Bituminous Rustproofing (UB302B)

ENDRUST® UB302B Heavy Duty Underbody Rustproofing is a professional-grade, bituminous protective coating specifically designed for the underbody and exposed underside components of motor vehicles.

UB302B contains rust-converting and corrosion-inhibiting components, allowing it to be applied directly to properly prepared bare metal, sound existing coatings and light surface rust. Where only light surface oxidation or ferric oxide staining is present and the underlying surface remains sound, a separate rust converter or primer is generally not required.

Once applied, UB302B forms a durable, flexible and waterproof protective barrier that helps prevent further corrosion while providing excellent resistance to stone chips, sand, mud, water and other road debris. Its heavy-bodied coating also provides useful sound-deadening properties, helping to reduce road and underbody noise.

For surfaces affected by moderate to severe corrosion, any loose, scaling or flaking rust should first be removed by wire brushing, scraping or other suitable mechanical preparation. The remaining corrosion should then be treated with ENDRUST® RCP150 Rust Converter, Primer & Sealer before UB302B is applied.

UB302B is suitable for application to vehicle underbodies including chassis rails and cross-members, floor pans, wheel arches and other suitable exposed steel components. Its combination of corrosion protection, impact resistance and flexibility makes it particularly suited to 4WDs, passenger vehicles, commercial vehicles and vehicles regularly exposed to harsh road or off-road conditions.

Key Features:

• Contains rust-converting and corrosion-inhibiting components
• Suitable for application directly over properly prepared light surface rust
• Separate rust converter or primer generally not required for light surface corrosion
• Forms a durable, flexible and waterproof protective barrier
• Protects against corrosion, stone chips, sand, mud and road debris
• Helps reduce road and underbody noise
• Suitable for 4WD, passenger and commercial vehicles
• Compliant with AS 2662
• For moderate to severe corrosion, pre-treatment with ENDRUST® RCP150 is recommended

Q: Does Endrust UB302B contain a rust converter?
A: Yes. Endrust UB302B contains rust-converting and corrosion-inhibiting components. This means it can be applied directly over properly prepared light surface rust without requiring a separate rust converter or primer.

Where a vehicle has more significant existing rust, additional preparation and treatment with Endrust RCP150 Rust Converter, Primer & Sealer may be recommended before UB302B is applied.

Q: Can UB302B be applied to a vehicle that already has some rust?
A: Yes. Light surface rust is quite common, particularly on older vehicles, and UB302B is specifically suited to protecting these surfaces.

If more extensive rust is present, the condition is assessed first and additional preparation may be required before rustproofing. Rustproofing protects against further corrosion but is not a substitute for repairing metal that has already been seriously weakened by rust.

Q: Why choose a bituminous underbody rustproofing coating?
A: A quality bituminous coating such as UB302B provides a tough, flexible and water-resistant barrier between the vehicle underbody and the environment.

It is particularly well suited to areas exposed to water, mud, sand, salt, stones and road debris and remains flexible rather than forming a hard, brittle coating.

Q: Will UB302B protect against stone chips and road debris?
A: Yes. UB302B forms a durable, flexible coating that provides excellent protection against normal stone impact, abrasion and road debris.

Vehicles regularly driven on gravel roads, beaches or off-road can experience greater wear in high-impact areas, so occasional inspection and touch-up may be beneficial.

Q: Does UB302B help reduce road noise?
A: Yes. The heavy-bodied coating also provides sound-deadening properties, helping to reduce road noise and vibration transmitted through the vehicle floor and wheel arch areas.

Q: What parts of my vehicle can be protected with UB302B?
A: UB302B is designed primarily for the vehicle underbody and is commonly used to protect areas such as chassis rails, cross-members, floor pans, wheel arches and other exposed underbody steelwork.

A professional applicator will determine which areas should be coated and which components need to remain coating-free.

Q: Is UB302B suitable for 4WDs and vehicles used on beaches or off-road?
A: Yes. UB302B is particularly well suited to 4WDs, work vehicles and vehicles regularly exposed to coastal conditions, beaches, gravel roads, mud and off-road environments.

Its combination of corrosion protection, flexibility and resistance to stone impact makes it ideal for demanding underbody applications.

Q: How long does UB302B last?
A: When correctly applied to a properly prepared surface, UB302B provides long-term underbody corrosion protection.

The condition of any underbody coating will depend on how the vehicle is used. Vehicles subjected to frequent gravel, beach or off-road driving may experience localised wear or chipping over time, which can be easily inspected and touched up when required.

One I would now leave out

I’d actually remove the thixotropic FAQ completely from the customer page. Customers don’t need to understand rheology to decide whether UB302B is right for their vehicle. If “thixotropic” appears in the TDS, that’s the appropriate technical document for it.

These seven questions tell a much better customer story: yes, it contains rust converter → yes, it works with light existing rust → why bitumen → physical protection → noise reduction → where it goes → suitability/longevity.