What defect occurs when lacquer is sprayed on polished silicone surfaces?

What defect occurs when lacquer is sprayed on polished silicone surfaces?

• A. Fisheye
• B. Blistering
• C. Sagging
• D. Orange peel

Answer: (A)

When lacquer is sprayed onto polished silicone, the surface is contaminated with silicone, which repels the coating and prevents proper wetting. This causes the film to pull away around the contaminant, leaving round, crater-like defects known as fish-eyes. The coating beads at the contaminant and the area around it remains clear of film, giving that characteristic circular void. This is different from orange peel, which is a bumpy, textured surface from improper atomization or viscosity; blistering, which involves bubbles forming under the coating; and sagging, which is a downward flow or droop of the film during curing. The silicone surface specifically creates fish-eyes due to poor wetting by the finish.

When lacquer is sprayed onto polished silicone, the surface is contaminated with silicone, which repels the coating and prevents proper wetting. This causes the film to pull away around the contaminant, leaving round, crater-like defects known as fish-eyes. The coating beads at the contaminant and the area around it remains clear of film, giving that characteristic circular void.

This is different from orange peel, which is a bumpy, textured surface from improper atomization or viscosity; blistering, which involves bubbles forming under the coating; and sagging, which is a downward flow or droop of the film during curing. The silicone surface specifically creates fish-eyes due to poor wetting by the finish.