Delft Clay/Sand Casting FAQ
What is sand casting?
Sand casting is the term given to describe a technique used by jewellers and other metal workers to replicate existing items using a mold made of sand. The original item or ‘master’ is pressed into the sand to create a void into which molten metal is poured. Once cooled the item can be removed from the sand to be finished.
What can be cast?
Practically anything that fits within the mold can be cast. I have cast shells, rings carved in wax, buttons, Lego figures, small twigs, etc. I’ve made pendants using casts of existing jewellery pieces.
Is it just normal sand?
Sand casting is done using specific sand mixtures. There are at least two brands; Delft Clay and Petrabond, I use Delft Clay which is sand mixed with an oil that helps it to hold shape and heat. Delft Clay uses fine sand so it is possible to pick up a lot of detail from the master. As molten silver pours into the mold there is smoke and usually a small flame, these are both short-lived.
What can’t be cast?
Anything that could not withstand the pressure of the mold making process which involves being pressed into the sand or having the sand heaped over it and compressed by a hammer. There is always the option of creating a wax replica and some jewellers can even 3D print the master.
What are the shortcomings of casting?
Molten silver shrinks as it cools so even though the imprint was the same size as the master, the cast item with be around 10% smaller. Some items use a lot of silver that can end up being heavy and expensive.
Can I see you cast something?
Yes, I have many videos of delft clay and cuttlebone casting on Tiktok, you can follow me here: https://www.tiktok.com/@saras.art.australia
