The tin-zinc alloy is applied to both sides of FreedomGray sheets and coils. This ensures complete coverage and eliminates voids.
    A pre-weathered (painted) finish is factory-applied to FreedomGray, to reduce initial reflectiveness, provide a natural, weathered appearance and minimize the possibility of "white rust" corrosion during storage and transit.
    The paint is applied in a "semi-controlled" manner to assure that some of the surface is covered and some is not. This may create noticeable variations between panels- non-uniform patterns, textures, lines or shading. The uncovered tin/zinc alloy begins to darken immediately upon exposure, while covered areas undergo little or no color transformation until the paint is removed through weathering.
    It is important to understand that the paint is a transitional phase only. It is NOT FreedomGray's final color or aesthetics.
    Over time, as weathering breaks down the paint, and exposes the alloy, the initial differences fade away. Environmental conditions and severity of exposure dictate how long this will take. For roofs, most paint is usually removed within 12 to 18 months, while vertical wall panels may take longer.

FreedomGray vs. Zinc:
A revealing comparison.

    When a durable gray architectural metal roof is called for, FreedomGray offers numerous advantages over zinc. Like all architectural copper, FreedomGray is easier to form, simpler to install and more durable in the most environmental conditions. These are the facts:

More versatile forming- At temperatures below 45 degrees F, zinc becomes brittle and may break or split when bent, formed or subjected to stress or loads. All coppers, including FreedomGray, can be formed, installed and subjected to sub-freezing temperatures with no adverse effects.
    Sharp, zero-radius bends that are typical with all architectural metal work, can stress zinc to the point that it cracks and splits. Expansion movement caused by daily and seasonal temperature changes can aggravate minor splits and make them "run" or grow.
    FreedomGray can be formed and installed with the same bends as plain or lead-coated copper.

Less restrictive installation- Moisture on the reverse side of zinc can cause severe rapid corrosion. In extreme conditions it can "rust through" in less than a year. To avoid this problem, the underside of zinc must be ventilated- installed above the roof deck. This difficult, costly installation is not necessary with

copper, including FreedomGray, which can be applied directly over roof decks.

Greater durability- Ice dams in valleys and along eaves are a common winter occurrence in much of the country. Water trapped behind these dams can (and does) penetrate locks and seams.
    With zinc roofs, this can lead to "underside corrosion." Moisture trapped on the underside of copper, on the other hand, has no negative effects, making FreedomGray the better choice for long term durability.

Physical properties- Properties of sheet zinc (coefficient of thermal expansion, tensile strength, creep rate, etc.) depend upon temperature and direction of rolling. The above chart compares the coefficient of thermal expansion for zinc and copper.

Soldering- Zinc anneals at 212 degrees F and melts at 784 degrees F. Standard solder begins to flow at 420 degrees F. As a result, soldering changes the grain size of zinc (anneals it) and weakens it at the seam. If too much heat is applied, a hole can easily be burned through zinc.
    The melting point of architectural copper is 1,981 degrees F. At 700 degrees F, it takes almost an hour for copper to begin to anneal. FreedomGray is soldered similar to plain and lead-coated copper.