2L 1K Black Rubberized Stone Chip Coating for Automotive Underbody Wheel Arch

Product Overview

Hummingbird 2L 1K Black Stone Chip Coating is a single-component, spray-gun-applied coating for restoring a textured protective layer on suitable automotive lower-body areas. It is intended primarily for wheel arches, inner fenders, rocker panels, side skirts and localized underbody repairs after the substrate has been correctly repaired and prepared.

The coating is supplied ready for use as a 1K system, so no separate hardener is required. A compatible pneumatic stone-chip or underbody coating gun is used to build a black textured finish. Texture is influenced by the gun, material flow, air pressure, spray distance and operator technique; always confirm the appearance on a test panel first.

Recommended Repair Areas

• Wheel arches and inner fenders
• Rocker panels and side skirts
• Lower body sections exposed to road debris
• Localized underbody areas after collision or corrosion repair
• Repaired steel panels and weld areas after suitable priming and sealing

Do not use this product as cavity wax. Enclosed body cavities require a material designed specifically for internal cavity protection.

Product Characteristics

Professional Application Guide

1. Inspect the Repair Area

Complete all required panel straightening, welding and structural work before coating. Confirm that drains, service points, threaded interfaces, moving parts and heat-producing components can remain unobstructed.

2. Remove Contamination and Corrosion

Remove mud, oil, grease, wax, road film, loose coating and active rust. Heavily corroded metal must be repaired and treated with the appropriate corrosion-protection system before stone-chip coating is applied.

3. Prepare the Substrate

Abrade sound compatible coatings or primers as required by the selected repair system. The surface must be clean, completely dry and free from sanding dust. Bare metal should receive the appropriate compatible primer when required.

4. Mask Carefully

Protect exterior paint, glass, lamps, wheels, tires, exhaust parts, brakes, brake lines, wiring, sensors, hoses, drain holes, fasteners and service access points. Dried textured coating can be difficult to remove from unintended areas.

5. Prepare the Material

Mix the coating thoroughly until it is uniform. No hardener is required. Do not add general-purpose thinner without written compatibility guidance for this product; changing viscosity can affect atomization, texture, sag resistance, drying and film build.

6. Set Up and Test the Gun

Use a compatible pneumatic stone-chip gun. Begin with the gun manufacturer's recommended setup and the current product TDS, then test on a sample panel. Adjust only one parameter at a time until the required texture is achieved.

7. Apply Controlled Coats

Apply a light, even first coat rather than attempting full texture in one heavy pass. Allow the specified flash-off, then build coverage and texture with additional controlled coats if required. Excessive wet-film thickness can lead to sagging, texture collapse and extended drying.

8. Dry and Inspect

Allow the coating to dry under suitable temperature and ventilation. Drying varies with film thickness, airflow, humidity, substrate temperature and number of coats. Do not judge full cure only by surface touch. Inspect coverage, drainage openings and adjacent components before returning the vehicle to service.

9. Clean Equipment

Clean the gun and material passages immediately after application using the cleaning method specified for the coating and equipment.

How to Control the Texture

Application Boundaries

Do Not Coat

• Exhaust pipes, mufflers, catalytic converters or other high-temperature parts
• Brake discs, friction surfaces, calipers or critical brake interfaces
• Moving joints, drive shafts or suspension movement points
• Drain holes, threaded service points or mechanical connections
• Structural bonding areas
• Active rust, wet surfaces or oil- and wax-contaminated substrates

Test Before Wider Use

Plastics, galvanized steel, stainless steel, aluminum, unknown old coatings and non-standard primers require an adhesion and compatibility test with the complete repair system.

Workshop Troubleshooting

Texture is inconsistent

Check material mixing, gun cleanliness, spray distance, air supply, gun speed and overlap. Standardize the test-panel setup before changing multiple variables.

Coating sags or the pattern collapses

Film build may be too heavy, flash-off may be insufficient, or material flow may be excessive. Allow the correct interval and use controlled coats.

Adhesion is poor

Check for residual wax, grease, moisture, rust, loose coating, inadequate abrasion or an incompatible substrate/primer combination.

Drying is slower than expected

Review film thickness, ventilation, temperature, humidity and any unauthorized thinner addition. Compare the conditions with the current TDS.

Safety, Storage and Technical Evidence

Use appropriate respiratory protection, gloves, eye protection and ventilation. Follow the current SDS for handling, storage, fire precautions and disposal. Keep the container sealed in a cool, dry and ventilated location away from ignition sources.

For a technically credible product page, publish the current TDS/SDS revision, verified drying conditions, compatible primers, coverage data and real test-panel photographs when these records are available.

Application FAQ

Does the coating need a hardener?

No. It is a 1K coating and does not use a separate curing agent.

Can it be sprayed directly over rust?

No. Active corrosion must be removed and the substrate treated with the appropriate repair and corrosion-protection system first.

Can the texture be adjusted?

Yes. Gun setup, material flow, pressure, distance and technique influence the result. Use a test panel rather than promising an exact OEM texture.

Can it be used inside body cavities?

It should not replace a dedicated cavity wax or cavity-protection product.

Can it be applied to exhaust or brake parts?

No. Heat-producing, friction, braking and moving components must remain uncoated.