Crater-forming
Crater-forming
Microtome cut from above
Cross section of microtome cut
Description of the defect
Irregularly confined wetting defects to the lacquer in the substrate caused by different surface tensions in the lacquer and substrate.
Cause of the defect
- substrate contaminated with oil or fat.
- defective seals in the airless sprayer.
- Contact with unsuitable hand creams/rubber gloves/conveyor belts
- tools or, as may apply, additives containing fat or silicon.
- Dirt in the lacquer .
Defect solution
- The source of the defect must be remedied.
- Where the damage is severe, sand the surface down to the substrate and, if required, reconstruct the surface by adding anti-silicon ZD 385 (ZD 3985).
- Where light craters form, sand the surface down with 320 grain, apply a very thin mist of the coating used as before and after it has been allowed to dry for a short period, finish with 1 x thin coat of suitable lacquer in order to achieve even levelling .