Cleaning fluid cartridge

A cleaning fluid cartridge configured to be insertable into a handle of a material applicator, the cleaning fluid cartridge comprising:

• a cylindrical housing having an exterior, an interior bore, a top end, and a bottom end;
• a piston located in the interior bore of the cylindrical housing intermediate the top and bottom ends, the piston being free of connection to structure outside of the cylindrical housing;
• a radial hole extending through the housing from the exterior to the interior bore, the radial hole located between the piston and the bottom end of the housing for transmitting pressurized air supplied from the material applicator into the interior bore below the piston when the cleaning fluid cartridge is positioned in the handle of the material applicator;
• at least one upper o-ring seal located on the exterior of the housing adjacent the top end of the housing for engaging the handle when the cleaning fluid cartridge is positioned in the handle of the material applicator;
• at least one lower o-ring seal located on the exterior of the housing between the radial hole and the bottom end of the housing for engaging the handle when the cleaning fluid cartridge is positioned in the handle of the material applicator;
• a cleaning fluid suited to dissolving plural component materials dispensed by the material applicator, the cleaning fluid being located between the piston and the top end;
• and
• a plug in the housing bottom end and sealed to the cylindrical housing, the plug having a grippable tab extending downward and having ears extending radially outward for engaging the material applicator and locking the cleaning fluid cartridge in the handle.