Brine used for winter road safety has taken a toll on vehicles
The use of brine solutions to remove snow and ice from roadways has proven even more effective and more economical than rock salt, but for all motorists this has come at an increased cost.
That's because brine — a liquefied compound with about 23 percent salt content — can be even more corrosive than its dry alternative to a car or truck's exhaust system, gas tank and other undercarriage components, according to a new report from the American Automobile Association.
Engineering experts with AAA have concluded these road-clearing materials have cost U.S. drivers an estimated $15.4 billion in rust repairs over the last five years, or approximately $3 billion annually.
The average fix for motorists costs $500, the report concluded.
"While the application of de-icing salts and solutions is critical to keeping our nation's roadways safe every winter, it's important that drivers pay attention to warning signs that their vehicle may be suffering from rust-related damage," said John Nielsen, AAA's managing director of automotive engineering and repair.
"This can be much more than a cosmetic issue; it can also create serious safety issues for drivers by impacting brake lines, exhaust systems, fuel tanks and electrical connections." Brine is a mix of rock salt (sodium chloride) and magnesium chloride, dissolved in water so they can be sprayed on the road.
"That's a very important point, because magnesium chloride is much more corrosive than sodium chloride, the rock salt," said Bob Baboian, an auto industry consultant and a fellow at the National Association of Corrosion Engineers.
Car rust and corrosion are caused by acid created when a salt is dissolved by the moisture in the air. Rock salt remains a crystal until the humidity reaches 70 percent, which doesn't happen much during the winter.
But magnesium chloride dissolves when there is only about 20 to 30 percent humidity. "Which means that your vehicle, if magnesium chloride is sprayed on it, is wet constantly," Baboian said. The acid stays on your car and slowly eats away at the paint and metal, he said.
AAA said the corrosion can be made even worse by placing the vehicle in a warm garage; this allows that sticky compound on the metal to remain in liquid form even longer.
The other dilemma is as a liquid, brine can more easy find its way into the crevices of a vehicle.
While the damage and the costs to repair them are indisputable, studies remain inconclusive on whether rust damage from New England winters is inevitable — whatever product is used to clear the roads.
Richard Bilodeau is the city of Manchester's fleet supervisor of maintenance. He believes damage to vehicles from brine can be just as well-contained as from rock salt.
"I can tell you my brine truck is getting to be 15 years and it's still going strong," Bilodeau said. "Every time our vehicles, cars or trucks, go out on a run and we bring them back, they get a thorough cleaning; that's the key during this time of year."
Car washes should only be done once the weather is warmer to prevent freezing door locks, Bilodeau said.
AAA advises caution with powerful washes; a forceful blast can drive salt and other chemicals farther into a car's cracks and crevices.
Using a car wash detergent with a low pH level can help put a stop to salt's corrosive effects.
Bilodeau also said motorists should consider a rubberized treatment such as one 3M makes which reduces how much the brine sticks underneath the car. A waxing of the chassis prior to winter can also help prevent brine from collecting on it, he said.
Cars and trucks are being made with better anti-corrosive metals, he pointed out.
"We are in the middle of ordering some new fleet cars and the undercarriages will all be stainless steel because frankly that's the way to go in the future in this climate," Bilodeau said.
But Robert Sculley begs to differ. He's the longtime president of the New Hampshire Motor Transport Association and his member truckers say soon after brine was first introduced here on Interstate 93 near the Massachusetts border, they reported much more damage.
"I can't speak from the science of it but my members tell me there's no question that the brine is more corrosive than rock salt ever thought of being," Sculley said. "It eats at the suspension, the frame and then also gets into the electrical components which can really cause some big-time damage and costly repairs."
Call to ban brine
A Merrimack resident, Sculley also heads the trucking lobby in Vermont.
"This has been an even bigger issue up in Vermont in part I believe because brine has been even more prevalent in that state than it has been here," Sculley said.
The Motor Transportation Association of Connecticut has asked that state to ban the salt solutions, arguing their trucks have seen an increase in corrosion damage of all sorts — in brake shoes, brake valves, coil springs, frame rails, radiators and the like.
As in New Hampshire, Connecticut's DOT increased its reliance on brine starting in 2006.
Connecticut lawmakers discussed last fall a bill to require the state to come up with a "natural alternative" to brine.
But a 2015 Connecticut Academy of Science and Engineering report contends no such alternatives exist that are as cost-effective and efficient as these liquid deicers.
In its report, the group concluded there were fewer crashes in the years brine was used in Connecticut versus rock salt and sand.