Effects of ash on automotive paint/trim in Pacific Northwest

[Mr_Anderson]

It depends on what is burning and what is in the air. If it is a forest fire, I don’t think that any of the burned organic matter would cause any harm to the paint. Harmful ash usually comes from acidic material in the air like a volcanic eruption or coal exhaust. Anybody who has worked at a coal burning power plant can tell you what coal ash can do to a car’s paint. It makes it disappear. Burning coal releases sulphur dioxide. When mixed with rain you get sulphuric acid otherwise known as acid rain.
I would equate your situation to fireplace ash and when mixed with water it creates a base. It is not as harsh as household lye (pH value of 14), but it can be alkaline (pH value of 12). Just as a comparison, undiluted Megs D101 has a pH value of 13. My advice would be hose it off as soon as you can.

Sounds good. Thanks for the input, and info on different ash types. It all washed off nicely. The interior still smells like smoke, but I haven't had a chance to rent a carpet shampooer yet. Just vacuuming and wiping everything down didn't get rid of the smoke odor.

The only extra steps I took were to re-wash all of my wash mitts, micro-fiber towels and actually wash, rather than just rinse out the buckets. Where I live is only about a mile away from the road demarcating the boundary between a mandatory evac area, and a get ready to evac area. I still am finding ash in places that surprise me. Everything still smells like smoke, too.

I've not lived so near to a wildfire before. It smelled different than a wood stove, or camp fire. It left a horrible metallic taste in my mouth (for DAYS) as well.

[bcwang]

I'm not sure if it was related to ash, but I have a 2018 yaris which has a headlight where the top has lost it's coating in a pattern that looks like how water would sit on it if it rained. I'm in norcal so had that ash on it for a month where I didn't wash it since it was terrible air all the time to even be outside. For a 2 year old car to start having headlight coating dissolve vanish already, I'm thinking the ash and overnight dew over the course of time had did a number to it. Also, opticoat pro plus applied only 6 months before stopped beading on all horizontal surfaces, which was restored only after carpro reset. ONR did not clean it well enough to restore beading and things just stayed flat.

So that ash really does a number, now I know to get that stuff off asap. I hope Toyota would warranty premature headlight coating failure after only 2 years.