Defects in car paint spraying ----Shrinkage/Fish Eyes
1. Description:
There are a large number of crater-shaped voids or pits ranging from pinholes to 1cm in diameter on the surface of the paint film. Usually, the large-sized pits appear individually, while the small pits appear in sheets with lesser densities. Small impurity particles are generally found in the center of the dent.
2. Reason:
The surface tension of the paint changes.
1) There are organic compounds containing silicon in the painting environment or on the surface of the substrate, even a small amount of silicon is enough to cause shrinkage craters in the paint film.
2) Other sources of contamination, such as: grease, soap clumps, detergents, dust, wax or oil from the spray gun, etc.
3) The primer contains mismatched ingredients.
4) The steam in the painting room is saturated.
3. Prevention:
Thoroughly remove the silicon-based polish from the sprayed surface. It is forbidden to use silicon-based polishes in the spray shop.
Prepare the surface for spraying as follows:
Thoroughly clean the substrate surface with a dewaxing degreaser. Do not allow the cleaning agent to evaporate and dry, but dry the surface of the substrate with a clean dry cloth, only once per dry cloth. Before grinding, the surface of the substrate should be cleaned, and the cleaning area should be larger than the area to be polished. After grinding, the abrasive dust must be removed from the surface of the substrate, and then the substrate surface can be cleaned with a cleaning agent before painting. Make sure that the spray gun and compressed air equipment are well maintained.
4. Repair method:
First remove the paint layer from the defective area completely, then after treating the substrate surface according to the above procedure, repaint it.
