Types of RTV Mold Rubber for Mold Making and Casting, Pros & Cons скачать в хорошем качестве

Types of RTV Mold Rubber for Mold Making and Casting, Pros & Cons

Examining the different types of RTV mold rubber available for mold making and casting from Smooth-On. #moldmaking #casting #tutorial Advantages of Latex Least expensive mold rubber available. Very elastic, thin-walled and strong. Lasts a long time. Offers good abrasion resistance. Good for making glove molds. Disadvantages of Latex Strong ammonia smell. Can only be brushed onto an original. Many coats are necessary. Can take up to two weeks to make mold. Shrinkage. Casting with Latex Good for casting concrete, wax or plaster. Generally not used for casting urethane, polyester, or epoxy resins, or low-temp metal alloys. Advantages of Polysulfide Soft, stretchy, and durable. Last a very long time. Moderate cost. Will cure against water clay or clays containing sulfur. Disadvantages of Polysulfide Accurate gram scale to weigh components. Offensive odor. May stain white plaster during casting. Casting with Polysulfide Good for casting plaster or wax only. Will not handle concrete, resins, or low-temp metal alloys. Advantages of Silicone Rubber Best release properties of all the mold rubbers. Model surface preparation minimal nor not necessary. Release agent for casting often not necessary. Most heat resistance to high temperatures. Can cast low-tempmetal alloys such as tin and pewter. High tear resistance. Knotty tear propagation. Very good chemical resistance. Longest mold life for casting urethane, polyester, or epoxy resins. Disadvantages of Silicone Rubber Price. Require precise measurement. Air entrapment. Vacuum degassing may be necessary Disadvantages of Tin-Cure Silicone Will shrink somewhat over time. Will lose tear strength when stored in library over time. Disadvantages of Platinum-Cure Silicone Most expensive available. Cure inhibition. Casting with Silicone Appropriate for most casting materials. Advantages of Polyurethane Rubber Available in a wide hardness range. Last a very long time. Cost less than silicones and polysulfides. Accurate gram scale often not required. Vacuum degassing generally not required. Disadvantages of Polyurethane Rubber Sticks to most surfaces. Model preparation generally required before pouring. Release agent may be necessary before casting. Moisture sensitive. Very limited shelf life after opening. Casting with Polyurethane Good for casting wax, plaster, concrete and resins. Will not handle the heat of low-temp metal alloys. Make It Now! with Smooth-On http://www.smooth-on.com/   / smoothon     / smoothon   http://www.google.com/+smoothon ~-~~-~~~-~~-~ Adult Supervision Required Keep Out Of Reach Of Children ~-~~-~~~-~~-~