Knock Shop Vac Filter Dust Loose Inside a Tied-Off Trash Bag

The Problem

When a shop vac's suction fades, the filter is usually caked, not dead — a pleated filter chokes long before it wears out. The instinctive fix is to take it outside and whack it against a post, which works, but puts you inside the cloud of the finest dust the filter caught: exactly the fraction you least want to breathe.

The Technique

1. Drop the filter into a trash bag.
2. Gather the bag closed around your wrist, so your hand is inside holding the filter and the bag is sealed at your forearm.
3. Bang the filter against something solid — floor, bench leg, post — through the bag.
4. Let the dust settle a few seconds, ease the filter out, and tie off the bag.

The filter comes out working like it should, and the dust ends up in the trash instead of in the air, on your clothes, and back on the shop floor for the vac to pick up a second time.