Abstract: A spray can for resin paints under pressure incorporates a secondary container in its interior mounted to the normally provided elongated spray tube extending into the can. The secondary container holds a catalyst and is closed off at one end by a cap with cooperating plastic sealing members further functioning to hold a weight in such a manner that the weight in the secondary container can be released by shaking of the can to generate an inertial force. Releasing of the weight shatters the secondary container thereby placing the catalyst and resin in communication with each other, the mixture passing up through the tube and out the normally provided spray outlet when the spray valve is opened.