Alligatoring is the patterned cracking in the surface of the paint film resembling the
regular scales of an alligator.

Possible cause

  • The application of an extremely hard, rigid coating (like a solvent-based enamel) over a more flexible coating, like a water-based primer
  • Applying your topcoat before the undercoat is dry
  • The natural aging of oil-based paints as outdoor temperatures fluctuate. The constant expansion and contraction of the paint based on the temperature can result in a loss of paint film elasticity

 

Solution

Old paint should be completely removed by scraping and sanding the
surface; a heat gun can be used to speed work on large surfaces, but take care to avoid igniting paint or substrate.

The surface should be primed with a high quality water-based primer and then painted with a top quality exterior water-based paint. Dulux recommends Dulux Weathershield® for a premium exterior paint.


More problem solving advice

Yellowing

Development of a yellow cast in aging paint solvent-based enamels

Wrinkling

A rough, crinkled paint surface occurring when paint forms a 'skin'.

Tannin staining

Brownish or tan discoloration on the paint surface due to migration of tannins from the substrate through the paint film.