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STAINING PROBLEMS WITH ANODIZED WINDOW FRAMES

 

AS A GC I RECENTLEY HAD ANODIZED WINDOW FRAMES INSTALLED IN A NEW MASONRY BUILDING. THE MASONRY WAS WASHED WITH WATER ONLY PRIOR TO FRAME INSTALLATION. THERE WERE NO ADMIXTURES TO THE MORTAR OTHER THAN COLOR. AFTER ONE HEAVY RAINSTORM THE FRAMES ARE DISCOLORED (ALMOST LIKE A RAINBOW EFFECT) AND IN TWO LOCATIONS THE ANODIZING IS COMPLETLEY GONE TO THE BARE METAL WITH A WHITE RESIDUE LEFT ON THE FRAME.

THIS IS THE THIRD TIME THIS HAS HAPPENED . IN THE PRIOR TWO CASES WE ENDED UP PAINTING THE FRAMES. IN THOSE INSTANCES WE HAD USED EITHER AN ACID WASH OR AN ADMIXTURE TO THE MORTAR BECAUSE OF TEMP OR BOTH. WE DID NIETHER IN THIS CASE .

WHAT COULD BE THE CAUSE? IT HAS COST MY COMPANY OVER $20,000 TO CORRECT THE FIRST TWO PROBLEMS.

JOHN T BURBA
GENERAL CONTRACTING - GREEN HARBOR, Massachusetts

INFORM THE COATING THICKNESS SPECIFIED FOR ANODIZING. WHETHER ELECTRO COLORED AND PROPERLY SEALED? IF COATING IS VERY SOFT WITH VERY LOW MICRONS,IMPROPERLY SEALED, THE STORM WATER WHICH HAS COME IN CONTACT, HAS REMOVED THE COATING, MAY BE DUE TO CHLORIDE OR OTHER CONTAMINENTS PRESENT IN WATER AND HAS ATTACKED BASIC ALUMINUM AND HAS ALSO ATTACKED ALUMINUM TO FORM WHITE POWDER MAY BE ALUMINUM CLORIDE.

H. K. BAPU RAMESH
- MYSORE, KARNATAKA, India