Flash Rust

Posted on 03. Mar, 2009 by in Flash Rust

Dust is to paint as grease is to tires.

Every thing you wanted to know about flash rust and whether to paint over it.

2 Responses to “Flash Rust”

  1. Jack

    08. Nov, 2010

    Hello,
    I am looking for a way to test flash rust inhibitors in a humidity chamber. I have yet to find a standard that covers this topic. I’ve read many of the ASTM humidity tests and most are for painted surfaces. I am trying to determine what temperature and RH to run a test for 24 hours. Does anyone know of such a standard test?

  2. lydia frenzel

    25. Apr, 2011

    Hi Jack- You understand that “FLASH RUST” is the oxidation (rust) during surface preparation that occurs as the carbon steel is drying.

    The classic test for inhibitor is to place the steel surface into immersion of water with the recommended level of inhibitor. Iit is a comparison test. YOu can put it at the temperature that you expect to experience in your field conditions.

    SSPC has a standard method for producing uncontaminated rusted steel panels. This method , Test Panel Preparation, Method NO. 1, Uncontaminated Rusted Steel, can be used for your comparison, It was used to prepare Grade C rust on panels so that paints could be put on and the performance could be evaluated.
    In summary- they clean with solvent, dry blast to near white, and place in an ASTM G 85, Annex A.5 cyclic chamber, 1 hour wet and 1 hour dry.

    I would think that you would get comparison results in 24 hours.
    The total time is up to you. YOu should be comparing a known panel without any inhibitor to panels with the inhibitor.

Leave a Reply