"Dave Martindale" wrote in message
...
Jim Yanik writes:

I take a craftsman wet/dry vac and have a real long hose.
Then I remove the internal filter. The vac is placed outside
turned
on.
I take the hose inside and go to town. Sucks everything outside
and
doesnt
clog the vac. Works real well. I got the 20' hose from sears.

but you are pulling dirt into your vac's MOTOR,it's not good for it.
Filters keep the dust from ruining your motor bearings/brush
contacts.

That's true for ordinary household vacuums, which run the dirt
pickup
air through the motor (after the filter) for cooling. But all of
the
shop vacs I've ever looked at have a separate path for motor cooling
air. Motor cooling air comes from the space around the motor via
slots.

You really need this change in construction for vacuuming up water.
The
filter for water pickup (particularly if it's just a foam sleeve,
not a
pleated filter) lets some water through, and you don't want water
inside
your motor no matter how briefly. Also, shop vacs normally have a
float
valve so when the tank fills up with water the float blocks the
impeller
inlet instead of having the vacuum start spewing water out the
outlet
port. Once this happens, there's no air flow at all through the
tank,
but the motor still needs cooling air. Again, a separate motor
cooling
air path solves this problem.

Good central vacs for houses also seem to use separate motor cooling
air, though I've seen one that cooled the motor with the filtered
air.
If you throttled the air flow by putting a small nozzle on it, the
motor
would overheat and trip a thermal protector after a few minutes on
that
particular unit.

There's still the issue of chunks sticking in the blower, stopping it
or throwing it off balance, or just plugging it up over time.

Bob