Mottling
Also known as: striping, banding, shadowing, flooding,
floating, misting, precipitation, blooming, bloom, bleaching
Description : Occurs mainly in metallics, when the flakes float together to form a spotty or striped appearance.
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ORIGIN AND POTENTIAL CAUSES
» Unsuitable thinner or reducer for application conditions
» Materials not uniformly mixed
» Spraying too wet
» Holding spray gun too close to work
» Uneven spray pattern
» Incorrect spray PSI or gun setup
» Low shop temperature
» The flash time of the basecoat was too short before the clearcoat was applied
» Coat affected by wet or humid air/ weather. -
PREVENTION TECHNIQUES
» Select the thinner or reducer that is suitable for existing shop conditions and mix properly. In cold, damp weather,use a fasterdry solvent
» Stir all pigmented topcoats - especially metallics - thoroughly
» Use proper gun adjustments,
techniques, and air pressure
» Keep your spray gun clean (especially the needle fluid tip and air cap) and in good working condition
» Do not spray metallic basecoats too wet
» Keep spray gun parallel to panel
» Follow application recommendations
per the TDS -
REMEDY
» Allow color coat to set-up and apply a drier double coat or two single coats,depending upon which topcoat you are applying
» If the defect is only visible after the application of the clear, thoroughly dry the clear, sand and refinish