Combined tannate/decanoate coatings

This study focused on tannate and decanoate coatings on iron surfaces and their potential combinations. The properties of the coatings were evaluated using a broad range of methods: spectrophotometry, contact angles measurement, impedance spectroscopy, mass gain, glow discharge optical emission spectroscopy (GD-OES), resistometry, and exposure experiments complete with digital image analysis. A decanoate coating was superior in a humid environment (low wettability and water vapour permeability) than tannate. A combined coating, with tannate deposited initially and then sealed in a decanoate bath, appeared to provide an ideal coating.