Tiger stripes, those dark vertical stripes that appear on aluminum rain gutters. Customers sometimes call us about these dark stripes that will not wash off. The first assumption is that the paint has gone bad. This is usually not the case.
We live in an industrial age where we have a constant source of particles in the air like dust, pollution, acid rain, pollen, general dirt and various other contaminants.
These various particles as well as atmospheric conditions cause condensation and the staining of various surfaces (especially gutters). These harsh contaminants “eat” away at the finish of your gutters day after day leaving a surface condition perfect for staining (blackening) and the classic striping called “Tiger Striping”.