Peugeot Boxer Horsebox Structural Rust Remediation

1. Executive Summary

The vehicle was presented to CPRS with visible bubbling along the door sills and wheel arches. Upon initial teardown, the damage was found to be far more extensive than a “surface fix” could address. The project required deep surgical metal replacement to ensure the structural integrity of the cab and the safety of both the driver and the livestock.

2. Condition Assessment & Challenges

Horseboxes are particularly susceptible to corrosion due to exposure to mud, damp straw, and road salt, which trap moisture against the lower steel panels.

• The Sills: The main outer sill had completely rotted through, creating a large cavity. This compromised the jacking points and the side impact strength of the cab.
• Inner Steps & Floor: Moisture had migrated inward, attacking the seat box area and the internal step well where the wiring looms are housed.
• Wheel Arches: The inner and outer wheel arch lips had succumbed to “road spray” erosion, leaving jagged, weakened edges.

3. The CPRS Restoration Process

CPRS followed a professional “cut and weld” methodology rather than using temporary fillers.

Deconstruction & Cleaning

To reach the rot, the team removed the doors, interior trim, and seat boxes. This exposed the wiring harness to ensure no electrical damage occurred during the hot work (welding).

Surgical Metal Removal

CPRS technicians used plasma cutters and grinders to remove all “diseased” metal. A key rule in their process is cutting back to clean, bright steel to ensure a high-quality weld pool.

Fabrication & Welding

Since horseboxes often have custom skirts, off-the-shelf panels don’t always fit perfectly. CPRS:

• Fabricated custom steel patches for the inner floor and step wells.
• Welded in new outer sill sections.
• Reconstructed the wheel arch lips to restore the original factory contour.

Corrosion Prevention & Paint

To ensure the rust doesn’t return, the new metal was treated with:

1. Zinc-rich primers for galvanic protection.
2. Seam sealer to prevent water ingress between overlapping panels.
3. Refinishing: The vehicle was colour-matched to its distinct metallic electric blue. The blend is seamless, masking any evidence of the major surgery performed.

4. Results

The vehicle was returned to the owner with its structural integrity fully restored. By addressing the rot in the step wells and sills, CPRS extended the service life of the horsebox by several years and ensured it would pass stringent MOT/plating inspections.

Don’t let hidden rust put your vehicle — or your safety — at risk.

If your horsebox is showing signs of bubbling paint or soft sills, it’s often what’s underneath that matters most. At CPRS, we specialise in professional structural welding and high-end refinishing to get your vehicle back to factory standards.