{"product_id":"moulding-plaster","title":"No. 1 Moulding Plaster","description":"\u003cp\u003eAVAILABLE IN 5, 25, AND 50LB OPTIONS IN THE DROPDOWN\u003c\/p\u003e\n\u003cp\u003eUSG No. 1 Moulding Plaster is a high purity general purpose plaster that can be used in a wide variety\u003cbr\u003eof applications including architectural ornamentation and dental use. The physical properties can\u003cbr\u003ebe varied depending upon the desired end use, while the use consistency can vary from a practical\u003cbr\u003erange of 63 lbs. water\/100 lbs. of plaster (29 kg water\/45 kg plaster) to as high as 70 lbs. water\/\u003cbr\u003e100 lbs. of plaster (32 kg water\/45 kg plaster).\u003c\/p\u003e\n\u003cp\u003eUSG No. 1 Moulding Plaster is noncombustible. With a coefficient of thermal conductivity (k) of\u003cbr\u003e0.25 to 4.0 depending on density and additives, USG No. 1 Moulding Plaster can help to provide a\u003cbr\u003ehigh degree of fire resistance. When dry, USG No. 1 Moulding Plaster is electrically nonconductive\u003cbr\u003eand makes a good insulating medium.\u003c\/p\u003e\n\u003cp\u003eMIXING INSTRUCTIONS\u003c\/p\u003e\n\u003cp\u003eUse potable water at temperatures between 70 °F (21 °C) and 100 °F (38 °C). Because variations\u003cbr\u003ein slurry (USG No. 1 Moulding Plaster and water mixture) temperature produce variations in set\u003cbr\u003etime, it is important to keep both the USG No. 1 Moulding Plaster and water in a stable temperature\u003cbr\u003eenvironment prior to use. The higher the temperature of the slurry, the shorter the set time.\u003cbr\u003eConversely, the lower the temperature of the slurry, the longer the set time.\u003c\/p\u003e\n\u003cp\u003eWeigh both the USG No. 1 Moulding Plaster and the water prior to use for each mix. The water-to-\u003cbr\u003eUSG No. 1 Moulding Plaster ratio is critical because it governs the strength and the density of the\u003cbr\u003efinal cast.\u003c\/p\u003e\n\u003cp\u003eSift or strew USG No. 1 Moulding Plaster into the water slowly and evenly. Do not drop large\u003cbr\u003eamounts of USG No. 1 Moulding Plaster directly into the water as proper soaking of the USG No. 1\u003cbr\u003eMoulding Plaster may not occur. USG No. 1 Moulding Plaster should be fully dispersed in the water\u003cbr\u003eprior to mixing. Small batches require less soaking time than large batches. See USG IG503 Plaster\u003cbr\u003eMixing Procedures for specific soaking instructions.\u003c\/p\u003e\n\u003cp\u003eMixing USG No. 1 Moulding Plaster slurry is one of the most important steps in producing USG\u003cbr\u003eNo. 1 Moulding Plaster casts with maximum strength, absorption, hardness and other important\u003cbr\u003eproperties.\u003c\/p\u003e\n\u003cp\u003eMechanically mixed slurries develop uniform casts with optimal strengths. USG No. 1 Moulding\u003cbr\u003ePlaster can be mechanically mixed through both batch and continuous processes. Proper blade\u003cbr\u003eand bucket dimensions are important for obtaining the best batch mix (see USG IG503 Plaster\u003cbr\u003eMixing Procedures for details).\u003c\/p\u003e\n\u003cp\u003eLonger mixing times result in higher mold strength and shorter set times.\u003c\/p\u003e\n\u003cp\u003ePOURING\u003c\/p\u003e\n\u003cp\u003eTo prevent air entrainment and provide a uniform, smooth surface, careful pouring of USG No. 1\u003cbr\u003eMoulding Plaster slurry is necessary. Agitation\/vibration of the filled mold is a further step used\u003cbr\u003eto prevent air at or near the mold surface. Whenever possible, USG No. 1 Moulding Plaster slurry\u003cbr\u003eshould be poured carefully in the deepest area so that the slurry flows evenly across the surface of\u003cbr\u003ethe case mold.\u003c\/p\u003e\n\u003cp\u003ePouring a large amount of slurry directly on the face of the case mold may result in slight\u003cbr\u003edensification of the USG No. 1 Moulding Plaster mold at the point where it strikes the surface of the\u003cbr\u003ecase. This produces a hard spot, giving uneven absorption.\u003c\/p\u003e\n\u003cp\u003eDRYING\u003c\/p\u003e\n\u003cp\u003eAll casts should be dried as quickly as is safely possible after manufacture so that maximum\u003cbr\u003ephysical properties can develop. Dry to a constant weight.\u003c\/p\u003e\n\u003cp\u003eThe best drying rooms or ovens provide 1) uniform and rapid circulation (minimum of 15-30 fps\u003cbr\u003e(4.6-9.1 mps)) of air with no “dead spots” having little or no air movement, 2) equal temperatures\u003cbr\u003ethroughout the entire area, and 3) provisions for exhausting a portion of the air while replacing\u003cbr\u003eit with fresh air. High humidity surrounding the drying room or oven inhibits drying efficiency\u003cbr\u003ebecause the air pulled into the room is incapable of picking up much moisture from the molds.\u003c\/p\u003e\n\u003cp\u003eThe maximum temperature at which USG No. 1 Moulding Plaster molds are safe from calcination is\u003cbr\u003e120 °F (49 °C). With substantial free water in the mold, a higher drying temperature can be used\u003cbr\u003ewithout difficulty. As drying progresses, the temperature must be reduced to prevent calcination.\u003cbr\u003eBefore removing molds from the dryer, the temperature should approach that of the area around\u003cbr\u003ethe dryer to prevent thermal shock. See IG502 Drying Plaster Casts for additional information.\u003c\/p\u003e\n\u003cp\u003eSTORAGE AND USE\u003c\/p\u003e\n\u003cp\u003eWhen properly used, USG No. 1 Moulding Plaster is easy to work with and complies with the federal\u003cbr\u003eLabeling of Hazardous Art Materials Act, 12 U.S.C. Section 1277 and ASTM D4236. Keep indoors\u003cbr\u003eat temperatures between 65 °F - 75 °F (18 °C - 24 °C) and 45% - 55% RH. Do not stack more than\u003cbr\u003etwo pallets high. Keep from drafts. Rotate stock. USG No. 1 Moulding Plaster should be used within\u003cbr\u003e6 months of the manufacturing date located on the package. Always follow handling and use\u003cbr\u003edirections and safety warnings on the package.\u003c\/p\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/www.usg.com\/content\/dam\/USG_Marketing_Communications\/united_states\/sds\/usg-no-1-moulding-plaster-sds-en-52000000006.pdf\" rel=\"noopener\" target=\"_blank\"\u003eSDS\u003c\/a\u003e\u003c\/p\u003e","brand":"USG","offers":[{"title":"5lb","offer_id":48015590850875,"sku":"47000","price":15.0,"currency_code":"USD","in_stock":false},{"title":"25lb","offer_id":48015590818107,"sku":"47000A","price":29.0,"currency_code":"USD","in_stock":true},{"title":"50lb","offer_id":48015590785339,"sku":"47000B","price":37.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0780\/7539\/6411\/files\/moulding.jpg?v=1710986955","url":"https:\/\/maacaffestore.com\/products\/moulding-plaster","provider":"The Compleat Sculptor, Inc","version":"1.0","type":"link"}