Mag Chloride And Your Paint: A Colorado Winter Guide

Colorado does not treat roads the way the Midwest does. Instead of rock salt, crews spray magnesium chloride brine, and mag chloride behaves differently on your paint. It pulls moisture out of the air, so it stays damp on the panel and keeps working long after the road looks dry.

Why brine is harder on a car than dry salt

Dry salt sits on the surface and blows off. Brine bonds to it. It creeps into wheel barrels, the underbody, the lower rockers and the seams behind the bumper, and it holds water against bare metal and clear coat. On trim and unsealed wheels it leaves a white haze that gets harder to remove the longer it sits.

How often to wash in the winter

When crews are actively spraying, every two weeks is the honest answer. What matters more than frequency is what gets cleaned. A quick top down rinse leaves the parts that rust. Wheels, wheel wells and the underbody are where brine does damage, so those have to be part of the wash. Our Exterior Detail is $79 and takes about thirty minutes, wheels and tires included.

What keeps it off the paint

Protection makes brine easier to remove instead of stopping it entirely. A wax or sealant is a $40 add on and lasts a few months, which covers one season. A ceramic coating starts at $399, includes decontamination, and holds for years, so winter grime rinses off instead of bonding. Either way the goal is the same: give the brine a slick surface to sit on rather than bare clear coat.

What to do when spring hits

By March most vehicles here are wearing a film that a wash will not fully remove. A clay bar treatment for $30 pulls off bonded contamination and makes the paint feel like glass again. If the finish is dull or marked with swirls under the film, that is paint correction, which starts at $599 with a full decontamination.

See our full services page and our Longmont city page for more.