Air bubbles develop in a clear coat when the finish has been hastily applied or when the object hasn't been properly prepped before clear coat application. These air bubbles, according to Paint Scratch website, are sometimes called fish eyes. Spraying or brushing the finish on quickly or applying an excessive amount of clear coat that pools on the object's surface, creates bubbles as the air trapped between the clear coat and the object rise to the surface. Debris on the surface of the object, such as water or oil, will also cause bubbles. Spray or brush clear coat onto an object in even, left to right strokes. Never shake or stir clear coat before application to avoid bubbles.
Clear coat finishes in the wet stage will attract lint, dust and other forms of airborne debris. Garages and workshops are particularly prone to floating particles that will stick to wet, clear finishes. When applying a clear coat finish to a project, ventilation is an absolute must to avoid inhalation injuries, but choose a workspace free of wind or gusts of air, such as under a heat or air conditioner vent, to avoid unnecessary particles from adhering to the wet surface of your clear coat finish. Once dry, there's no effective way to pick these tiny annoyances out of the clear coat.
Clear coat finishes that yield white streaks, hazy, murky or cloudy results are usually due to the amount of moisture in the air while the clear coat was being applied and while the finish was drying. Paint Scratch website recommends applying the clear coat on a day with a 50 percent or lower humidity level to avoid cloudy results. Always allow one coat of clear finish to dry completely before brushing or spraying an additional coat. The base coat must dry thoroughly or the subsequent layers of clear finish will remain soft or spongy and will assume a murky appearance.