| Appendix A - Definitions |
| Accelerator - | A substance which increases the rate of cure. |
| Alginate - | Any of several derivatives of alginic acid derived from seaweed or sodium alginate reacted with calcium salts for making masks and castings. |
| Alloy - | To mix, as metals, so as to form a compound. |
| Block Mold - | A term used in mold making to describe a mold in which the silicone completely fills the area between the master and mold support. The exterior of the mold does not conform to the shape of the master. |
| Casting - | To form (liquid metal, for example) into a particular shape by pouring into a mold. |
| Catalyst - | A substance used to significantly accelerate a chemical reaction. |
| Concrete - | A hard, strong construction material consisting of sand,conglomerate gravel, pebbles, broken stone, or slag in a mortar or cement matrix. |
| Cure Time - | The time a sealant takes to develop its full properties. |
| Curing - | To prepare, preserve, or finish (a substance) by a chemical or physical process. To vulcanize (rubber). |
| Degassing - | To remove gas or air from. |
| Die Stone - | A dental product made from gypsum that has a compression strength usually over 18,000 PSI. |
| Form - | A mold for the setting of concrete, plaster, silicone or other agent until it cures. |
| Gypsum - | A widespread colorless, white, or yellowish mineral, CaSO4·2H2O, used in the manufacture of plaster of Paris, various plaster products, and fertilizers. |
| Latex - | An emulsion of rubber or plastic globules in water, used in paints, adhesives, and various synthetic rubber products. |
| Ladle - | A vessel to carry liquid metal from the smelting pot to the mold. |
| Lead - | A soft, malleable, ductile, bluish-white, dense metallic element, extracted chiefly from galena and used in containers and pipes for corrosives, solder and type metal, bullets, radiation shielding, paints, and antiknock compounds. Atomic number 82; atomic weight 207.2; melting point 327.5°C; boiling point 1,744°C; specific gravity 11.35; valence 2, 4. |
| Library Life - | A term referring to the length of time a mold can sit in storage with deteriorating. |
| Master - | Being an original from which copies are made. |
| Mold - | A hollow form or matrix for shaping a fluid or plastic substance. |
| Mold lines - | Lines showing up on the finished cast caused from molds made up of two or more pieces. |
| Naphtha - | Any of several highly volatile, flammable liquid mixtures of hydrocarbons distilled from petroleum, coal tar, and natural gas and used as fuel, as solvents, and in making various chemicals. |
| Negative - | The reverse impression of the master that is left in the mold. |
| Pewter - | Any of numerous silver-gray alloys of tin with various amounts of antimony, copper, and sometimes lead, used widely for fine kitchen utensils and tableware. |
| Plaster - | A mixture of lime or gypsum, sand, and water, sometimes with fiber added, that hardens to a smooth solid and is used for coating walls and ceilings or casting figurines and other items. |
| Potlife - | The term referring to the cure rate of a silicone RTV. |
| Pressure Casting - | A casting technique of using compressed air in a pressure pot to reduce or help eliminate air bubble from castings. Typically used when casting resins. |
| Pressure Pot - | A specially designed container for casting under pressure. |
| Pulls - | An expression referring to the number of parts obtained from a mold. |
| Release Agent - | A compound or solution to allow a newly cast object to be released from it's mold. Or to keep the original from sticking to the mold making material. |
| RTV - | RTV Silicone are a rubber like polymer called polydimethsiloxanes. RTV stands for room temperature vulcanizing, or simply a rubber which cures at room temperature. Silicone rubber adhesives are made from a complicated process that turns elemental silicon metal made from sand (silica) into a rubbery polymer. When cured, silicone rubber adhesives/sealants have excellent resistance to heat (500-600ºF) and moisture which makes them exceptionally suited for outdoor weathering applications, such as sealant and caulking compounds in the construction industry. A silicone rubber usually of a two part composition which cures at room temperature. RTV silicone moulds typically yield upwards of 100 or more casts with incredible detailed reproduction of the pattern. |
| Shelf Life - | The amount of time a product may be used without deterioration. |
| Shore Hardness - | A scale of measurement used to describe the hardness of a material when measured with a durometer. There are three commonly used scales, in degrees of increasing hardness: Shore 00, Shore A and Shore D. |
| Slip Mold - | A mold usually made of latex that when filled with casting media is pulled off the casting like a slip. |
| Smelt - | To melt or fuse (ores) in order to separate the metallic constituents. |
| Split Mold - | A two piece mold used to create castings that could otherwise not be made with a single mode or slip mold. |
| Tear Strength - | A test technique used to measure the force required to initiate or propagate a tear into a material sample, measured in pounds per inch "PPI". |
| Tensile Strength - | A method to measure the force required to rupture the material (stress-strain at break) per unit area subjected to a specific dynamic load, usually expressed in pounds per inch. |
| Tin - | A malleable, silvery metallic element obtained chiefly from
cassiterite. It is used to coat other metals to prevent corrosion and is a part of numerous alloys, such as soft solder, pewter, type metal, and bronze. Atomic number 50; atomic weight 118.71; melting point 231.89°C; boiling point 2,270°C; specific gravity 7.31; valence 2, 4. |
| Undercuts - | A term describing the complexity of a shape; these areas are very deeply indented or cut, and therefore require that the mold be pulled and stretched around them in order to remove the mold. |
| Vacuum - | A space in which the pressure is significantly lower than atmospheric pressure. |
| Vacuum Chamber - | A Specially designed chamber that is designed to hold a vacuum. |
| Vacuum Pump - | A mechanical device designed to remove air from a vacuum chamber. |
| Vaseline - | A yellowish translucent substance, almost odorless and tasteless, obtained as a residue in the purification of crude petroleum, and consisting essentially of a mixture of several of the higher members of the paraffin series. It is used as an unguent, and for various purposes in the arts. |
| Vent Channels - | Channels cut into a mold to allow the escape of air. |
| Viscosity - | resistance of a liquid to sheer forces (and hence to flow) |
| Wet Water - | Water that has had a small amount of liquid soap mixed in with it to reduce the surface tension of the water. |
| Worklife - | A term used to indicate the amount of time an end user has to work with a curing silicone. |
