PAINTING TIPS FOR
GALVANIZED AND PHOSPHATIZED SHINGLES
Prior to
manufacturing, the base metal used in our galvanized and phosphatized
shingles is “chem.-treated” at the mill. This is done to protect the metal
from rust prior to installation. Because of this chem.-treat process a
typical metal bonding primer is not the best choice for a primer (though it
is better than not using a primer at all.) The bond needs to be established
between the primer and the layer of chem-treat on top of the galvanized
metal.
One company that has a
commercially available product is Valspar. Valspar offers both cleaning and
priming procedures and products that can be purchased at a local Lowe’s
store.
Below are the Valspar cleaning recommendations and a brief
overview of the product. Additional information can be found on the label of
their Glossy Surface Primer.
1) Power
washing with a simple detergent cleaning solution that consists of:
2) If
mildew is apparent the above detergent solution should be modified as
follows:
-
1/3 cup detergent
(Tide or equivalent)
-
2-3 cup
tri-sodium phosphate (Solex or equivalent)
-
1 quart 5% sodium
hypochlorite solution (Clorox or equivalent)
-
3 Quarts of water
3) A
very important step in any cleaning procedure is to thoroughly rinse with
clean water
The product
recommended by Valspar is an oil-based primer that is known as their Glossy
Surface Primer and is part of their American Tradition line of paints. This
primer will adhere to clean, glossy surfaces without the usual sanding or
de-glossing requirements of ordinary primers. To ensure
greater adhesion, these surfaces may be sanded or
deglossed, if desired.
These are simply painting
tips recommended to us by a few
metallurgists and paint specialists. Regional climates vary greatly so seek
a local paint specialist for more advice. |
