It is important to keep any moisture from reaching the abrasive inside the pressure pot of your sandcarving system. That’s why there is a water separator attached to your pressure pot where the compressed air enters.
The container of the separator can only hold a certain amount of water, so if you do not empty it on a regular basis, the water will still get into your abrasive. Get in the habit of draining your water separator on a regular basis, especially when high humidity is present; this may mean draining it every half hour or so. When those conditions persistently exist, you may want to investigate other water-separation systems.
—Ruth Dobbins, Professional Glass Consultant