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  for Metal Finishing since 1989
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WHITE RUST

 

I wonder if you could give some advise for my problem. We have certain materials (Aluminum and Aluminum-Zinc Coated Steel) on which "White Rust" has developed. IS THERE ANYWAY OF TREATING THE SHEET TO REMOVE THE RUST? IF YES, IS THIS PRODUCT AVAILABLE IN SINGAPORE OR ASIA ?

Thank you for your assistance.

Looking forward to your speedy response.

Mike Sehgal
- Singapore

There are two options to remove the rust from the sheets. First option is to remove the rust with a mechanical pretreatment. During this mechanical pretreament sand is blowed on the metal sheet with high pressure. Second option is to remove the rust with a chemical pretreament. During this chemical pretreatment the metal sheet will be immersed in a hydrochloric solution. The time of this immersion is depend of how rust is present.

Hendrik Wegter
- Amsterdam, Holland

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Hydrochloric acid will strip all the zinc in the process. If you do not want to remove the zinc try a phosphoric acid based etch, which will convert some of the zinc to a phosphate coating, which will clean the white rust and prepare the surface for painting or whatever you are trying to do afterwards. I am afraid I do not know where you can buy the product but check for phosphating and metal treatment suppliers.

Good Luck,

Trudy Kastner
electroplating service - Durban, KZN, South Africa