Umicore applies phosphates crystals on the zinc surface to pre-weather the zinc to the various surface colors. Crystals reflect light in a specific pattern and the appearance of pre-weathered zinc is directional. This means that two identical zinc samples will look differently if they are not oriented the same.
Umicore has placed arrows labeled “Rolling Direction” on the protective film to help orient the zinc. It does not matter which direction the zinc is oriented, but it is important to choose a direction then maintain that direction until the continuous zinc elevation plane is completed to avoid color variation.
The protective film should be removed from zinc panels upon completion of an elevation, all at the same time, to reduce the color variations due to one section weathering faster than another. The protective film should remain on the zinc no longer than 60 days after the completion of installation. Make sure that other trades will not contaminate zinc panels after the film is removed.
Color Management Process
Umicore has devised a system to help avoid drastic color variations if the area of coverage is larger than the amount that can be covered with one coil or one batch of zinc. It is called the Color Management Process that uses a range called the Y-Factor. The Y-factor ranges from 0 to 100: 0 is black and 100 is white. Each surface color Umicore offers falls within a specific range before it is allowed to leave the plant.
The range for ANTHRA-ZINC is 5 to 7 and the range for QUARTZ-ZINC is 22 to 25. A Y-factor variation of 0.5 is noticeable to the eye. Each coil and batch of sheets that leaves Umicore’s factory is marked with its Y-factor number. On large projects it is best to order and use material from the same production batch. If the project is too large for one production batch, group the zinc by Y-factor and production date. This color management process needs to be communicated to the installer to ensure that it is followed and to prevent color variations.
Note: Zinc is a 100% natural product, color variations may occur. Color match is not guaranteed.
- Non Marine Climates
Zinc is a natural building material that develops a dark grey patina that protects the surface from excessive metal removal rates. Technically, the patina, a layer of zinc-hydroxy carbonate, forms when the zinc material comes in contact with water and carbon dioxide from the atmosphere.
Color variations in QUARTZ-ZINC should not present a problem in the long run when the material is exposed to the atmosphere. The patina process will form a uniform color throughout the continuous zinc plan over time. This patina formation takes, on average ,between two to five years (except in dry climates where it takes longer). QUARTZ-ZINC TOC, ANTHRA-ZINC and PIGMENTO have a factory applied clear coat that will take longer to weather because the coating must first erode before the patina can form.
- Marine Climates (one mile from the Shore)
Zinc has been successfully used in marine environments for several decades.
In some marine climates, the salt in the air or water reacts with zinc to form zinc oxychloride, which has a whitish appearance. This white residue will normally be washed away by rainfall. However, in drier marine environments, it may remain on the surface.
Salt deposits will tend to develop near the shore on zinc soffits and other protected areas of a building, such as, but not limited to eave flashing, gutter underside etc. Water naturally condenses then evaporates from zinc surfaces, leaving some salts. Spray also contributes to this condition. While salt deposits are not harmful to the zinc, white marks appear over time when the deposits are not washed off by rain. This is a natural occurrence. Umicore Building Products USA, Inc. cannot be held responsible for the appearance of salt deposits on zinc surfaces.
In marine environment installations, Umicore expects that the zinc material will patina and not retain its original color and hue. Please consult your local VMZINC representative for more information.