SPOT PUTTY is ready for use. Apply in thin coats as required. Where heavier builds are required use 2-3 applications, allowing 10 to 15 minutes drying time between coats. Problems may occur later if used for deep filling. Shrinking or cracking could occur if application is too heavy. Before final sanding allow a drying time of 30 minutes and up to 4 hours for heavier builds depending on the temperature. Sand with 320-400 Wet or Dry paper. Seal with MOTOSPRAY ACRYLIC PRIMER SURFACER prior to applying topcoats.