Once production of the GFRC part is complete, it is recommended to cover the part in plastic for 12-16 hours during initial cure at a minimum temperature of 60? F. This prevents excessive evaporation of hydration water in hot, dry climates while polymer film forming takes place, ensuring a proper cure. It also helps to maintain the heat of hydration, known to accelerate initial strength gain. In colder climates, blankets and indirect heat can be used to ensure strength gain allowing demolding in 12-16 hours. GFRC should never be directly exposed to forced air heat or fans, which will result in craze cracking and drying shrinkage cracks. After demolding, GFRC containing Forton® VF-774 can be air cured.
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.
Smooth-On, Inc. will be closed Monday, May 29th in observance of Memorial Day, resuming operations Tuesday, May 30th.