In dry climates, draining the water separator once or twice a day is sufficient; but in humid areas, you may need to empty it once every half hour. Any time air is compressed, it is squeezed under pressure and any moisture in the air that is squeezed out with it has to go somewhere. It is the job of the water separator to collect this moisture, hence the container at the bottom of the gadget.
The container only holds a certain amount of water and when full, it needs to be emptied. When the separator’s container is full, the water has no other place to go but into the pressure pot. At best, damp abrasive causes intermittent sputtering while sandcarving until the whole system shuts down with the caked-up abrasive clogging the hoses and machine completely. Ultimately, having to take a system apart to get all the damp abrasive out for drying costs precious time for production.
-Ruth Dobbins, Etch Master