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What to replace chromium trioxide with in rust converter
(-----) February 2, 2018
Q. I have a rust converter formulation that contains phosphoric, nitric, Teric LA8, butyl icinol and chromium trioxide.
I would like to replace the chromium trioxide with a less dangerous chemical.
What would you suggest?
manufacturer - Queensland Australia
A. Hi. I certainly agree that you should try to get hexavalent chromium out of that formulation. How about simply leaving it out?
Do you know what roles it plays? It is an oxidizing agent, of course, but you already have another oxidizer, nitric acid, in the formulation. Do you feel that the chromium provides corrosion resistance, or perhaps helps protect any galvanizing remaining on the treated surfaces?
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey