Panel edge staining is a naturally occurring problem that occurs to anodized aluminium

Aluminium

Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

 and stainless steel

Stainless steel

In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....

  paneling and facades. It is semi-permanent staining that dulls the panel or facades surface (in particular the edges of the paneling), reducing the natural luster and shine produced by the anodizing processes used on the aluminium. Panel edge staining may also appear on powder coated aluminium, painted aluminium, stainless steel and titanium surfaces.

Causes

Panel edge staining is the by-product the build-up of dirt and pollution. It is especially more noticeable on buildings using metallic facades in Asia, and regions close to the equator

Equator

An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....

 (such as Florida

Florida

Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

 or South East Asia), as higher rates of air pollution

Pollution

Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...

, high levels of humidity and consistent rainfall encourage panel edge staining to develop.

The unique top to bottom stain pattern of panel edge staining is caused when the build-up of dirt and pollution is washed from the higher panels to the lower panels of a surface by natural precipitation

Precipitation (meteorology)

In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...

.

External links

• Issues associated with Aluminium window frames