How many castings can I expect to get out of my rubber mold before it becomes unusable?

What you are really asking is, “what is the expected production life of my rubber mold?”.

First, we need to distinguish between the “production life” and “library life” of a rubber mold.

Library Life refers to how long a rubber mold will last in your “mold library”, just sitting on a shelf and not being used. Some mold rubbers last longer than others. Below is a chart giving you an idea of the library life you can expect from various mold rubbers:

Mold Rubber Approx. Library Life

Urethane (polyether based) ReoFlex, VytaFlex, Some PMCs - 25+ Years

Urethane (polyester based) PMC-724, PMC-726 - 1-7 Years (Moisture Exposure Dependent)

Silicone - Economy (tin cat) OOMOO Silicones - 1 Year

Silicone - Library Life (tin cat) Mold Max Series - 5-7 Years

Silicone - Platinum Catalyst Smooth-Sil, Dragon Skin - 30+ Years

Polysulfide FMC Series - 40+ Years

Latex - 10+ (With Proper Care)

Vinyl - 5+ (With Proper Care)

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.