Bondo Professional Gold Filler is adhesion promoted for double-coated galvanized steel used on newer vehicles, plus aluminum, fiberglass, SMC and more. Advanced 3M resin technology makes it extremely easy to mix with the included hardener, and it applies smoothly and is easily sandable in minutes. The result: Simpler professional-grade auto body repairs in garages of any size.Bondo Professional Gold Filler is adhesion promoted for double-coated galvanized steel used on newer vehicles, plus aluminum, fiberglass, SMC and more. Advanced 3M resin technology makes it extremely easy to mix with the included hardener, and it applies smoothly and is easily sandable in minutes. The result: Simpler professional-grade auto body repairs in garages of any size.