Silicone Molding

What is silicone molding?

Silicone molding is a readily available and relatively simple method of creating a negative, which can be used to cast multiple items with decent accuracy. These molds are usually flexible. Most silicone molding kits come with two parts, which are meant to be mixed at a specific ratio to yield a room temperature curing silicone mold. There are various price points for different molding kits that have different properties, for example shrinkage and a longer library life. Most silicone molding kits do not need a release agent.

To make a silicone mold, you need a physical copy of the item. The process is fairly simple and only requires the user to mix the two parts in a specific ratio, place the item into the container used for the mold, and wait for the mold to cure. After it has cured, the user can cut the mold in half and peel it off the item, creating a negative that can be used for repetitive casting.


Here are some basics on how to use silicone molding with tutorial videos.

When deciding on whether or not to use silicone molding, a few questions to ask yourself are:

  • Do I need to make more than one identical part?
  • Of what material do I want my part to be cast?
  • What kind of finish do my parts need?

A silicone mold is (typically) the negative impression of a positive 3D object. Creating a negative mold allows you to produce more models relatively quickly. Silicone molds can be used to cast a variety of materials, including polyurethane, polyester and epoxy resins, polyurethane foam, plaster, wax, concrete, low melting metals, and more. Usually, silicone molds are quite durable, but depending on the material you are casting with, damage can occur to the mold and therefore create imperfections on the surface of the mold the more it is used. This is not desired if you need many parts, and all of them need a very high resolution finish.

Silicone molding is a relatively slow manufacturing process once the mold is made. Depending on the material being used to create the model, it could take days for the part to set properly before it is safe to remove from the mold. However, creating the mold can be a relatively fast process, only needing a few hours to set (this time varies depending on the specific silicone you choose to create the mold).

Silicone molding on campus

The silicone molding process is simple, but involves some potentially hazardous materials.  The process should be performed while wearing a respirator or under a fume hood.

The materials science and engineering department occasionally employs silicone molding and has the necessary equipment to maintain safety.  There are a variety of vacuum chambers in the materials science and engineering lab to degas the silicone before pouring the material into a mold.  This degassing procedure is used when a higher surface quality is desired than found in a standard silicone mold.  For information about using the materials science and engineering facilities for silicone molding, you may contact the lab supervisor, Bill Pingitore, at:

The school of art also has silicone molding capabilities.  For more information regarding facilities, you may contact the department’s s sculpture technician, Phillip Scarpone, at: