To ensure an ultra smooth surface, use Transtar’s pit fill spot putty. It is a single component polymer based system that air dries to a sandable, durable finish in minutes!. Designed for use in filling scratches, pinholes, low spots, blemishes, sanding marks and other surface imperfections. Pit fill spot putty has excellent adhesion to bare metal, galvanized, aluminum and over other properly prepared existing finishes. Once cured, it can be sanded to a featheredge and accepts virtually all paint finishes. It features minimal shrinkage and an ultra-smooth consistency.