No. Not all white, milky polymers are created equal. Even though both VF-774 and VF-812 are all acrylic co-polymers, they are not identical chemically and provide different finished properties. VF-774 will not cross-link as the VF-812 does, so it will not provide the moisture resistance of VF-812.
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.