Truck Topics

Combating Corrosion

However, the trucking industry has discovered these chemicals are far more damaging than old-fashioned road salt when it comes to rust and corrosion on vehicles.

 

The colored film on the windows is just the latest development. Roy Gambrell, who is heading up a new Corrosion Action Committee for the Technology and Maintenance Council of the American Trucking Associations, explained that these de-icers can apparently be a bit slippery when applied to the roads before the precipitation starts coming down. After a resulting fatal crash last winter, a number of states started adding dye to the de-icers to alert motorists that it had been applied to the roads.

 

It's not easy to get off; regular windshield wiper fluid won't do it. Gambrell says some drivers have found that a water repellant product such as Rain-X helps keep the stuff from sticking as bad.  Phosphoric acid, he says, is the cleaner of choice of many drivers – shake it up so it sprays out of the container, douse the windshield with it, and wipe off (don't forget to then use plain water to clean off the soda syrup afterwards). It's probably the phosphoric acid Coke uses.

 

The problems with the dye serve to illustrate how tenacious these de-icing chemicals are. You can't just spray them off with water; equipment needs to be cleaned with a brush. And high-pressure washing could just push the corrosive chemicals deeper into crevices.

 

In turns out that some of the things that make mag chloride and calcium chloride so good at keeping roads clear are the same things that make them so destructive.

 

For one thing, calcium and magnesium chloride are highly soluble in water, so they produce a finer mist of spray under the vehicle than old-fashioned rock salt does. Because this spray is finer, it starts penetrating into areas where you wouldn't necessarily think it can get to – underneath the paint, inside the brakes, into the wiring, even the air brake system. It also sprays up higher on the truck. It attacks frame rails, crossmembers, suspension components, air tanks, fuel tanks, battery boxes, brackets, brake shoes, electrical systems, air conditioning condensers, radiators, metal coolant tubing, steel wheels, even inside the floor of the cab.

 

In addition, both these chemicals are hygroscopic, which mean they will absorb moisture from any source. If you put a chunk of dry magnesium or calcium chloride on a table in a laboratory environment and leave it overnight, when you come back, it will have a puddle of water around it that it has absorbed from the air.

 

This means that even when the weather and your equipment are dry, the chemicals continue to attract moisture. They easily mix with the water they attract and then seep into the tiniest cracks.

 

It's unlikely that highway departments will stop using something that has proven to be such an effective lifesaver, so manufacturers are working on developing more corrosion-resistant products and truck owners are developing strategies to prevent and deal with the de-icers' damage.

 

The electrical system is particularly vulnerable, and with increasing use of electronics on vehicles, it's more critical than ever to keep corrosion at bay. As the electrical system is powered and unpowered, and wires heat up, they expand. When they contract, they draw in the air around them – and contaminants and moisture.

 

Phillips Industries offers 10 tips to protect your electrical system:

* Use heavy-duty, adhesive-lined heat shrink tubing on all electrical connections.

*   Protect battery posts and terminals with anti-corrosive spray.

* Make sure grounds lead directly to the batteries’ negative posts. Grounding to the chassis or engine will lead to corrosion, poor contacts and faulty electrical operations.

* Store electrical and air coils in stowage devices designed for this purpose when not in use for extended periods of time.

* Swap plug ends on the J560 tractor-to-trailer cord every six months. This will even out plug wear.

* Never puncture a hole in wire jacketing, because it will allow the damaging chemicals to wick into wires. Instead, when tracing down circuits, work from the metal connectors.

* Remove build-ups of salt, especially magnesium chloride and calcium chloride, by frequently brush-washing equipment during cold weather. Do not power wash, because water can be forced into areas from which it can’t escape.

* After every cleaning, re-apply dielectric grease on plugs and socket pins.

* Clean connectors with a plug-and-socket brush and water (not soap) every six months.

* Specify sealed wiring harnesses and other components designed to guard against corrosion.

 

Beyond the electrical system, washing vehicles to try to keep the chemicals off the metal is important. However, keep in mind that more cleaning liquid is not necessarily better – in some cases, an over-concentration of washing compound may actually attack some of the plastics that are there to provide corrosion resistance.