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## Pinholes 

Pinholes are tiny holes, or groups of holes, that appear in the surface of the finish as a result of trapped solvents, air, or moisture. [Figure 8-15]  Examples include: 

• Contaminants in the paint or air lines. 

• Poor spraying techniques that allow excessively heavy or wet paint coats, which tend to trap moisture or solvent under the finish. 

• Use of the wrong thinner or reducer, either too fast by quick drying the surface and trapping solvents or too slow and trapping solvents by subsequent topcoats. 

If pinholes occur during painting, the equipment and painting technique must be evaluated before continuing. When dry, sand the surface smooth and then repaint. 

## Sags and Runs 

Sags and runs are usually caused by applying too much paint to an area, by holding the spray gun too close to the surface, or moving the gun too slowly across the surface. [Figure 8-16] 

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Other causes include: 

• Too much reducer in the paint (too thin). 

• Incorrect spray gun setting of air-paint mixture. 

Sags and runs can be avoided by following the recommended thinning instructions for the coatings being applied and taking care to use the proper spray gun techniques, especially on vertical surfaces and projected edges. Dried sags and runs must be sanded out and the surface repainted. 

## Orange Peel 

“Orange peel” refers to the appearance of a bumpy surface, much like the skin of an orange. [Figure 8-17] It can be the result of a number of factors with the first being the improper adjustment of the spray gun. Other causes include: 

• Not enough reducer (too thick) or the wrong type reducer for the ambient temperature. 

• Material not uniformly mixed. 

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