Typical coatings that can be evaluated with this method are:
• Phosphated surfaces (with subsequent paint/primer/lacquer/rust preventive)
• Zinc and zinc-alloy plating (see also electroplating). See ISO 4042 for guidance
• Electroplated chromium, nickel, copper, tin
• Coatings not applied electrolytically, such as zinc flake coatings according to ISO 10683
• Organic coatings
Hot-dip galvanized surfaces are not generally tested in a salt spray test (see ISO 1461 or ISO 10684). Hot-dip galvanizing produces zinc carbonates when exposed to a natural environment, thus protecting the coating metal and reducing the corrosion rate.
The zinc carbonates are not produced when a hot-dip galvanized specimen is exposed to a salt spray fog, therefore this testing method does not give an accurate measurement of corrosion protection. ISO 9223 gives the guidelines for proper measurement of corrosion resistance for hot-dip galvanized specimens.
Painted surfaces with an underlying hot-dip galvanized coating can be tested according to this method. See ISO 12944-6.
Telephone: 01422 847671
in the UK
ISO 9001 - 2008 accredited