Flexible Silicone Molds vs Rigid Molds

The geometry of the pattern is an important factor when choosing a molding material. If the pattern has undercuts, or is a very intricate shape, a flexible silicone mold is recommended. The flexibility of the silicone will allow you to stretch it over the undercuts in order to release the casting. This is not to say a rigid mold can’t be used; however, you would most likely need to construct multi-piece mold with more than 2 or 3 mold sections. This is more work and effort than creating a silicone mold.

Silicone molds are great for short production runs. However, silicone molds have a life span. Some of this depends on the casting material being used, the geometry of the master and quality of the silicone. The life of a silicone mold can be extended by using a mold release like our E302 or E236. In certain cases, silicone may not be the most cost-effective material for long production runs. Rigid molds don’t have that limitation if properly maintained. Both Silicone and Rigid molds have pros and cons, and it comes down to what you are looking to get out of the mold.

Silicone molds, great flexibility, easy to demold, excellent reproduction of fine details and finishes, limited life.

Rigid molds, outstanding durability, structural strength, cost effective, ideal for foam castings, can be difficult to demold.