What Causes Fish Eyes in Gel Coat Applications?

Fish eyes are a coating defect characterized by small, circular pits on the surface after applying gel coat, resembling the appearance of fish eyes.

What causes this issue?

The presence of mold release agents, which are designed to prevent adhesion between surfaces, can interfere with the adhesion of paint or gel coat. If these agents are not properly removed through a thorough cleaning process, they can lead to fish eye defects. Utilizing alkaline cleaners can effectively eliminate mold release agents, typically done before spraying or plating operations.

Fish eyes can often be resolved by increasing surface tension. Selecting appropriate, high-quality mold release agents and using them correctly can help mitigate this defect.