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Is your investment hazardous?
Are these control chemicals hazardous to your health?
How long should I wait to quench out my gypsum molds?
Are there any uses for theh spent (used) investment? Can I grind the material
and add it back into fresh material at some small ratio?
Do investment molds shrink?
What investment is recommended to cast (palladium) white gold?
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Jewelry Questions
Is your investment hazardous?
Due to the presence of respirable particles (<10 microns) of crystalline silica in investments, these products do carry a respirable warning.
It is extremely important to determine the level of exposure to which your operators are regularly subjected. The Material Safety Data Sheet (MSDS) outlines the personal protection guidelines for operators,
based on the amount of exposure. Refer to the MSDS for the product you are using and contact a health and safety expert with any questions you may have.
Are these control chemicals hazardous to your health?
Each control chemical is used in a very small quantity in the investment formulation. Regardless, none of them are hazardous to your health.
How long should I wait to quench out my gypsum molds?
Usually, quenching occurs shortly after the sprue button looses its red glow. If you quench too soon, you may alter the grain structure and create a rough surface. If you wait too long, the investment
may be a little more difficult to remove and will quench less efficiently.
Are there any uses for the spent (used) investment? Can I grind the material and add it back
into fresh material at some small ratio?\
Although there are probably a number of practical uses for the spent investment, we cannot recommend anything other than disposal. After casting, the investment may carry traces of heavy metals that can
limit other potential uses.
Because the thermal properties of the investment have been permanently altered by the burnout cycle, the spent investment is very different from the new investment. Do not try to add the spent material into fresh
material in any ratio. It will ruin the fresh investment.
Do investment molds shrink?
Yes, but the amount of shrink is very small, around 1%. Keep in mind that the wax, metal and investment all shrink during some part of the casting process.
What investment is recommended to cast (palladium) white gold?
Unlike other gold alloys, this material melts at high (2200oF or 1200oC) temperature. This temperature is also where gypsum materials start to decompose. You can cast in gypsum
investment, but the process is sensitive to technique. You are advised to get both the metal and flasks as cool as possible to completely fill the mold and reduce the risk of the mold degrading. Keep
the sprues thick and short. If mold temperature were the only consideration, you would select a phosphate material to cast white gold. However, the strength of the phosphate makes it difficult to
remove the cast piece.
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