For vehicles:
Remove ash from your vehicle as soon as it is safe to do so. Prolonged exposure to volcanic ash and dust can damage the paint and glass.
Carefully wash the ash from your vehicle with a stream of water from a garden hose. Volcanic ash is very abrasive and can easily scratch your vehicle.
Never wipe, brush or mop the ash or dust that accumulates on your vehicle or windows.
Avoid prolonged driving in airborne or accumulated volcanic ash. Volcanic ash or dust can cause severe damage to your engine.
If your vehicle is exposed to volcanic ash, change your air filter and have your vehicle checked by a qualified auto mechanic as soon as possible.
Avoid using windshield wipers if at all possible as glass scratching may occur. Replace any windshield wiper blades that are damaged from the effects of the fallout.
in short, i wouldn't be 'blasting' the ash off... 'sheet' it off using a hose and then if you have it use snowfoam...
volcanic ash is pretty aggressive stuff by all accounts so easy as you go chaps
