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Skipping Phosphatizing Process for Aluminum Painting
Hi there
I would like to know, what if I skip the phosphatizing process to aluminum frames from my paint line.
I paint both steel and aluminum frames but I'm not sure if phosphatizing just applies to steel and not to aluminum?
Thanks and best regards.
Plating Shop Quality Engineer - Quer´taro, Mexico
March 26, 2008
Aluminum, like other metals, must be pre-treated before painting, Miquel. The best pretreatment is chromate conversion coating. Next best is phosphatizing in a phosphating bath which is designed to handle aluminum as well as steel. Not pretreating is not a good option. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
March 27, 2008
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Fluorides added to the phosphate etch the aluminum in a multi-metal phosphate bath, so you are right in that the phosphates aren't the pretreatment for aluminum. It would probably be a good idea to talk to your chemical vendor and find out exactly what he is selling you.  Sheldon Taylor supply chain electronics Wake Forest, North Carolina March 30, 2008 According to some expired patents(try uspto.gov website) tannin based solutions(1 gm tannin/0,003 gm titanium potassium fluoride/1 lit water) can be used as pretreatment too.Maybe not so effective as hex chromates or phosphates but much more environment friendly option.Hope it helps and good luck! Goran Budija- Cerovski vrh Croatia March 31, 2008 |
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