finishing.com logo
    HOME / sitemapFAQsBOOKSHelp WantedsAdvertiseContact   you are here: Hotline/Forum => Letter 37395
most fun in metal finishing

BLACK STAIN (HYDRATED ALUMINUM OXIDE) REMOVAL

adv. pointer 

     
+++++

I buy and sell secondary coated steels (galvanized, aluminized, etc). I bought about 30 tons of steel coils that exhibit a black, pronounced stain that I need to remove.
The black stain apperars along most of the surface of the steel. The steel is comercially called Galvalume (an Aluminum/Zinc coating is applied continuosly to the steel. The black stain is likely the result of long term oxidation (steel got wet).
Are there products commercially available that may remove the stain?
Is mechanical removal of the stain possible?
Are there proven methods to remove such a "hard" dark stain?- even if removal is only partial.
Are there companies that provide such stain removal service?
Regards,

Jose Campos
steel - Rancho Viejo, Texas


+++++

If the stain is aluminum oxide, sodium hydroxide should be able to remove it easily without (I believe - test it youself first) hurting the steel to any significant degree.

If you don't have NaOH handy, but you want to test the idea before sending it to someone who does, try some oven cleaner.

Jim Gorsich
Accurate Anodizing Inc.

Compton, California, USA



ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

disclaim

 seek

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & DevicesUsed & Surplus


©1995-2014 finishing.com     -    Privacy    -    Search