Electrochemical corrosion testing of fasteners in extracts of treated wood

A recent change in wood preservatives has highlighted the need for a rapid, quantitative test to measure the corrosion rates of metals in contact with treated wood that could be used to evaluate new fasteners or new wood preservatives. A new method was developed where polarisation resistance tests were conducted on fasteners exposed to a water extract of wood treated with alkaline copper quaternary (ACQ). Good correlation was found between the corrosion rates using this new method and previous one year exposure data for carbon steel, hot-dip galvanized and electroplated galvanized fasteners. These data suggest that polarisation tests run in wood extract may be an effective, rapid test method to evaluate new fasteners or wood preservatives.