Uneven Gloss (Flashing)
Uneven gloss is deterioration of the paint film, resulting in excessive or rapid loss of gloss or sheen of the topcoat. Uneven appearance of a coating's gloss, sheen or luster is also an indication.
- Use of a gloss alkyd/oil-based paint or solvent-based epoxy in areas of direct sunlight.
- Heavy dew, moisture or condensation on paint during drying.
- Temperature fluctuations during drying.
- Painting over a porous surface.
- Paint applied at uneven film thickness (i.e., lapping).
- Insufficient film build (applying paint too thinly).
- Use of interior paint outdoors.
Exterior alkyd/oil-based paints and solvent-based epoxies will chalk, giving the appearance of loss of gloss. Washing the chalk off should return most of the original sheen, but it will likely chalk again. If this is unsatisfactory, recoat with an acrylic following all label directions.
Bare surfaces should be primed/sealed before applying the topcoat to ensure a uniform surface.
Spot-prime any patched areas to try to even out the porosity of the surface.
Often, applying an additional coat will even out sheen irregularities.
Thinning any touch-up coating may help it blend in better and match the sheen of the surrounding area.
Follow label directions for the proper environmental condition for application, appropriate spread rate and applicator and product use.