Spraying paper pulp is an exciting technique that has us totally hooked. We spray it onto huge sheets of polyester to create gigantic sheets of paper, or spray multiple layers onto porous armatures to make thick sculptural pieces. Almost any dilute pulp can be sprayed onto a wide variety of porous surfaces, molds or armatures, resulting in thick or thin castings. The pulp sprayer must be powered by an air compressor that is at least 1.5 to 2 horsepower, with the air pressure set at 70 psi. We have tried out various types of pulp spraying devices, and have concluded that the "pattern pistol" sprayer is the most reliable and satisfactory model. This is an industrial tool used by masons to spray various sorts of materials onto walls and ceilings. We supply the pulp spraying tool, which is a gun and hopper. The gun is aluminum, with two interchangeable nozzles to double the range of spray pattern and pressure, plus there is a special release valve to turn the air pressure off and on. The plastic hopper, which holds up to 1 3/4 gallons of pulp, will not break or rust. Note: air compressor is not included.