They are drained from the paint produced when it is applied on the instrument in a vertical position. And it can occur both in the background phase and in the finishing phase.
The reasons why it happens are the following:
- Low application viscosity due to excess solvent.
- Excess layer or product per hand.
- Use of slow solvents.
- Low room temperature.
- Inadequate regulation of the application (low air pressure, excessive product flow and insufficient distance of application).
- Inadequate flash-off time between coats.
Solutions to avoid it:
- Increase the viscosity of the application, thinning the paint less.
- Apply several thin coats.
- Use of faster solvents.
- Adjustment and regulation of the equipment (increase the air pressure, reduce product flow and increase the distance of application moving the gun away from the support).
- Respect the evaporation time between coats indicated in the paint’s technical data sheet and in accordance with the application temperature.
Repair:
- Sand the slack with P1200 sandpaper until the slack is eliminated
- Sand the surface with P1500- P2000 progressively
- Polish until the final shine is achieved.