What causes solvent pop?

What causes solvent pop?

• A. Excessive heat during cure
• B. Trapped solvent from improper flash time
• C. Inadequate primer
• D. Too much pigment

Answer: (B)

Solvent pop happens when solvent vapors get trapped inside a wet film and can’t escape as the coating cures. If you don’t allow enough flash-off time between coats or you apply a subsequent coat too soon or too thick, the solvents stay in the film. As curing progresses, those trapped vapors try to escape and push the film, creating tiny bubbles or pimples on the surface. That’s why the correct choice points to trapped solvent from improper flash time.

To prevent this, always follow the product’s flash-off recommendations, spray lighter, even coats, and avoid layering coats before the previous layer has adequately flashed. Excess heat, inadequate primer, or too much pigment can cause other problems, but they’re not the primary cause of solvent pop.