Skip to content

Back to catalogue

Previous

3 / 12

Next
03

Coating

Mottling / clouding

Lighter and darker spots in metallic or pearl paint - the effect of irregular "clouds" visible when viewed from different angles.

Mottling / cloudingcorrect base coat applicationpoor application

Cause

  • Thinner too fast - the varnish dries too quickly and the metal flakes do not have time to arrange themselves parallel to the surface
  • Inappropriate thinner for the product - poor working viscosity confuses the flakes during application
  • Spray pressure too high - metal flakes are "shot" in different directions instead of laying flat
  • Wrong spray gun or nozzle not suitable for base coat
  • Too thick a base - too much material at once does not allow the petals to stabilize
  • Evaporation time between base layers is too short
  • Poor overlap between spray strips - inconsistent amount of material on surface
  • Incorrect spraying technique for droplet coatings - evaporation time too short, pressure too high or too many layers at once

Prevention

  • Select the diluent in accordance with the technical data sheet, taking into account the cabin temperature and air flow
  • Use the appropriate gun and nozzle recommended for the base coat
  • Follow the recommended spray pressure - metallic bases are usually lower than clear ones
  • Apply the base in thin, even layers with proper overlaps
  • Observe evaporation times between base coats
  • When using droplet coatings, use the appropriate spraying technique in accordance with the technical data sheet

Repair

  • Determine the cause before repairing - check the diluent, pressure and spraying technique to prevent the error from recurring
  • Sand the base layer dry with P600 or wet with P1000 - do not sand to the primer
  • Before reapplication, test on a test plate with the selected diluent and gun settings
  • Reapply the base coat using the appropriate thinner for the current temperature and airflow in the cabin
  • Observe the recommended spray pressure and gun-to-work distance
  • For colors with a metallic effect, apply the last layer of the so-called base. "finishing layer" from a greater distance and lower pressure - orients the flakes parallel to the surface
  • Coat with clear after the base has properly evaporated