Use a fast-dry thinner or reducer, especially when the material is sprayed too dry or at an excessive pressure. It can also occur because the wrong thinner or reducer was used incompatibility of materials. If the pressure is great enough, blisters form. When the finish is exposed to the sun (or abrupt changes in atmospheric pressure), moisture expands and pressure builds up. This can also occur in unison with excessive film thickness we are in a rush and don't allow sufficient drying time and apply too much material. Also, insufficient drying time between coats or too heavy application of the undercoats may trap solvents, which escape later and blister the color coat. This happens when wet sanding polyester and applying topcoat without enough time for the water to evaporate. It's the direct result of tiny specs of dirt left on the surface and these dirt particles act like a sponge and retain moisture. And what none of us wants to hear but we know happens, improper surface cleaning and preparation-poor location or prep of the work area such as contamination of compressed air lines oil, water, or dirt in lines. It can also result from the ambient humidity too high. It is generally the result of leftover sanding water in the corners, edges, crevices, or below any other art on the final paint. They also have very good application and hiding properties, which minimize the tendency to apply too thick a coat of paint.Sometimes known as moisture blisters, blisters, bubbling, blowing, or bubbles, this hiccup will manifest itself as bubbles or pimples appearing in the topcoat.Quality paints have a higher solids content, which reduces the tendency to mud crack.This type of paint is likely to prevent recurrence of mud cracking, because it is relatively more flexible than alkyd paint, oil-based paint and ordinary latex paint.Mud-cracked areas can also be repaired by sanding the surface smooth before repainting with a top quality latex paint.Prime and repaint, using a top quality latex paint.Remove coating by scraping and sanding.Use recommended application techniques with suitably formulated products.Only apply the recommended coating thickness.Paint is allowed to build up in corners upon application.Paint applied too thickly, to improve inherent poor hiding (coverage) of a lower quality paint.Paint applied too thickly, usually over a porous surface.

Generally over application of heavily pigmented primers such as inorganic zinc silicates or water based coatings, although can occur with other over thick systems.On metallic substrates, this can also be an indication of a growing corrosion or stain which was not properly rectified during sanding and scraping off of irregularities. It is common along corners where there might be an accumulation of paint. This phenomenon occurs when an over coating is applied on curved surfaces and unprepared surfaces. Mud cracking is a coating flaw that occurs on the surface of a wall that looks similar to deep and irregular mud cracks on the surface of the earth. Cracking comes in several forms, fro minute cracking to severe cracking. Paint coatings with visible cracks which may penetrate down to the substrate.

Fisheye paint defect