The recommended rate of catalyzation is 14 drops of MEKP per ounce of TotalBoat Polyester Structural Marine Repair Putty. There are 6 teaspoons per ounce, so the recommendation is 2-3 drops of MEKP per teaspoon. By volume in milliliters, the MEKP and putty are both very close in density, so you can add 1 ml of MEKP per 100 ml of putty at 77°F for 10-15 minutes of working time.