds easily, this leads to a much faster rusting process than when a vehicle is exposed to fresh water. In areas like the undercarriage that typically go unpainted, there isn’t any protection against that increased corrosion.
How To Get it Off
Regular washing with fresh water is the best way to protect your undercarriage, no matter what type of vehicle you drive. This can expose the metal parts to moisture, but there’s a net benefit to rinsing away any salt that could speed up the corrosion. Drying the undercarriage after washing it is a great way to reduce moisture exposure, but it doesn’t prevent salt from coming into contact with the metal once you’re back on the road. For a more complete cleanse, there are cleaning supplies for semis that target salt deposits, making it easier to fully clean them off your truck.
You can wash the undercarriage yourself if you have an indoor garage and a hose, but there are also automatic car washes that can accommodate semis if you look for them. Just be careful to avoid any that use recycled water, but the salt that remains from previous vehicles can potentially damage your undercarriage.
How To Prevent It
Once you know how to neutralize road salt on car undercarriages, the best way to prevent salt buildup in the first place is to put a barrier between the metal that makes up your undercarriage and the salt in the water. Expensive undercarriage treatments accomplish this with a long-lasting seal, but you can add temporary protection with a good undercarriage wax.
For the best protection, get your undercarriage professionally treated every three years and use the wax to protect the sealant. The best wax for sealant protection is formulated specifically for your undercarriage, so look for the wax that is made to do this job if you want the best possible results.