SR28 Performance of New Zealand wood primers (2007)

Recent developments in wood priming practice in New Zealand have been moves away from lead pigments in primers and oil-based paint systems. New practices include the use of acrylic and oil-alkyd resins for wood primers and overcoat systems. Finger-jointed weatherboards and priming by machine at the mill are also relatively recent developments.

This report describes a testing programme using a range of New Zealand primers, both acrylic waterborne and oil-alkyd solventborne, which was designed to investigate the effect of these new practices on the performance of paint systems on timber.

The main areas looked at were:

• length of primer exposure before overcoating
• effect of finger-joints in timber
• type of topcoat
• machine application of primer
• preservative type.