Green Sand Metalcasting Foundry News

T - Foundry Additives Glossary

TALC (See: SOAPSTONE)
Talc is a hydrated magnesium silicate with the composition [4SiO₂ 3MgO • H₂O]. It is a soft, friable mineral having an oily touch. It has a Moh's hardness of 1 and a specific gravity of 2.8. It is referred to as "soapstone." It is used as a parting compound when impregnated with wax and ground. It has been used in nonferrous mold coatings, ladle refractory coatings, and when blended with clay, bentonite, cereal or dextrin, it is used as a core paste. It is used as an additive in various core compounds and core fillers.

TANNIC ACID (See: BINDERS-CORE BINDERS)
Is prepared from extraction of the liquid squeezed from wetted oak bark. It is rarely, but sometimes used as an auxiliary binder in core sand mixtures where clay is present.  

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P - Foundry Additives Glossary

PANTHER CREEK (See: BENTONITE-BONDS-CLAY-SOUTH­ERN BENTONITE)

PARAFFIN (See: WAX)
It is one of the waxes used for making wax patterns in the "Lost Wax Process." It is used as a release agent for liquid partings when it is dissolved in a liquid carrier such as kerosene. (See: PARAFFIN OIL.)

PARAFFIN OIL (See: OILS)
This is the drip oil from the wax presses in processing an extracted paraffin wax from the wax bearing distillate in the refining of petroleum. The oil is treated, redistilled, and separated into various grades of lubricating oils varying from light to heavy. They may be treated and bleached with sulfuric acid, or neutralized with an alkali. They may be bleached with acid. The specific gravity of paraffin oil varies between 21° and 26° Baume. Paraffin oil is used in many liquid foundry parting compounds when blended with kerosene, which is used as the carrier oil. It is usually soluble in ether, benzene and essential oils.

PARTING COMPOUND (See: AGATE-DRY PARTING-FUEL OIL-KEROSENE-LIQUID PARTING-LYCOPODIUM­ MICA-MINERAL FLOUR-PARAFFIN OIL-PARTING RELEASE AGENT-SOAPSTONE-TALC-WAX)
Materials used to separate patterns from the molding or core sand mixtures. Parting compounds may be dry parting dusted or sprayed as a liquid parting onto the patterns or core boxes so as to prevent any mold or core adherence.

PARTINGS (See: DRY PARTING-LIME-LIQUID PARTING­-LYCOPODIUM-MICA-MINERAL FLOUR-PARTING COMPOUND-TALC) 

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O - Foundry Additives Glossary

OAT FLOUR (See: CEREAL)
Although oat flour is used in the foundry in core and molding sand mixtures it is used sparingly. Corn flour, gelatinized, is generally preferred. Oat flour doesn't give the deformation and strengths in sand mixtures as does corn flour cereal.

OHIO FIRE CLAY (See: FIRECLAY)
Is a plastic fireclay bond which is a sedimentary clay deposit. They are coal measure clays. The Ohio fireclays that are used for bonding purposes are refractory. When finely ground they are called "bonding clays"; when more coarsely prepared, they are said to be "refractory clays," for use in ladles, furnaces, and other such mix­tures.

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M - Foundry Additives Glossary

MAGNESITE
Is a refractory mineral called magnesium carbonate (MgCO3). It has some contaminants present, such as iron carbonate (FeCO3) and ferric oxide (Fe2O3) present. Its specific gravity is 3.1 and it is fused at 3929°F. (2165° C.). For foundry preparation and use it is a very valuable refractory aggregate particularly where basic refractories are required. Magnesite, when finely ground, is added to chrome sand mixtures as (MgO). MgO is also used as a foundry sand in certain mixtures. Where basic lined furnaces are in operation, dead burned magnesite is used. It is a hard, dense, granular material obtained by calcining magnesite rock at a temperature high enough to form a product inert to atmospheric moisture and carbon dioxide. It is chiefly magnesia (MgO) and is a basic refractory. In the casting of manganese steel, olivine sand or chromite Hevi-Sand containing 10% to 15% MgO addition is an excellent core sand base.

MANGANESE DIOXIDE
An oxidizing agent, MnO2, can be made synthetically or may be found as an ore, known as "bog manganese" or "wad." It has many uses in the foundry, one use being in core sand mixtures for oxidizing purposes. Small amounts are used, such as 0.25 percent.

MENHADEN OIL (See: CORE OIL-OILS)
An oil obtained by steaming or boiling fish caught along the U.S.A. Atlantic coast line. It is also called, "Porgy Oil," "Whitefish Oil," and in the South it is called, "Fatback" and "Moss Bunker." The oil contains 27% oleic acid, stearic acid and a few fats, so that it polymerizes as easily as vegetable oil used in core oils.

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