• Substrate insufficiently dried
• Polyester material not isolated with 2K filler
• Pores not deeply sanded
• Allow preparation materials to dry thoroughly
• Deeply sand pores or re-apply filler/stopper
• Use a fine stopper to finish repair
• Mix hardener and stopper as completely as possible; avoid air bubbles
• Stopper application at a right angle prevents the formations of pores
• Fill pinholes with spray filler
• Sand damaged area and repaint