A foam spraying rig comprising a vehicle having first and second fluid spray component storage tanks mounted in the body of the vehicle, each of which are heated by electrical heaters and by tubing which is connected to the coolant of the water cooled engine of the vehicle. The rig also includes a heat exchanger tank including first and second heat exchangers, each of which have inlet and outlet ends. The outlet ends of the fluid component storage tanks are connected to the inlet ends of first and second pumps, respectively. The outlet ends of the first and second pumps are fluidly connected to the inlet ends of the first and second heat exchangers, respectively. The outlet ends of the first and second heat exchangers are fluidly connected to a spray nozzle which sprays the components onto a surface such as a wall surface or a truck bed.