The melting point of zinc is 419.5 °C. This is low for a metal, and it is precisely this low melting temperature that makes zinc popular for DIY casting. If you want to get started, you'll need a melting furnace that comfortably exceeds 419.5 °C.
At what temperature does zinc melt?
Zinc melts at 419.5 °C, or 692.7 Kelvin or 787.1 °F. Below this temperature, zinc remains a solid, bluish-white metal with atomic number 30 and symbol Zn. Above it, it becomes liquid and can be cast.
This value applies to pure zinc. In practice, impurities such as lead or iron slightly lower the melting point, but for almost every application, you can simply calculate with 419.5 °C. Zinc therefore has a low melting point compared to most metals you cast in the workshop, which makes processing easier than with, for example, copper or iron.
Why does zinc have such a low melting point?
Zinc has a low melting point because the bonds between the zinc atoms are relatively weak compared to many other metals. Therefore, less energy is needed to change the metal from solid to liquid.
For comparison: aluminum only melts at 660 °C, copper at 1,085 °C, and iron at 1,538 °C. At 419.5 °C, zinc is well below that. This low melting point makes zinc a rewarding metal to start with if you are casting for the first time, as you don't need heavy equipment for it.
Melting and casting zinc in practice
Melting and casting zinc begins with a heat-resistant crucible, a heat source, and a mold. Because zinc becomes liquid at just 419.5 °C, a gas-fired melting furnace is more than sufficient.
You heat the zinc until it is just liquid and skim the oxide layer off the surface before pouring. Then you let the metal flow into the mold, in graphite or sand molds, depending on your workpiece. Work calmly and allow the cast zinc to solidify completely before opening the mold. Good preparation, with dry molds and clean zinc, prevents splashing and air inclusions in the final result.
The melting point of zinc alloys
The melting point of zinc alloys is often much higher than the 419.5 °C of pure zinc. As soon as you combine zinc with copper, or add it to a copper-tin alloy, the melting temperature shifts towards that of the other metals.
Is melting zinc dangerous?
Melting zinc is not dangerous, as long as you ensure sufficient ventilation and keep the temperature controlled. The risk lies in zinc fumes: if you heat zinc to around its boiling point, zinc oxide fumes are released that can cause metal fume fever.
This so-called zinc fever causes flu-like symptoms that usually disappear within a day or two. You limit the risk by keeping zinc just above the melting point, working outdoors or under good extraction, and wearing heat-resistant gloves and safety glasses. Stay as far below 907 °C as possible to minimize fume formation and work safely.
Melting zinc yourself with the right equipment
At Parrot Shopping, you'll find everything you need to get started with zinc and other non-ferrous metals: melting furnaces, crucibles, and complete melting kits that allow you to start all at once. This way, you always work with the right equipment at the right temperature, with the guidance you can expect from your guide in blacksmithing.
