1. Putty residue
In the car refinishing and painting occasions, the parts where the putty is scratched will produce scars or loss of gloss.
Etiology
1) Insufficient grinding of putty parts.
2) The putty part is not coated with primer, and the paint absorption of the putty layer is large, or its color is different from that of the primer layer.
3) The putty used has a large shrinkage and will continue to deform after curing.
prevention
1) The putty parts should be fully polished and the edges should be smooth.
2) Apply a sealing primer on the putty part or spray a top coat first to seal the edge.
3) Choose putty with low shrinkage, such as nitro putty, which has high shrinkage and is only suitable for filling defects such as sand holes and scratches.
2. Repair spot marks
The gloss and hue of the repaired part and the original painted surface are different.
Etiology
1) The gloss and color of the repair paint are different from the original paint, or the repair paint has poorer aging resistance (such as weather resistance) than the original paint.
2) The part to be repaired is poorly polished resulting in uneven gloss.
3) Caused by partial repair.
prevention
1) The color (relevant instrument: color difference meter), gloss and aging resistance of the repair paint should be as close as possible to the original paint, and it is recommended to use the original process and original paint.
2) The parts to be repaired are carefully polished.
3) The repaired surface should be extended to the obvious geometric dividing line.
Three, brush marks, roller marks
When applied by brush and roller, uneven brush and roller marks (or streaks) remain on the dry film.
Etiology
1) The leveling of the paint is poor, and the pigment content in the paint is high.
2) Brushes and rollers are too hard.
3) The temperature is low.
4) The solvent evaporates quickly.
prevention
1) Choose paint with good leveling property.
2) Apply a suitable brush or roller according to the characteristics of the paint used.
3) The ambient temperature should not be lower than $%&.
4) Use a solvent with a high boiling point and slow evaporation.
5) Quick-drying paint should be sprayed, not brushed or rolled.
Four, no spot printing
Spots with reduced gloss appear on glossy painted surfaces.
Etiology
Contamination by atmospheric ammonia (a characteristic defect of oil-based paints).
prevention
Eliminate ammonia and its sources from the atmosphere.
