Somerset Regal L4-151 2.5L (1985)
Figure 1 - The Surface
FINISH ANALYSIS AND CORRECTION FOR THE
NEW CAR PREP TECHNICIAN
Introduction
When we refer to the "surface", we're talking about the entire finish - topcoats and undercoats - everything short of the bare body metal (Figure 1).
The immediate problem involved with breaking through the surface is that when the surface is broken (by sanding or by some other means) the bare
metal is exposed to air and moisture - and the possibility of future corrosion.
A second reason to avoid breaking through the surface is that there is always the possibility of a color mismatch in areas that are repainted.
Factory Painting Materials and Methods
There are two assembly line painting methods used, each with its own set of properties. One method uses thermo-flow acrylic lacquer finishes, while the
other uses thermo-set enamel finishes.
Figure 2 - Acrylic Lacquer Curing Process
Acrylic Lacquer
A thermo-flow acrylic lacquer finish is applied and reflowed in ovens at temperatures of approximately 325~ Fahrenheit, so the paint surface flow
together. The paint cures by solvent evaporation and the result is a level, glossy coat that requires little or no compounding (Figure 2). Because of the
heat involved, the acrylic lacquer cannot be reflowed after any plastic, rubber or glass is mounted on the car.