An aerosol system or method for mixing first and second materials. The system comprises first and second container assemblies and a coupler. The first container assembly contains the second material and a propellant material that pressurizes the second material. The second container assembly contains the second material. The coupler is arranged to couple the first and second container assemblies, thereby forcing the second material into the second container assembly such that the first and second materials mix. The resulting mixture may then be dispensed from the second container assembly using an actuator member. In one case, the first container assembly comprises a male-type valve assembly and the second container assembly comprises a female type valve assembly. In another case, the first material is a catalyst and the second material is a pigmented liquid, which, when mixed, are suitable for repairing a damaged surface.