Orange peel is common during summer construction, primarily caused by overly fast paint drying, improper spray pressure, or a mismatched thinner evaporation rate. This defect compromises both the coating's appearance and protective performance.
Orange peel appearance: The coating surface exhibits an uneven, bumpy texture resembling an orange peel, resulting in inconsistent gloss and reduced aesthetics. In severe cases, it compromises the coating's density, diminishing its corrosion protection performance.
Root Cause Analysis: High summer temperatures accelerate solvent evaporation in coatings, reducing the leveling time on the substrate. Improper spray pressure (too high or too low) causes uneven atomization. Incorrect thinner selection leads to rapid evaporation of fast-drying thinners at elevated temperatures. Excessive coating thickness in a single pass results in surface drying while the interior remains wet.
Preventive Measures: Schedule construction during cooler morning or evening hours to avoid peak afternoon heat; use slow-drying thinner to extend paint leveling time; adjust spray pressure to the appropriate range, typically 0.3-{1.5} MPa; apply multiple thin coats rather than thick layers; maintain an optimal distance between the spray gun and the substrate, generally 30-{30} cm.
Remedy: If orange peel occurs, wait for the coating to fully cure, then sand smooth with fine-grit sandpaper and reapply the topcoat.
CASUL offers summer-appropriate coatings and thinners, along with professional application guidance to help you achieve high-quality finishes.