Abstract: A portable fluid dispensing apparatus comprising an fluid reservoir, an air compressor, and a dispensing gun. The fluid reservoir is fitted with a pressure switch which regulates the pressure within said fluid reservoir. Once fluid is charged into the fluid reservoir, the air compressor is activated to pressurize said fluid reservoir and the apparatus is ready for use. The fluid dispenser is then transported to the servicing site. An operator pulls the trigger on the dispenser gun for delivery of fluid on demand. When the pressure in the fluid reservoir drops, the air compressor is automatically triggered to raise the pressure to the predetermined set point. The fluid reservoir may be replenished with fluid as needed by simply depressurizing the fluid reservoir, refilling and repressurizing same. The fluid dispenser may additionally be fitted with a manually operated pump. The fluid reservoir may also be thermally insulated with heat tape to maintain the desired viscosity of the fluid contained therein.