1-18 BASIC KNOWLEDGE ABOUT PAINTS AND PAINTING Top coats are summarized as follows according to their characteristics: @ Very good 0 Good @ Good/fair Ј::,. Fair X :
Not good -20- ~ m Air-drying type Dual-component type Baked type NC acrylic lacquer CAB acrylic lacquer Acrylic urethane lacquer Quick-drying acrylic urethane Acrylic urethane Thermo- setting amino alkyd Thermo- setting acrylic Main components Nitrocellulose +acrylic resin CAB+ acrylic resin Nitrocellulose (or CAB)+ acrylic resin + isocyanate Acrylic resin + isocyanate Acrylic resin + isocyanate Melamine resin + alkyd resin Acrylic resin +melamine resin Type Single- component Single- component Dual- component Dual- component Dual- component Single- component Single- component Luster retention !::. 0 0 0 @ @ @ Yellowing-proof !::. @ @ @ @ @ @ Paint film texture !::. !::.
@ 0 @ @ @ Polishing Needed Needed Needed Not needed (needed for large area application or over blurred area) Not needed (needed over blurred areal Not needed (needed over blurred areal Not needed (needed over blurred areal Absorption-proof !::. !::. 0 @ @ @ @ Pencil hardness B-H F-H H- 2H H- 2H H- 2H H- 2H H- 2H Adhesion to old coats (baked coats) 0 !::. 0 @ @ Only requires compound- sanding 0 0 Solvent- proof Lacquer/ thinner X X @ 0 @ @ @ Gasoline !::. !::. 0 @ @ @ @ Repaintability 0 !::. Shrinkage, etc., tends to occur near putty or primer- surfacer !::. Shrinkage, etc., tends to occur during repainting @ @ @ @ Hiding power !::. !::.
@ 0 0 @ @ Workability 0 0 0 Isocyanate is poisonous @ Isocyanate is poisonous 0 Isocyanate is poisonous !::. Requires baking !::. Requires baking Drying time Required Until dry-to-touch 10 min at 20°C 10 min at 20°C 10- 20 min at 20°C 10 min at 20°C 20 min at 20°C - - For polishing 8 hrs at 20°C; 30 min at 60°C 8 hrs at 20°C; 30 min at 60°C 5 hrs at 20°C; 20 min at 60°C 5 hrs at 20°C; 20 min at 60°C - - - For open storage 8 hrs at 20°C; 30 min at 60°C 8 hrs at 20°C; 30 min at 60°C 16 hrs at 20°C; 30 min at 60°C 12 hrs at 20°C; 30 min at 60°C 48 hrs at 20°C; 60 min at 60°C 30 min at 140°C 30 min at 140°C