CSLB C-33 Painting & DecoratingCoating ApplicationMedium
A painting contractor is applying a fast-drying, solvent-borne epoxy coating to a steel beam in a fabrication shop. The painter notices that some areas appear rough and textured, with a dull finish, especially where spray passes overlap or at the edges of the spray fan. This defect is known as:
- ASagging
- BFisheyes
- COrange peel
- DDry spray / Overspray
Show answer & explanationAnswer & explanation
Correct answer: D. Dry spray / Overspray
Dry spray or overspray occurs when atomized paint particles dry in the air before reaching the substrate or a wet film. This results in a rough, textured, dull finish because the dried particles do not coalesce properly. It's common with fast-drying, solvent-borne coatings and improper spray technique.
Why the other options are wrong
- A. Sagging is the downward flow of a wet film due to gravity, resulting in uneven thickness and drips, not a rough texture.
- B. Fisheyes are circular voids in the film caused by contamination, not a general rough texture.
- C. Orange peel is a textured surface resembling an orange skin, caused by poor flow, but typically a more uniform texture than the localized roughness of dry spray.
Dry Spray / Overspray
A coating defect where atomized paint particles dry in the air before reaching the substrate or a wet film, resulting in a rough, dull, and textured finish.
- Common with fast-drying paints or high temperatures/airflow.
- Caused by spraying too far from the surface or insufficient atomization.
- Leads to poor adhesion and aesthetics.
Memory trick: Spray too far, dry in the air, a rough coat, no repair.