Blisters

Cause

• Lack of insulation of polyester materials
• Water condensation when temperature change
• Polluted installation of compressed air
• Hygroscopy of the substrate (wet on wet sanding)

Countermeasure

• Dry sanding
• Use correct filters for compressed air
• Seclude polyester materials
• Avoid damp spaces

Removal

• Dry sanding
• Use correct filters for compressed air
• Isolate polyester materials
• Avoid damp spaces