POR-15 Solvent is the only appropriate clean up solvent or coating thinner when painting with a spray gun for most POR-15 coatings. We developed this POR-15 reducer precisely for these purposes, at the request of many of our loyal customers. This reducer paint works great when thinning POR-15 2k Urethane, POR-15 High Temp, and POR-15 Rust Preventive Coating. Depending on VOC laws in your area, you can thin between 5%-20% when applying with a spray gun or brush. *This paint cleaning solvent is not for sale in the state of California. Compatible with POR-15 Rust Preventive Coating 2K Urethane Industrial Coating High Temp