We do not recommend using lacquer thinner for thinning RustSeal as it is incompatible and can cause issues with the RustSeal. However, lacquer thinner can be used for clean-up.
For thinning, we recommend using KBS #1 Thinner and if you do not have that, Xylene (Xylol) is also compatible and works well.
RustSeal Product Link 👉 https://www.kbs-coatings.com/rustseal.html
KBS #1 Thinner Product Link 👉 https://www.kbs-coatings.com/number-1-thinner.html
Please check out the complete RustSeal Application Directions before you begin your project.