HomeBLOGEducational ArticlesPaint Defects 6 – Fish Eyes

Paint Defects 6 – Fish Eyes

  • 20 July 2016
  • Posted by: Stm Coatech
  • Category: Educational Articles
574 Comments
boya-hatalari-6-balik-gozu-gorsel-1

Fish eyes are a type of coating defect which is characterized by circular voids or separation in the coating. Fish eyes are small, crater-like openings in the finish after it has been applied. They are usually caused by oil and grease on a coating substrate.

Fish eyes are also known as silicone contamination, poor wetting, saucering, pits, craters and cissing.
Fish eyes are a typical defect when paint is sprayed. They are small quasi-circular areas of substrate that are exposed through the applied coating immediately after application and which have at their center a source of contamination. Fish eyes can be caused by oily spots or silicone particles and/or by airborne droplets that are deposited on the painted surface.

When a coating is applied to a substrate that is contaminated with low surface energy particles such as oil, wax, grease or silicone, fish eyes may develop in the coating as it is applied. These fish eyes are produced because the coating is unable to wet out the contaminated area.

paint-defects-6-fish-eyes-image-1

Fish eye is a preparation defect. If the surface has been properly cleaned and degreased using a wax and grease remover, fish eye can usually be prevented completely. If fish eye does occur, particularly in the first coat, often painters will let that coat fully tack off, then follow it by a second coat, which often “bridges” the fish eye so that it becomes invisible. A third coat is applied, not only for full coverage but also to make sure that there is sufficient paint for detailing later. After the paint is fully cured, if slight remnants of the fish eye are visible, it can be sanded and polished.

boya-hatalari-6-balik-gozu-gorsel-3

If during the second coat the fish eyes are not bridged, it is highly unlikely that a third coat will accomplish an acceptable result. Therefore, in this instance the finish should be dried, sanded and repainted.

574 Comments

Comments are closed.