Runs
Also known as: overloading, curtains, gun spits, sags,
sagging, drips
Description:Heavy application of sprayed material that
fails to adhere uniformly to the surface.
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ORIGIN AND POTENTIAL CAUSES
» Incorrect spray viscosity, flash time,technique, or film thickness
» Defective or incorrect spray gun set-up
» Wrong thinner or reducer
» Too much thinner or reducer
» Inaccurate lighting in the spraybooth, painter is unable to apply coating correctly
» Surface contamination by oil, grease, etc.
» Shop, surface or paint is too cold
» Low air pressure (causing lack of atomization), holding gun too close, or making too slow a gun pass
» Incorrect technique of application
» Paint drops from the gun -
PREVENTION TECHNIQUES
» Allow vehicle surface to warm-up to at least room temperature before attempting to refinish
» Try to maintain an appropriate shop temperature for paint areas
» Use proper gun adjustment, air pressure, and techniques
» Allow sufficient flash-off and drying time in between coats
» Select proper thinner/reducer
» Read and carefully follow label or product data sheet instructions
» Select suitable thinner/ reducer
» Install accurate lighting in spray booth
» Ensure that the spray gun is in good
working order. -
REMEDY
» Wash off the affected area and let dry until you can sand the affected area to a smooth surface and refinish. For solid colors and clearcoats, sanding and polishing is recommended. In the case of a basecoat, refinishing after sanding is necessary.