In article ,
"Dan Bollinger" wrote:

1. The number one myth must be that PVC ducts are dangerous. As both theory
and
practice show, home shop Dust Collector explosions are somewhere between
extraordinarily rare and nonexistent. The volume of a typical run of 4 inch
duct, say 20 feet, is about 1.7 cubic feet or equal to a cube 14 inches on a
side. I do not know the explosive power of this volume of dust, but I do not
think this is going to level your shop.

2. The number two myth must be that you can ground PVC. You simply can't
ground
an insulator. There are things you can do to reduce the odds of a strong
discharge, especially to your body, but they are far from perfect.

3. The number three myth is the unstated corollary to myth #1: the only thing
of
concern in a dust collector are the ducts. As seen above, the collected dust
pile and the collection bag are greater hazards than the ducts. Fortunately,
in
practice home shop sized dust bags have shown themselves to pose little
explosion hazard.

HEY! 'Zat a dead horse o'er yonder?

The Discovery Channel's Myth Busters aired an episode in which the crew
tried to "invent their own static cannon to learn if an unfortunate
construction worker really died from sandblasting a PVC pipe on the job."
They couldn't get the PVC to generate anything other than a very weak
static discharge.

They also attempted to ignite wood dust suspended in air in a more
recent episode. Had a very difficult time getting it to do much more
than minimally increase the flame area of an open flame - certainly
didn't come anywhere near igniting all the dust in the enclosure.

Just wanted to add some off-the-tV expertise.

Owen
(who must really be living life on the edge with his ungrounded ABS dust
piping)