Document 5Gbkx2597b1OVn1mL7gj7Md5

United States Gypsum* PLASTERING MATERIALS PM 142 AUDICOTE Over IMPERIAL Basecoat SUBJECT: Tentative Specifications AUDICOTE* Acoustical Plaster Over IMPERIAL* Basecoat Plaster USE AUDICOTE Acoustical Plaster may be hand or machine applied to various thicknesses, dependent on noise reduction requirements, over properly prepared, set, semi-dry or dry IMPERIAL Basecoat Plaster. GENERAL CONDITIONS Protect plastering materials from moisture during storage. Maintain temperature in building at minimum comfortable working range, about 55-6oF, and air circulation at minimum level, for an adequate period prior to, during, and following IMPERIAL Basecoat application, until basecoat is set. During and following AUDICOTE Acoustical Plaster application, maintain temperature above 55F and provide uniformly distributed air circulation adequate to cause continuous removal of moisture from building, until plaster is dry. ,,.. IMPERIAL BASECOAT PLASTER Mixing - Use a cage type mixing paddle driven by a heavy duty drill producing a minimum of 650 RPM UNDER IX5AD. Place approximately 8 to 10 quarts of clean water In a 12 to 15 gallon smoothside container, and with the mixer operating, slowly add one bag of plaster. Mix for a minimum of 2 minutes, but no longer than 5 minutes to disperse all lumps completely. Mixing equipment and all tools must be kept clean. o O' 0* 41 United States Gypsum c -2- C Application - Apply IMPERIAL Basecoat Plaster only over IMPERIAL Plaster Base which has had all Joints covered with IMPERIAL Joint Reinforcing Tape. Embed tape with a tight thin coat of IMPERIAL Basecoat Plaster, allow to set, then apply basecoat over entire surface to 1/16" to 3/32" thickness. Leave surface level by darbying with a serrated edge darby. Allow to set and dry sufficiently to provide proper suction for AUDICOTE. To avoid "photographing" through thin applications of AUDICOTE Acoustical Plaster, large ridges or other sharp surface irregularities in the basecoat must be leveled by floating or lightly troweling after basecoat takes up. This plaster will set in approximately 1 hour. Do not mix more than can be applied in 30 minutes. Do not retemper. AUDICOTE ACOUSTICAL PIASTER Mixing - For spray application, add 1 bag to approxi mately 55 quarts clean water and mix 5 to 7 minutes to develop proper application qualities. Reduce water usage as desired for hand application. Do not overmix. For spray-applied finish coat use 70 to 90 quarts of water per bag, adjusting to suit machine used and texture desired. Hand Application - For total thicknesses up to 3/16" Apply In one coat by scratch-double up procedure, with double up application at right angle to scratch. Level surface with darby and trowel as it is applied, allow to take up, then stipple, stipple and perforate, float, trowel, or spray texture to obtain desired finish. For total thicknesses 3/16" to 1/2" - Apply first coat to within 1/16" of desired total thickness In one or two applications, depending on suction of basecoat. Level surface with darby and trowel and allow to dry sufficiently to provide smooth, even, absorptive base for finish coat. To provide adequate suction, coats over 1/h" thick normally require drying completely; coats 3/16" - 1/4" thick, overnight drying. Fill imper fections, when necessary, with a skim coat, then sprayapply or hand-apply finish coat 1/16" to 1/8" thick. For hand applied finish coat, level surface with darby and trowel as it is applied, allow finish to take up, then stipple, stipple and perforate, float or trowel to produce desired finish. Avoid over-troweling. I3B019 0 5 7 0 \ * -3- t Machine Application - Apply with machine which can deliver low motor volume, such as commonly used for spraying plaster textures. Apply material to ceiling in two to more passes, first across ceiling in one direction, then at right angle to first pass, to 1/8" - 1/4" total thickness. For thicknesses over 1/4" allow first coat to dry completely before applying subsequent coats. When a fine textured finish coat is desired, level surface of previous coat with darby and trowel and allow to dry sufficiently to provide absorption for finish coat. SYSTEM CHARACTERISTICS 1. Light Reflectance - 65 to 70dependent on texture; finer texture gives higher light reflectance. 2. Noise Reduction Coeffecient - AUDICOTE Thickness Approximate NRC 1/8" 3/16" 1/4" 3/8" 1/2" 0.36} 0.42} 0.46} 0.501 0.552 U.S.G. Research Center Recognized independent laboratory 3. Texture Range - Fine to moderately coarse, dependent on application procedure, water usage, mortar flow volume, dispersing air pressure, and nozzle orifice size. LIMITATIONS 1. AUDICOTE Acoustical Plaster is not a "hard" finish. It is not recommended for applications where acous tical sound absorption is not a requirement. 2 While minor irregularities in the basecoat surface will be hidden by the nature of the AUDICOTE Acous tical Plaster texture, sharp changes in level of the sub-surface may "photograph" through AUDICOTE applications less than 3/8" in thickness. 3. Do not use on walls or other areas subject to abuse or contact. I3B01? 0571