On 01/15/2010 03:46 PM, GarageWoodworks wrote:
On Jan 15, 4:36 pm, "Leon" wrote:

Understood, but going beyond what the instructions called for, do you know
of any reason that you could not use an air tight 20 gal container?

I don't see any reason why you couldn't. The limiting factor with
increased bucket volume will be your shop vac strength. The larger
the volume, the harder the vacuum has to work and vacuum suction
should drop.

Sorry, this is completely wrong. As long as the lid is airtight, it
matters not at all how big the container is. Given that you're reducing
the pressure in the container the only difference from a larger
container is that it will take a fraction of a second longer to get
suction at the end of the hose when you turn on the vac (since you need
to suck the air out of the container first).

I guess it's the same with duct work and a central shop
vac. If the duct work run is too long, suction suffers.

Long duct runs result in an increase in static pressure in the ductwork.
For a given amount of suction from the blower, this results in less
airflow. This is totally separate from the size of the cyclone container.

Chris