Which primer formulation is designed specifically to enhance surface build?

The primer formulation specifically designed to enhance surface build is epoxy primer. Epoxy primers are known for their excellent adhesion, durability, and ability to create a thick layer over a substrate. This characteristic is particularly useful when preparing surfaces for painting, as it allows for better filling of imperfections and a smoother finish once topcoated.

Epoxy primers often contain a high solids content, which contributes to their thick application. This makes them ideal for automotive refinishing and industrial applications, where a robust base is desired to withstand harsh conditions. The curing process of epoxy also helps in forming a strong bond with subsequent layers, leading to a resilient and long-lasting finish.

In contrast, other types of primers mentioned have distinct purposes. Shellac primers are mainly used for sealing stains and preventing bleed-through but do not provide significant build-up. Acid etch primers are primarily utilized on non-ferrous metals to promote adhesion, but they do not enhance surface build significantly. Enamel primers serve to provide a smooth foundation for enamel paints but are not specifically formulated for maximizing surface build as epoxy primers are.