Crucible 101
The simplest way to provide information on the melting temperatures for various common metals is in a table, which we provide below:
Metal | Celcius | Fahrenheit |
---|---|---|
Aluminum | 659 | 1218 |
Brass | 900-940 | 1652-1724 |
Copper | 1083 | 1981 |
Gold | 1063 | 1946 |
Silver | 961 | 1762 |
How Does Purity Affect Melting and Pouring Temperatures?
However, it's worth mentioning that while these are the general temperatures for melting metals (depending on purity, there may be variations,) there is a different pouring temperature. When pouring into a graphite mold, metal that is too hot will seep into the mold rather than hardening on contact, leaving a rough and bumpy surface. The pouring temperature is going to be hotter than the melting temperature (as the exact melting temperature is also the freezing temperature; the metal has to have time to fill the mold before solidifying.) The trick is to know what temperature the metal is inside the kiln; it's best to pour the metal right out of the kiln, unless it's too hot. With more advanced metal melting kilns, better control of the temperature should be feasible. Here is the table for pouring temperatures:
Metal | Celcius | Fahrenheit |
---|---|---|
Aluminum | 700-750 | 1292-1382 |
Brass | 1000-1120 | 1832-2048 |
Copper | 898-1176 | 1650-2150 |
Gold | 1150-1250 | 2102-2282 |
Silver | 1000-1050 | 1832-1922 |
The purer the metal is, the narrower the melting/pouring range; impurities broaden the range by lowering the required minimum temperature.
Can the Mold Affect Pouring Temperature?
The shape of the mold is an important consideration for pouring temperature. A simple mold, like a sphere or rod, is filled quickly and easily. But a complex design will take more time to fill and will therefore require a higher pouring temperature.
The best outcome will come with experience. Practice regularly with your own Tabletop Furnace, a small kiln that can heat up to your desired temperature in less than 10 minutes using RapidHeat Technology. To learn more, browse our website, or contact us with any questions you may have.