Restoring the Foundation: Repairing the Rusted Floor Pan on the PUG Truck
When building a purpose-driven disaster response vehicle, every detail matters—especially the foundation. During the early stages of our PUG Truck build, we uncovered an issue that required immediate attention: extensive rust damage in the driver-side floor pan of the cab. What initially looked like minor corrosion turned out to be a long-term water intrusion problem that had quietly compromised the integrity of the cab floor.
Discovering the Problem
When we first acquired the truck, we weren’t fully aware of how severe the rust issue was. Over time, improperly secured A-pillar weather stripping allowed water to enter the cab. Unfortunately, the factory sound-deadening material absorbed and trapped that moisture for years. The result was a rusted-through floorboard that needed more than a quick patch—it required a proper structural repair.
Because this truck will serve in extreme environments and long deployments after hurricanes and tornadoes, simply covering the damage wasn’t an option. Our goal was to fix the issue the right way and improve upon the factory design where possible.
Step-by-Step Floor Pan Repair Process
1. Cleaning and Assessing the Damage
We began by removing loose rust and thoroughly cleaning the floor pan. This allowed us to clearly see the extent of the corrosion and identify all affected areas.
2. Removing the Rusted Sections
Using a right-angle die grinder and chisel, we carefully cut away the rusted portions of the floor pan and cab corner, ensuring all compromised metal was fully removed.
3. Measuring and Templating
Replacement sections were carefully measured and templated to match the contours of the original floor pan while improving structural integrity where possible.
4. CAD Design and Fitment Verification
The templates were transferred into CAD files, allowing us to reverify fitment and refine the design before cutting metal.
5. CNC Plasma Cutting
The finalized templates were CNC plasma cut from 18-gauge steel, ensuring precise, repeatable, and clean cuts for a professional-quality repair.
6. Forming and Tacking
Each panel was formed to match the cab contours. We welded the underside reinforcement pieces first, followed by tacking of the outer floor sections to ensure proper alignment and strength.
7. Full Welding for Strength and Sealing
All replacement panels were fully welded on both the inside and outside of the cab. This not only restores structural integrity but also ensures a completely waterproof repair—critical for a disaster response vehicle.
8. Rust Prevention Coating
Both sides of the repair were coated with a rust-resistant product such as POR-15 to protect the metal and prevent future corrosion.
9. Seam Sealing
All seams were sealed inside and out using 3M two-part epoxy body panel seam sealer, creating a durable, moisture-proof barrier.
10. Upgraded Sound Deadening
Finally, the old moisture-absorbing sound deadening was replaced with marine-grade, waterproof material like Kilmat, eliminating the risk of trapped water in the future.
A Stronger-Than-Factory Result
This process was time-consuming and detail-oriented, but the result is a stronger-than-factory floor pan that improves both rigidity and long-term durability. By designing our repair templates to add structure and reinforcement, we not only fixed the problem—we improved the cab for the demanding role it will play in disaster response.
The PUG Truck is being built to operate in the harshest conditions, and that starts with a solid foundation. This repair ensures the cab is ready for years of service as we continue building the ultimate grapple saw truck to help families recover after storms.
Stay tuned for more updates as the PUG Truck build continues.