Painting Defects

Orange Peel

This defect gives the paint finish the rough appearance similar to the outside of an orange. The defect is found in spray painting and is generally due to having the wrong solvent. It can also be due to an incorrectly adjusted spray gun.

The solution is to use the manufacturers recommended thinner and to adjust and use the gun correctly.

Peeling

Peeling is simply another type of flaking where the amount of paint film removed is greater.

Pin holing

The defect is the appearance of small holes in dried paint film. The problem is most probably caused by too thick a coat trapping solvents into the film, or by air bubbles. The defect may be due to not cleaning the surface before painting, using the wrong solvents in spray painting or incorrect air pressure. The problem can be solved by addressing the above causes.

Poor Flow

Poor flow can manifest itself in two ways: if the paint is too thick and will not flow out this will show up as a rough surface or orange peel where the surface resembles the skin of an orange; if the paint flows too much the result will be runs, sags and wave formation. This defect is remedied by proper formulation and when thinning the paint to use the right solvent and the correct amount.

Poor Hiding or Lack of Opacity

Opacity is the ability of a paint film, when applied to a given surface, to hide or obliterate the surface or the undercoat. Poor hiding power can be due to too thin a coat being applied or to the formulation using a poor quality pigment.

Runs and Sags

As the name suggests this is the formulation of runs or sages on the finished paint film.

The defect can be caused by a number of things:

• Too thick of a film.
• Too much thinners.
• Not allowing the first coat to dry before applying the top coat. 

Posted in: BGAS Grade 3/2,Orange Peel,Painting Defect and Definition,Painting Defects,Peeling,Pin Hole,Pin Holing,Poor Flow,Poor Hiding or Lack of Opacity,Runs and Sags