The invention is directed toward a mobile wet-abrasive blasting system used for cleaning, preparing surfaces, removing coatings, and other abrasive blasting applications. The wet abrasive basting system has a blast pot that includes pilot-controlled pneumatics to control the loading, pressurizing, de-pressurizing, and wash down functions. The wet-abrasive blasting system also uses a floating bung in conjunction with a vent mechanism to further automate the pressurizing steps in setting up the system. The wet-abrasive blasting system also uses pilot-controlled pneumatics to decide the blasting function options of just water, just air, or water/abrasive mix and air. Wet-abrasive blasting systems mix an abrasive media with water and convey the mix to meet compressed air and direct through a blast hose and nozzle.