Clearly using the same formula and same color code, yet the repaired area looks "noticeable" — this is the most common embarrassment in repair work. Color consistency depends not only on the formula, but is also influenced by application variables. This article breaks down these invisible influencing factors.
I. Film Thickness and Spray Angle
The orientation of aluminum powder in metallic paint within the paint film changes with film thickness: different film thickness results in different specular-to-diffuse reflectance ratios, causing color shift. Inconsistent spray gun angle/distance leads to local film thickness drift, producing light and dark bands on the entire panel.
II. Flash-off Time and Clearcoat Refraction
- Flash dry: Insufficient intercoat flash drying, solvents trapped, abnormal aluminum powder settling, color phase shift.
- Clearcoat refraction: Changes in clearcoat thickness/refractive index alter the "filter" over the basecoat, causing visual color shift.
III. Temperature and Humidity
Temperature and humidity affect solvent evaporation rate and leveling: high humidity and low temperature easily cause blushing and poor leveling; high temperature causes fast solvent evaporation and premature orientation of aluminum powder. The same formula sprayed in different environments will show systematic color shift.
Summary
Color consistency is jointly determined by formulation and application. Any drift in film thickness, spray gun angle, flash-off time, clearcoat refraction, or temperature and humidity can cause color difference. The control method is to match the panel with the same process and environment, and use blend spraying to soften the boundaries.
Frequently Asked Questions (FAQ)
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