RV Fiberglass Repair in Brea, CA

What this repair covers

Anything where the glass reinforcement or the gelcoat film has failed belongs here. That includes cracks, punctures, fractured fibers, gouges through the gelcoat into the laminate, previous repairs that shrank or cracked, and gelcoat surface failures like crazing and print-through. It also includes rebuilding a section of laminate where thickness was lost, and molded cap replacement when the geometry is too complex to rebuild by hand.

What matters at intake is depth. Gelcoat is typically fifteen to twenty five thousandths of an inch thick. Damage that stops inside it is a finish repair. Damage that reaches the reinforcement below it is a structural laminate repair, and the two have almost nothing in common procedurally.

In scope on this page:

• Star, spider, and stress cracks in gelcoat and the laminate below
• Punctures and gouges through the skin, including core crush behind them
• Scarf ground laminate repairs with a rebuilt reinforcement schedule
• Gelcoat repair, color matching, spray application, and cut and polish to the surrounding surface
• Failed prior repairs where polyester filler was used in place of laminate
• Full front cap and rear cap removal and replacement
• Fiberglass compartment doors, fender skirts, and molded trim components

Damage and failure modes we see

Composite failures almost always start at a stress concentration. Find the concentration and you find the cause, and a repair that does not address the concentration cracks again in the same place.

How we perform this repair

Laminate repair is a chemistry job as much as a body job. Resin ratio, ambient temperature, and cure time are not suggestions, and a laminate that gels before it is properly consolidated is weaker than the material it replaced.

The sequence, start to finish:

1. Sound the panel and mark the boundary. Tapping with a phenolic hammer finds the full extent of debonded and fractured laminate, which is always larger than the visible damage. The repair boundary is chalked to sound material.
2. Grind a scarf taper. The damaged laminate is ground out to a taper of roughly twelve to one, so a quarter inch thick laminate gets a three inch wide taper on every side. That taper is the bond area, and it is what carries load across the repair.
3. Rebuild the core if it moved. Crushed foam is cut out and replaced with matched density block foam bedded in thickened epoxy. Damaged luan substrate is replaced in kind before any skin work begins.
4. Lay up the reinforcement schedule. We alternate one and a half ounce chopped strand mat with 1708 biaxial fabric, largest ply first against the taper and each successive ply stepped in, so the repair is thickest where the original laminate was thickest. Chopped strand builds thickness and conforms to curves. Biaxial carries the tensile load the original woven roving was carrying.
5. Wet out, consolidate, and cure. Resin is catalyzed by weight to the manufacturer ratio for shop temperature, typically a little over one percent methyl ethyl ketone peroxide for polyester, and each ply is rolled with an aluminum grooved laminating roller until no air remains. Vinyl ester is used where water exposure or flex is a factor.
6. Fair the surface. Once cured, the repair is ground flush and faired with a polyester glaze rather than a thick filler. High spots are blocked with 80 then 180 grit on a long board so the repair matches the panel contour rather than the immediate area.
7. Gelcoat and finish. Matched gelcoat is sprayed in multiple passes to full film thickness, either with a wax additive or under a polyvinyl alcohol film so the surface cures fully. It is then wet sanded from 600 up through 2000 grit and machine polished to the gloss of the surrounding panel.

Front cap and rear cap replacement

When a cap is cracked across a large area, has multiple failed prior repairs, or has geometry too complex to rebuild by hand, replacement is the better economic answer. Caps are molded parts, so replacement returns the original contour exactly instead of approximating it.

The job is mostly disassembly. The windshield or rear window comes out, the marker lights and clearance lights are disconnected and labeled, the roof membrane is released back to the termination point, and the cap flange is separated from the sidewall and roof structure. Caps are bonded and mechanically fastened, so the release has to be done in a sequence that does not damage the mating flange we are bonding back to.

Availability is the constraint owners are least prepared for. A cap is a large, low volume molded part, and on older or discontinued models it may not exist. When it does not, we go back to hand layup over a rebuilt substructure, which is more labor but is the only path that keeps the coach original in shape. Fitment is checked dry, with the cap clamped in position and every fastener hole verified, before any adhesive is opened.

Bonding uses a high modulus polyurethane adhesive on structural flanges and a lower modulus sealant such as Sikaflex 221 on non-structural seams, with the bond surfaces abraded and primed to the adhesive maker specification. Mechanical fasteners hold clamping load while the adhesive cures rather than carrying the joint by themselves.

What this costs and how we quote it

Fiberglass work is quoted in body hours, materials, and refinish hours, with the material line more significant than on most body repairs because resin, reinforcement, and gelcoat are consumed by area and thickness rather than estimated as a percentage of labor. A repair that is wide but shallow uses far more material than one that is small and deep.

The variable that moves the number most is the scarf ratio. Because the taper is twelve times the laminate thickness on every side, a small hole in a thick laminate produces a surprisingly large prepared area, and that area drives both the layup hours and the gelcoat and polish hours after it. Cap replacement is quoted separately as a parts-driven job with heavy disassembly labor. Our labor rates and the paid estimate that starts the process are on the pricing page.

Vehicles we perform this on

Fiberglass construction varies enormously between platforms, and the layup schedule we use is matched to what the panel actually is.

• Class A diesel pushers, where full body molded caps and thick laminate sidewalls are the norm
• Class C motorhomes, where the cabover cap sees the most stress cracking of any panel on the vehicle
• Travel trailers with filon skins, which are thin and bonded and need a different schedule than a solid laminate
• Truck campers, where the roof-to-side radius cracks from repeated loading and unloading cycles
• Food trucks and mobile business bodies, where fiberglass service compartments take daily contact damage

If this damage is on an insurance claim

Fiberglass repair is claimable when the cause was a covered event: something struck the panel, or a storm did. It is generally not claimable when the cause was gradual, which covers crazing, print-through, ultraviolet degradation, and the slow propagation of a stress crack that started at a molded corner. Adjusters look for a date of loss and a mechanism, and a panel that failed from geometry has neither. What we can do is document the cause honestly with photographs of the crack origin and the surrounding laminate, so a covered portion of the damage is not lost inside an uncovered one. Our page on what insurance excludes explains the gradual cause distinction in detail.

Why Brea owners bring this work to us

The drive from Brea to the shop in Yorba Linda takes most owners about fifteen minutes, and composite work is multi-day work regardless of size, so an easy drop-off matters more than proximity to the mile.

Two practical differences. First, laminate work happens in a temperature controlled area kept in the range polyester and vinyl ester resins are formulated to cure in, because a laminate that cures cold never reaches its designed strength and one that cures too hot gels before it is consolidated. Second, gelcoat spraying is kept physically separate from the paint line. Gelcoat additives and paint systems contaminate each other, and shops that spray both from the same booth end up with fisheyes in one or slow cure in the other.

Frequently asked questions