1.Too fast-drying base coat
2.Too thin paint film
3.Using too coarse sandpaper
1.Add slow-drying solvent, such as Butyl Celloslve or Solvesso 150 to delay the drying time.
2.Add paint compounds and make several thin spray applications according to the instructions.
3.The higher number grits of sandpaper, the finer it will be. Sandpaper of 1000 grit is generally recommended.
4.Sand the surface in horizontally one direction. Do not sand back and forth.
The good finishing surface appearance is varied by the sanding pressure.
Even and smooth sanding are necessary for the whole piece of works.