Dust Collector question

I have a Grizzly Dust collector which has, up to now, been just fine. Lately I've noticed a drop in efficiency so I cleaned out the lower bag, checked for leaks in the system and any blockages in the PVC 4" pipes - all seems ok. I have an add-on upper bag which is supposed to filter better that the supplied one. I have never tried to clean it mainly because the lower bag gets all the sawdust, etc.
Should I try to clean the upper bag and how? Doesn't seem like there's anything to 'empty' but appears that there's a fine coating of dust along the walls. Would this result in reduced suction? I guess I could try a shop vac.
Thanx,
Vic
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On Wed, 27 Aug 2008 09:16:36 -0700, "Vic Baron"

Hi Vic,
Yes, it is the upper bag that needs to be cleaned... (The lower bag just contains the stuff that falls so it is not directly related to changes in efficiency.)
I don't know any fancy way to clean the upper bag, but a shop vac certainly would not hurt, and others may suggest better methods.
All the best,
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Kenneth

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Kenneth wrote:

I take my upper back outside, turn the bag inside out and shake the dust out. Make sure you're up wind from the bag.
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Jack Novak
Buffalo, NY - USA
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Whack it with a stick.
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Vic Baron wrote:

The upper bag will get a fair bit of fine dust, which will clog the pores and reduce airflow. DON'T use a shopvac right up against the fabric, as the airspeed is too high and could damage the fabric.
Try just holding onto the fabric at different spots and shaking it. You should see a fair bit of the dust cake just fall off and into the lower bag.
Chris
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Thanks Chris - that makes sense. I'll give it a shot.
Vic
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