Can I use Mastercoat Permanent Rust Sealer under bedliner?

Yes. Apply two coats of Mastercoat Permanent Rust Sealer and then apply the bedliner as soon as Mastercoat Permanent Rust Sealer is dry to the touch to ensure maximum adhesion. Check out our Sound Deadener and Thermal Insulator--adding this to our AG111 makes a great bedliner!  It can be added to Mastercoat Permanent Rust Sealer, or any paint.