Alligatoring
In a coating film, a random pattern of cracks in one direction and somewhat
parallel cracks in the other direction giving an appearance resembling
the scaly hide on the back of an alligator or crocodile. These cracks
may extend to a previous coating, or may expose the original substrate.
(Also known as Crocodiling.)
Possible causes may be the application
of:
- a top coat before the undercoat is dry
- a top coat unable to bond to a glossy surface
- excessive coats of paint
- an excessively thick coat, preventing the under surface from drying
properly
- a hard, rigid coating (e.g. alkyd enamel) over a soft, flexible coating
(e.g. latex)
Another cause is loss of elasticity, normal in the later stages of
the natural aging process of oil/alkyd coatings rendering the film
unable to expand and contract with the undersurface during temperature
fluctuations.