a pneumatic dispenser for dispensing viscous material , for example , mastic caulk , from a container is described . the dispenser comprises a fluid supply arrangement for accepting a dispensing nozzle of the container and providing a flow of pressurized fluid to the dispensing nozzle to enable the material to be dispensed as a spray . a moveable member can be used to control the flow of pressurized fluid , for example a member disposed on a cap for closing a container containing compartment of the dispenser and / or a moveable member disposed around the dispensing nozzle . the arrangement of the fluid supply arrangement allows for convenient control of the pressurized fluid flow for spraying the material . also disclosed is a dispenser with a readily exchangeable pressure application interface for applying a dispensing pressure to the container , enabling the dispenser to be used with both cartridge and foil pack containers .