Pettit 120 Brushing Thinner is a general purpose thinner. Many paints when stored for some time before use will increase in viscosity and should be thinned. 120 Brushing Thinner evaporates at a moderate rate and is completely out of the paint film in several hours. Up to 10% is the normal recommended usage, some very hot and windy days may require more thinner. 120 Brushing Thinner is the recommended thinner for clean-up of all Pettit, Z*Spar and Shipendec solvent based topside enamels and varnishes as well as all antifouling paints except for Hydrocoat and Ultima SR-60. Pettit Part number 12120.