How long should I keep a material under pressure when pressure casting?

Article courtesy of Smooth-On, Inc.

We recommend keeping a liquid rubber or plastic under pressure for the duration of its cure or handling strength time. Any bubbles that may have been collapsed by the pressure can possibly reappear if the material is too soft when you release the pressure.

Pro Tip: Look for a pressure chamber that can hold pressure (by closing valves, etc.) without leaving the compressor on.


This FAQ article is offered as a guideline and offers possible solutions to problems encountered during mold making and casting. No warranty is implied and it is up to the end user to determine suitability for any specific application. Always refer to the provided Technical Bulletins (TB) & Safety Data Sheets (SDS) before using any material. A small scale test is suggested to determine suitability of any recommendation before trying on a larger scale for any application.