Abstract: A system and a method for removing a coating from a substrate. The system provides a compressed air source, a heated water source, a particulate cleaning medium source, and a mixing valve including an air input, a water input, and a particulate cleaning medium input. The inputs are positioned on the valve so that the water input is positioned downstream of the compressed air input, and the particulate cleaning medium input is positioned downstream of both the compressed air and water inputs. The method of mixing the air, water, and particulate cleaning medium provides a coating removal mixture having a volumetric ratio of air to water of at least 100:1 and a volumetric ratio of air to particulate cleaning medium of at least 70:1.

Abstract: A system and a method for removing a coating from a substrate. The system provides a compressed air source, a heated water source, a particulate cleaning medium source, and a mixing valve including an air input, a water input, and a particulate cleaning medium input. The inputs are positioned on the valve so that the water input is positioned downstream of the compressed air input, and the particulate cleaning medium input is positioned downstream of both the compressed air and water inputs. The method of mixing the air, water, and particulate cleaning medium provides a coating removal mixture having a volumetric ratio of air to water of at least 100:1 and a volumetric ratio of air to particulate cleaning medium of at least 70:1.

Abstract: A system and a method for removing a coating from a substrate. The system provides a compressed air source, a heated water source, a particulate cleaning medium source, and a mixing valve including an air input, a water input, and a particulate cleaning medium input. The inputs are positioned on the valve so that the water input is positioned downstream of the compressed air input, and the particulate cleaning medium input is positioned downstream of both the compressed air and water inputs. The method of mixing the air, water, and particulate cleaning medium provides a coating removal mixture having a volumetric ratio of air to water of at least 100:1 and a volumetric ratio of air to particulate cleaning medium of at least 70:1.

Abstract: A contaminant shield is located above the finished ceiling in a building or office space and below potential sources of intrusive liquid contaminants to prevent such contaminants from leaking through the ceiling and intruding into the user space therebelow where sensitive electronic equipment may be located. The flat, imperforate expanse of the shield may be sloped to a slight degree such that liquids falling onto the shield are immediately drained therefrom. The shield is formed by a multitude of generally flat panels joined along their opposite sides to elongated, generally horizontally extending supports having provisions for clamp-like, watertight connections with the panels. Joints formed by abutting panels are sealed in a watertight manner through the use of gaskets sandwiched between downturned marginal edges of the panels.