Potassium Ferricyanide Test

The Potassium Ferricyanide Test will enable detection of any water-soluble iron salts that form at the bottom of rust pits afte blast-cleaning. If these salts are present, they rapidly induce corrosion.

The test involves the reaction of soluble ferrous iron salts with potassium ferricyanide to form ferric hexacyano ferrate, which is commonly known as Prussian Blue. The relatively high tinting strength of Prussian Blue enables the reaction to be used as a very sensitive test on ferrous irons. Simply spray a film of deionised water on an area of the blast-cleaned steel. The test paper is then held against the surface for about 10 seconds. Any soluble iron salts present are drawn out of the rust pits by capillary action and react with the potassium ferricyanide to form blue spots. The presence of blue spots on the test paper indicates that the surface should be re-blasted. Supplied with 100 Potassium Ferricyanide Test Papers, Deionised Water Spray Bottle, Plastic Gloves and Carrying Case.