Mold making is a complex art with a lot of elaborate details and some terms that are unique to this craft only. Knowing the basics is important for navigating in the world of mold making and casting.
There are artworks and then there are molds and casts. Mold making and casting are truly intricate yet enjoyable crafts as they yield the most delightful results. Beginners need to know a lot of basic information before they can try their hand at making molds and casts. Let us start with details about the various terms that are commonly used by mold making artists.
- Model – Also called original, mother or prototype, this is the item or part that has to be replicated.
- Mold – This is a negative impression of the model which captures all the details that will be used to replicate the cast.
- Casting – This is the positive replica of the model that has been recreated to the exact shape, size and other details.
- Life cast – This is a casting of a live human person to recreate any part of the body with full three-dimensional details.
- Shell mold – This is a rigid mother mold which is created over a flexible mold to help it retain its shape.
- Pour mold – The mold is made simply by pouring the mold making material over the model and allowing it to cure.
- Brush-on mold – The mold is made by applying the mold material with a brush on the model in successive coats.
- Glove mold – This mold does not require a parting line. A small slit is used to easily remove the mold which fits like a glove over the model.
- Mold release – Also known as release agent, this is applied on the mold so that the cast can be easily demolded from the mold. Similarly, it is also applied on the model to allow easy disengagement of the mold.
- Mold box – This is a contained structure made around the model for making the mold. For small items, any container or even a cup can be used as a mold box.
- Undercuts – These are overhanging features or areas on the model that can cause difficulties in making the mold and cast.
- Parting line – This is a border created on the model when making the mold in two or more parts.
- Key – These are registration points which are created on the corresponding parts of multi-part molds. They allow the mold parts to easily line up together before making the cast.
- Spue – This is one or more hole made in the mold for allowing the casting material to be poured inside.
- Vents – These are passages made in the mold to allow trapped air to escape during the casting process, thus avoiding the appearance of air bubbles later on.
- Flashing – This is extra material left on the cast after the casting is complete, usually along the part line.
Once the users become familiar with the terms, they can move to finding out more about how to make a mold!