Abstract: Insulating foam producing and delivering apparatus includes foaming agent and resin supplies, means for delivering the foaming agent and resin and also air under pressure and a foam gun for generating the foam and mixing the foam with the resin. The foam gun includes a foaming chamber in which foaming agent and air are discharged in jets so as to impact against blades of a free spinning propeller which is turned by jets to create a mixing turbulence and thereby whips the foaming agent and air into the desired froth or foam. The foam is combined with the resin through an extended resin discharge nozzle located downstream of the foaming chamber so as to confine the resin mixing essentially to the output applicator or dispenser hose and thereby to minimize clogging due to hardened resin residue. Transparent air, foaming agent and resin supply lines enable constant monitoring of the ingredients and facilitate the maintenance of the desired foam density and other desired conditions of the foam.