How can I make my Mold Max tin silicone rubber cure faster?

Article courtesy of Smooth-On, Inc.

Unlike platinum silicone rubbers (Dragon Skin® or Smooth-Sil® products) which can be heat cured, tin-cured silicones do not respond to heat. Your only option is to add a chemical to accelerate the silicone.

Adding Accel-T® dramatically reduces the working time (pot life) and demold time of Mold Max® silicone rubbers. A small amount will speed up the material considerably. Accel-T® should be added to Part B by weight and thoroughly pre-mixed before adding Part A.

Very Important – Accel-T® will reduce the library life of the cured rubber mold in proportion to the amount used. For example, Mold Max® 30 normally has a library life of at least 5 years. Using 1% Accel-T® will reduce the library life to less than 1 year.

Note: Accel-T® does not have an effect on platinum-based silicones.

The following offers percentages of Accel-T® and the corresponding effects on pot-life and demold time:

  Mold Max® 10Mold Max® 20Mold Max® 30Mold Max® 40
0.2 %
Accel-T®		 Pot Life 20 min. 15 min. 15 min. 15 min.
Cure Time 3 hr. 2 hr. 3 hr. 2 hr.
1 %
Accel-T®		 Pot Life 10 min. 5 min. 7 min. 8 min.
Cure Time 1 hr. 1 hr. 1 hr. 1 hr.

Note: Full chart can be found on the Accel-T® Technical Bulletin.

Disclaimer

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.

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