Summary for white rust removal from aluminum Discussion
White rust removal from aluminum is discussed in the context of condenser fan blades that show white patches on the blade surface and inside the mounting bush, with the parts needing to keep their finish, balance, and performance in hot, humid outdoor service. Sethu Raman asked for an effective way to remove the corrosion and restore the parts for use. Mark suggested trying an aluminum restorer and polish, and Sethu said he would test the suggested method and ask again if needed. James Watts then offered a different view: the spots looked more like fingerprints or palm marks from handling without gloves during assembly than true corrosion, and he advised complaining to the vendor who supplied the blades. The thread therefore presents both a cleaning/restoration suggestion and a possible quality-control issue, with the cause of the marks not definitively established in the excerpt.
Q. We have Aluminum blades used for the condenser fans of Air Conditioners which are having patches of white rust on the blades surface and inside the mounting bush. We need an effective method to remove the rust and restore its finish for usage. These blades are supposed to perform at High Ambient and Humid conditions exposed to the sky at approx. 1000 to 1200 RPM and are also dynamically balanced.
Sethu Raman
– Bahrain
October 29, 2014
A. Hello,
Aluminum naturally forms an oxide which appears white in color. This is especially true in atmospheric conditions. Aluminum in its pure form can’t rust. Why it appears only in spots could be the exposure to moisture in just a few areas. I find that a non abrasive Aluminum Polish works well, or if you don’t have many fan blades to do, cream of tartar also works well. I add distilled water to the cream of tartar to make a paste. Dip a soft microfiber rag in the paste and rub the oxidation off. Wipe clean with a rag dipped in distilled water and dry. Sorry the answer is so lengthy. Sometimes when people ask me the time of day I want to build them a watch!!
Mark Baker
Process Engineer – Phoenix, Arizona USA
October 31, 2014
Thank you Mark for the prompt response. Let us try out the suggested method and seek your further advice if any.
Sethu Raman
– Sitra, Manama, Bahrain
October 30, 2014
A. The spots/areas look very much like palm and finger prints from being handled without gloves, probably during assembly.
I would gripe to the vendor that you bought them from.
James Watts
– Navarre, Florida