Rust-Oleum 633 Thinner is a clear, aliphatic hydrocarbon solvent formulated for thinning and clean-up of alkyd-based enamel coatings. It is specifically designed for use with Rust-Oleum primers including 769 Damp Proof Red Primer, 1060/1069 and X-60/960 Rust-Inhibitive Primers, and 678/7086 Quick Dry Primer. Its consistent formulation ensures optimal viscosity for application and enhances the performance of protective alkyd coatings.