Waiting to wash your car? Don’t | AspenTimes.com

Waiting to wash your car? Don’t

Scott Condon
Aspen Times Staff Writer

If you want to prevent magnesium chloride from rusting out your car you’re going to have to wash it when it makes the least sense, suggests a study conducted for the Colorado Department of Transportation.

The de-icer, commonly referred to as mag chloride, is most corrosive during wet conditions, says a study entitled “Corrosion Effects of Magnesium Chloride and Sodium Chloride on Automobile Components.”

Mag chloride has a high viscosity so, as every driver knows, it forms a thick goo on windshields, fenders, wheels and undercarriages. It also has a characteristic called “hydraphilicity” ” meaning it turns from crystalline to solution form during humid, wet conditions. That transformation “leads to high corrosion rate on the metals,” the study says.

So what does that mean to vehicle owners? They might have to alter their car cleaning patterns. Most people tend to wait out snowy and sloppy periods because their cars won’t stay clean. They want to wait until the roads dry out.

If roads take several days to dry out ” like after Aspen’s big storm on Jan. 2-3 ” vehicles are getting eaten up by mag chloride. The best strategy, the study indicates, is to continue to keep vehicles clean when the roads dry out but also bite the bullet and spend the money to wash them even while roads are sloppy. It’s a boon for car wash owners.

The CDOT study also found that sodium chloride, which is mixed in with sand in Colorado, is more corrosive than mag chloride in dry conditions. The study cites statistics that show road salts are inexpensive to use, at about $55 per ton. However, the treatment caused about $1,543 per ton worth of damage to vehicles, bridges and the environment.

The CDOT study was performed in response to complaints about mag chloride from trucking companies.

“Anecdotal information provided by Colorado trucking companies revealed widespread belief that magnesium chloride is responsible for excessive pitting and corrosion, increased vehicle maintenance and cleaning costs, accelerated metal component wear, breakdown of electrical systems, and increased safety risks due to loss of visibility, wet highways and affected brake systems,” the study says.

A survey of Colorado trucking companies showed that 72 percent of respondents noticed more wear on equipment since Colorado started using mag chloride. Twenty-eight percent reported no problems.

[Scott Condon’s e-mail address is scondon@aspentimes.com]