Welcome back to the StealthBuilt Audi A6 Widebody Build! In Part 4 of this extreme custom series, Sam Kimmel walks us through the critical next phase — building out the side skirts and laying down the first layers of fiberglass for the front and rear fender flares. If you’re planning a custom body kit or want to understand the fabrication process behind widebody panels, this episode is packed with real-world techniques and shop tips.
Building the Side Skirts with Hardboard Precision
The episode starts by revisiting the side skirt base introduced in the previous video. Sam uses:
- ¼” hardboard (particle board) for structural inserts
- A table saw for clean, uniform cuts
- Cordless metal shears to shape angles for a flush fit
Once cut, the boards are glued into place with hot glue, then reinforced and taped, creating a sturdy base for fiberglass work. By pre-cutting both sides at once, Sam saves time and ensures symmetry across the car.
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A Smarter Way to Seal with Aluminum Foil
Instead of relying on expensive aluminum tape, Sam uses 3M Super 77 spray adhesive to apply standard aluminum foil to the flare frames. This creates a dual benefit:
- It prevents fiberglass resin from leaking onto paint, tires, or the garage floor.
- It allows the fiberglass part to release cleanly after curing.
This step highlights a low-cost, high-efficiency method ideal for builders working with resin-based composites.
Adjusting the Splitter & Prepping for Glass Work
Sam constructs each flare with two layers of dowel rods: The front splitter, previously oversized for flexibility, is trimmed to match the new flare dimensions. Sam uses an air saw for smooth cuts and follows up with a router to round over edges. He even reuses the same router profile on the side skirts for design consistency.
To keep the mock-up wheels clean, garbage bags serve as quick-and-easy protection while sanding and trimming are underway.
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Setting Up the Workspace for Fiberglass
Before mixing resin, Sam emphasizes the importance of:
- Setting up all tools and materials within arm’s reach
- Tearing fiberglass into manageable pieces
- Observing all safety guidelines (gloves, glasses, proper ventilation)
Fiberglass resin has a limited pot life, so prepping ahead is essential to avoid wasted material and rushed applications.
The Fiberglass Layup Process Begins
With everything in place, Sam wets out fiberglass strips on a work table and transfers them to the car. He works methodically:
- Starting at the front flares
- Moving along the side skirt area
- Wrapping around the rear fenders and door blades
This step is more than just structure—it’s about creating removable mold-ready bases for the final kit. Sam explains:
“This is just a base for us to get a mold. We’ll use that mold to make new parts, and if any part gets damaged, we can reproduce it.”
Door Flare Integration and Why It’s Built On the Door
One standout detail is how Sam builds flare extensions onto the doors themselves rather than trimming into the door to fit around a flare. Why?
- It avoids cutting into door seals, jam areas, and internal mechanisms
- It allows for better design control
- It makes mold creation cleaner and more reusable
He wraps tape over the dowel-built forms, checks door clearance, and shapes the curves with precision — even under the door and into the rocker transition.
Final Thoughts and What’s Coming Next
With fiberglass laid down and the core structure formed, this video wraps up the foundational phase of the widebody. Next up? Bodywork, mold making, and refinement.
Sam also shares that the final kit is over 8 inches wider per side, making this a truly extreme build—not a bolt-on solution you’d find online.
Want to See More?
📺 Watch the full Part 4 video here on YouTube
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