World's #1 on-line resource since 1989-----
Etch on extruded aluminum
I have a five stage wash line, alkaline cleaner, rinse, iron phosphate, rinse, rinse. I am trying to etch extruded aluminum to be painted, the problem is we cannot use fluoride. Is there an alternative to this without etching in the alkaline tank. There is not enough control on the etch in the alkaline tank.
- Ozark, Missouri, U.S.A.
I am a bit confused . . . you're not attempting to run your aluminum though your iron phosphate line, are you? It won't work well. You really need a separate tank line with a non-etch cleaner, aluminum etch, and de-smut tanks. And chromating would be much better.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Every cleaner salesman calling on you has a product in his line consisting of detergent and phosphoric acid in varying degrees with different product names. This type of product has been used on window and door extrusions for over 50 years, mostly by immersion but the product will work when sprayed. You might have some difficulty getting the particular blend that fits enough detergent for cleaning and enough phosphoric for etching. Try it you'll like it. Put this product in the first stage, be careful, too much phosphoric will eat up the mild steel (But not near as fast as ammonium bifluoride)
Robert H Probert Technical Services
Garner, North Carolina
Have you considered using acid etch?Dado Macapagal