I read a lot about defoamer used in GFRC. Do I need defoamer with VF-774?

No. While all polymers have a small amount of defoamer in them needed for the polymerization process, few, if any besides Forton® VF-774, add it at a level required to meet the requirements of GFRC. Forton® VF-774 was developed specifically for GFRC and adds enough defoamer to meet the requirements of GFRC related to high sheer mixing, pumping and spraying.

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.