In a busy shop, dust settles on every horizontal surface, including the top bag of your dust collector. Whenever the collector is turned on and the bags inflate, all that dust on top gets blasted into the air. To prevent this from happening, hang a cardboard box upside down over the dust collector. String it from the ceiling. This “lid” only has to be large enough to allow good airflow to escape the top bag, and it will keep airborne dust from settling on the fabric. Plus, it won’t interfere with emptying the bottom bag.