Over the past year, the cost of key ingredients for our EM121 Epoxy Mastic has soared—some by as much as 200%. Rather than compromise on quality, we sought a solution that maintains the high performance you expect from Rustbuster.

After extensive testing, we launched Armaguard Epoxy Mastic last year, running it alongside EM121. With hundreds of litres sold and zero complaints, it has proven to be the tough, surface-tolerant, high-build epoxy you need.

As we move into 2025, Armaguard will officially replace EM121 in the coming weeks. Expect the same durability, flexibility, and colour range—just under a new name.

New for 2025 – Rustbuster’s Armaguard Epoxy Mastic

Rustbuster Armaguard Epoxy Mastic is a high-build, high-solids, two-pack epoxy coating (base and hardener) designed to renovate and protect rusting and pitted steel in the most severe environments.

It adheres exceptionally well to wire brush-cleaned steel, delivering the same outstanding performance as coatings applied over blast-cleaned surfaces. The finish is as hard as iron, yet remains flexible, moving with the steel to prevent cracking.

Key Benefits:

✅ Tough & flexible – requires minimal surface preparation
✅ Cold cure – effective at temperatures as low as -10°C
✅ Higher solids – more material stays on the surface
✅ Faster overcoating – reduced waiting times between coats
✅ 3:1 mix ratio – more paint, less hardener

How Does It Work?

Rustbuster Armaguard Epoxy Mastic is formulated with nanoscale corrosion-protective pigments and short-chain molecules with low surface tension.

This unique composition allows the coating to flow into pits and troughs on the steel’s surface, creating a tough, penetrating primary bond for long-lasting protection.

This forms one of the best bonds achievable with a paint finish. The high-build epoxy creates a strong protective barrier over the corrosion-inhibiting pigments, which tightly adhere to the steel’s surface.

With exceptional penetration and adhesion, this coating provides superior mechanical strength while forming a non-porous barrier that protects against moisture, salt, and environmental contaminants.

Why Can’t Other Paints Do This?

Most rust-protection paints are single-pack coatings (without a hardener). These paints use standard-sized pigments bound in long-chain molecules, which have higher surface tension.

As a result:

• They tend to sit on top of the steel’s pits and troughs rather than flowing into them.
• The larger pigments struggle to form a tight, protective matrix, leaving gaps where rust can take hold.

With Armaguard Epoxy Mastic, you get superior protection, longer-lasting durability, and enhanced performance, ensuring your metalwork remains rust-free for years to come.