Volcanic ash cloud and Private / VFR flying (merged)

[Maoraigh1]

http://www.icenews.is/index.php/2010/04/16/iceland-eruption-could-trigger-more
Looks like this problem may keep repeating.

Does anyone have experience of the effectiveness of aircraft air filters against this stuff? The O-200 filter seems to have a much smaller surface area than a car engine of similar size. Also, of course, a different type of filter.
This is of academic interest to me at present, as our O-200 is having a top overhaul.

From USGS advice re volcanic ash. (For cars etc)
“The most effective method to prevent ash-induced damage to machinery is to shut down, close off or seal equipment until ash is removed from the immediate environment”

“Change oil and oil filters frequently (every 50-100 miles in heavy dust; every 500-1000 miles in light dust).
Do not drive without an air filter. If you can not change it, clean it by blowing air from the inside out. Do not change it until you notice a loss of power to the engine as a dirty filter is more effective than a clean one.”