GL Optex Super Build 4:1 Primer – Color-Changing High-Build Polyester Primer (Gallon Size)

GL Optex Super Build 4:1 Primer is a professional-grade, high-build polyester primer that features innovative color-change technology for optimal sanding readiness. This unique formula applies pink and dries gray, visually indicating when it’s ready to sand—eliminating guesswork and improving workflow efficiency. Ideal for automotive repair and refinishing, it offers exceptional filling capability, making it perfect for leveling out bodywork and minor surface imperfections. Engineered for use on metal, fiberglass, and properly prepped surfaces, this 4:1 primer sands easily to a smooth, paint-ready finish. With its excellent adhesion, fast drying, and color-shifting innovation, GL Optex Super Build is a smart solution for achieving flawless, high-quality finishes in professional body shops and custom paint environments.