Rustbuster Epoxy Thinner

Extra thinner for Rustbuster’s two-pack epoxy paints: Armaguard Epoxy Mastic rust-proofing paint and Custom 421 Epoxy Primer.

Both are supplied as two-component kits complete with thinner, and both mix at 3:1 by volume (3 parts component A to 1 part component B). They’re thick, high-solids paints, so correct thinning matters for a smooth, even finish whether you brush or spray. Buy extra thinner here if you’re spraying, tackling a larger job or working in cold conditions where the paint is thicker.

How to use

• Mix components A and B thoroughly first, then add thinner.
• Thin by 5–20% maximum.
• Never thin these epoxies with standard thinner, as it will affect the cure.

For full step-by-step instructions, see our guides: How to Use Rustbuster Epoxy Mastic and How to Use Custom 421 Epoxy Primer.