An increasingly corrosive environment for all vehicles
For more than 50 years, the compound sodium chloride has been used for deicing roadways in winter conditions. Its use is diminishing, however, as magnesium chloride and calcium chloride have become popular options due to ease and speed of application, among other benefits.

As ice management chemicals change, so do the corrosion effects on equipment. The frequency of corrosion has also increased, and the repercussions on design details such as dissimilar metal contact, the potential for liquid accumulation, exposed metals, and electrical connections has become much more significant.

The downsides to magnesium chloride and calcium chloride as deicing agents are varied and serious in terms of the potential increase in maintenance time and costs. State and local DOTs may apply these chemicals prior to any snowfall, increasing the likelihood and degree of exposure to cars, trucks, and trailers. These materials are especially destructive because of their ability to cling to the underbody of a vehicle and re-crystallize as they slowly dry out. By nature they attract and absorb moisture from the surrounding environment, keeping them in a semi-solution state for extended periods of time, which multiplies their corrosiveness.

Process of corrosion
It is important to understand that moisture, road debris, winter road traction and deicing materials also create a "sandblast" effect on vehicles, which primarily affects the understructure area. Once the protective coatings are abraded, even if only to a minor degree, these areas are exposed to the caustic environment caused by road chemicals. Additionally, dirt, debris, and moisture will continue to accumulate on these compromised surfaces. If not maintained or repaired, persistent deterioration and oxidation of the host surface results, the most visible evidence of the damage being red rust.

Results of corrosion
Over the past 15 years, it is estimated that the costs associated with corrosion caused by anti-icing chemicals have increased more than tenfold. A University of Idaho study in 2004 revealed that the U.S. transportation industry spends more than $23 billion annually.

To any company hauling freight, this equates to unprecedented costs for repair and replacement attributed to corrosion, trapped moisture and rust and the potential premature retirement of equipment. In terms of trailers, road chemicals may affect a variety of components: structural members, suspensions, support gear, and top and bottom rails, to name a few.

Prevention and maintenance for trailers
Corrosive effects are particularly prevalent in northern states and Canada, but they can be found in anywhere acid rain exists. Since corrosion forms at spots where gravel, stones, etc. have penetrated protective coatings it is important to keep the these barriers in place.

Proper maintenance of equipment is crucial for optimum corrosion protection. Two simple preventive maintenance steps can help avoid major repairs of a trailer in the long run.

1. Frequent pressure washing with a properly mixed ratio of fresh water and soap, especially in the undercarriage area, helps remove corrosive chemicals used for deicing. Cleaning procedures should include a low to mild pressure application to ensure against lifting fresh/new coatings at abraded areas as well as thorough rinsing.



2. Repair any damaged areas of the coating as soon as possible to prevent spot corrosion that can spread.

Great Dane performance undercoating compounds and other solutions

Great Dane undercoating compounds are specifically designed to provide a protective barrier against harsh environments. "Dry-Flex" undercoat is a soft and flexible high build film that resists stone chipping and temperature extremes while blocking moisture from reaching vulnerable components of the underbody.

Underbody "I" Beam crossmembers are dipped in a specially formulated high temperature hot melt wax compound that completely encapsulates the crossmember. This effectively blocks corrosion by sealing the steel from the environment.

Great Dane's partnership with its vendors to develop exciting new technologies to further enhance underbody corrosion control is ongoing. Thermo-plastic coating of steel underbody components is currently in testing, and advanced chemistry for soft coatings is under continuous development.