Martin Senour TP520 primer surfacer offers exceptional speed. Applies in 2 minutes and is dries in just 10-15 minutes. Mix Ratio: 2 parts primer : 2 parts reducer : 1 part activator. Application: Apply 2-3 wet coats with no flash time between coats. Wait 10-15 min. and wetsand with 600 grit sandpaper.