Empty the collection drums when they are three quarters full or less. If the drums become overfilled, the dust will be sucked into the intake barrel and passed through to the canister filters. How quickly the drum will fill up is based on the type of work being done at the time: | Empty the collection drums when they are three quarters full or less. If the drums become overfilled, the dust will be sucked into the intake barrel and passed through to the canister filters. How quickly the drum will fill up is based on the type of work being done at the time: |