Alligatoring is the phenomenon of fracturing that often occurs in the interaction between paint layers. It is also known as crazing.
Reasons for the Occurrence of Alligatoring
Some of the reasons alligatoring occurs can be the applications of coatings of paint over each other with no suitable primer in between. For instance, a very hard coating such as alkyd, or oil enamel, on top of a latex finish, such as a latex eggshell coat, can cause alligatoring. This occurs because the latex undercoat is more flexible in temperatures, while the enamel overcoat is rigid, and therefore will not bend or flex along with the latex coat.
Alligatoring can also occur when a top coat is applied to a surface when the undercoat isn’t completely dry.
Alligatoring can also happen when oil based paints age over a long period of time. This can happen to resin-based shellacs and clear finish polyurethanes as well.
Solutions to Alligatoring
Completely removing the old paint with a heat gun or paint stripper will prevent alligatoring.
Priming the surface with a high quality latex primer, then applying high quality latex finish paint will also prevent alligatoring problem
Faux paint products can produce artificial alligatoring in multi-step process, which recreates alligatoring, for a faux-antique look on furniture.