Two-part reactive polymeric coatings are prepared and applied from an integral dispensing system. The reactive components are held in two separate containers held together by a coupling. Each container is sealed by a pierceable membrane. A piercing tube is disposed within the coupling. In use, the containers are twisted together to cause the tube within the coupling to pierce each of the membranes. Breakaway tabs protect against inadvertent displacement of the containers and provides a clear indication of whether the tube has pierced the membranes. Differential pressure between the containers causes the components to mix and begin to react; a net positive pressure with respect to the ambient atmosphere permits the mixed components to be applied as a spray. An externally mounted spray feed tube provides great flexibility in application of the paint being sprayed.