Wildfire ash damaging to vehicles

Wildfire ash could ruin your car’s paint job, but the last thing you want to do is just hose it off.

In its dry state, wood ash (potassium carbonate) is generally not much more than a messy inconvenience, but once mixed with dew, rain or water from the hose, ash becomes lye (sodium hydroxide), a caustic chemical that can eat through a car’s clear coat and permanently etch its paint. Lye is also dangerous for skin, and can cause chemical burns if left untreated.

To neutralize the chemical transformation of wood ash into lye, auto care experts like Greg Boes of National City and Crystal City Car Washes, which operates three car washes in the Bay Area, recommend that soap and water be used each time a car requires exterior cleaning. Windshield wipers should be wiped down with a wet rag before using, and changed completely before winter arrives.

Tiny specks of ash may look soft and powdery, but wood ash is actually full of abrasive particles. Brushing dry ash off of a vehicle is not recommended, as the abrasive particles within it can also scratch a car’s paint. Likewise, using wipers to clear windshields of ash can cause permanent damage, marring the windshield by etching its glass.

Once the wildfires of this fire season are contained, air filters in the engine and ventilation filters in the passenger compartment should be replaced. Dirty filters lower fuel economy and increase emissions, ultimately costing owners more to operate their vehicles in the long run.