Body Repair for West Covina Owners

What RV body repair covers that an automotive shop does not handle

Automotive body shops are built around unibody cars: steel and aluminum stampings, known repair procedures, standardized parts and a lift that fits in a 12 foot bay. An RV shares almost none of that. The body is a laminated sandwich of skin, insulation, framing and interior panel, built on a chassis that came from a different manufacturer, using parts that may or may not still be produced. A car shop can do beautiful work and still be the wrong shop for this vehicle.

The practical differences show up immediately. There is no straightening bench that a 40 foot coach fits on. Panel replacement means dealing with a bonded laminate rather than unbolting a fender. Access behind a damaged sidewall usually requires removing interior cabinetry, wall panels or an entire slide room. And damage that looks purely cosmetic frequently turns out to have broken the vapor barrier, which starts a water intrusion problem that will do more damage over the next two years than the impact did.

So RV body repair is the intersection of collision work, structural work and carpentry. We repair the skin, we repair or replace what is behind it, we restore the seal, and only then do we refinish. Doing those in the wrong order produces a vehicle that looks correct at pickup and delaminates the following summer.

How RV and trailer bodies are actually built

Most travel trailers, fifth wheels and lower to mid range motorhomes use a laminated sidewall. From outside in: filon or aluminum skin, adhesive, foam block insulation with aluminum or wood framing set into it, more adhesive, then a thin luan or azdel interior panel. The whole sandwich is pressed together in a vacuum press, and the resulting panel gets its strength from the bond rather than from any single layer.

That construction is light, strong for its weight, and unforgiving of damage. Break the bond in one area and the panel loses stiffness locally, which is what a soft spot is. Break the outer skin and moisture reaches the foam and the framing, and once the framing is wet the bond starts letting go from the inside out. This is why we always check for a breach even on damage that looks superficial.

Higher line coaches and bus conversions use different construction: welded steel or aluminum cage framing with fiberglass or aluminum skin hung on it, more like a bus body. Those repair more conventionally but require welding and often structural inspection behind the panel. Cargo vans and box trucks are different again, being either monocoque steel bodies or aluminum and composite panel boxes on a truck chassis. We repair all of them, and the estimate names which construction your vehicle uses because it changes both hours and method.

• Laminated: filon or aluminum skin over foam and framing over luan or azdel, bonded in a press
• Framed: welded steel or aluminum cage with skin hung on it, common on high line coaches and conversions
• Monocoque steel: cargo vans, where the body panel is the structure
• Panel box: aluminum or composite panels on a truck chassis, common on box trucks and reefer bodies

Dents, creases and the limits of pushing metal back out

A shallow dent in an aluminum skin with clean access behind it can sometimes be worked out with careful pressure and heat, then finished with a thin skim of filler. That is the best case and it is not the common case, because on most RVs there is no access behind the skin without opening the interior.

Creases are harder than dents. A crease means the material has stretched along a line, and stretched metal does not simply return. Pushing it out leaves the panel long, which shows up as an oil can effect where the area flexes in and out under hand pressure. The correct repair is either to shrink the stretched area, which works on steel and is limited on aluminum, or to accept filler over a properly supported panel, or to replace the section.

Fiberglass and filon behave differently again. They do not dent so much as crack, star or delaminate. A fiberglass cap that took an impact may look like it only has a scuff while the laminate behind it has separated across two feet. We sound the panel by tapping across it, listening for the dull tone that means the bond has released, and we map the actual affected area before quoting anything.

Four materials, four repair processes, frequently on the same vehicle

Aluminum skin repairs by working the panel where access allows, by replacing a section between rivet lines or seams where it does not, and by careful preparation before refinishing because bare aluminum oxidizes within minutes. Aluminum also work hardens, so a panel that has been pushed back and forth a few times becomes brittle in exactly the place you are trying to fix.

Fiberglass repairs by grinding back to sound laminate, building the area back up with cloth and resin in stepped layers, then filling and fairing to the original contour. Done right the repaired area is stronger than the surrounding panel. Done wrong, meaning filler over a crack without laminating, it reappears through the paint within a year.

Filon repairs are a hybrid. The skin is thin fiberglass and can be repaired like fiberglass, but the substrate behind it is luan or azdel and may be wet or crushed. That has to be addressed from behind, which is why filon repairs on a trailer sidewall frequently involve removing interior panels.

Steel, found on truck cabs, service bodies, bumpers and frames, repairs conventionally: pull, straighten, shrink, weld in replacement sections and finish. The critical rule is that rust does not get covered. Corroded material gets cut out and replaced with new steel, welded and sealed, because corrosion continues under a coating and reappears having done twice as much damage.

Sidewall damage that hides structural damage behind it

The most expensive mistake in RV body work is repairing the skin and stopping there. An impact that dents an aluminum sidewall transmits force into the aluminum or wood framing behind it, and a bent stud or a cracked wall member does not announce itself from outside. We open damaged areas rather than guessing, because a repaired skin over a bent frame member sits slightly wrong forever and the finish shows it in raking light.

Corners are the highest risk area on any RV. The rear cap corners, the front cap corners and the transitions where a sidewall meets a roof edge all carry framing junctions, and they are also where backing incidents happen. Corner damage should always be opened and inspected. We have found broken framing behind what looked like nothing more than a scuffed cap on more occasions than owners expect.

Slide rooms are the other high risk area. A slide box hit while extended transmits force straight into the slide mechanism, the rails and the room framing. The room may still move, and it may still look fine, and it may be running out of square in a way that destroys the seals over the following year. Any slide involved in an impact gets checked for square and operation before we call the job done.

Insurance body claims and the supplement conversation

Most RV body claims start with an adjuster estimate written from photographs or from a brief walk around. That estimate reflects what was visible. It almost never reflects what teardown reveals, because on a laminated body the visible damage is the smallest part of the story.

The process that works is straightforward. We write our own estimate at the shop, we tear down the damaged area and photograph what is behind it, and we submit a supplement with documentation for anything the original estimate missed. Carriers expect this. Supplements on RV claims are routine, not adversarial, as long as the documentation is real. Collision estimates are written at the shop and insurance walk ins are welcome during business hours.

The part owners should understand is timing. A supplement pauses the job while the carrier reviews and approves. That is normal and it is worth waiting for, because starting repairs on unapproved damage puts you in the position of arguing about it after the fact. We tell you when a supplement goes out and we tell you when it comes back.

Body repair on vans, box trucks and work vehicles

Cargo vans, Sprinter vans, box trucks, flatbeds and service bodies come through for body, paint and structural work. A Sprinter that clipped a loading dock, a box truck with a torn lower rail and crushed corner post, a cargo van with a full length scrape down the quarter panel, a flatbed with a damaged headboard: those are ordinary jobs here.

Box bodies are their own discipline. Aluminum panel bodies repair by replacing damaged panels between posts, and the corner posts and rails are structural, so damage there gets addressed properly rather than skinned over. Composite and insulated bodies add a layer, since the panel is bonded to a core and a puncture that reaches the core has to be sealed or the panel wets out. Roll up doors, swing doors, rails and hardware all get checked for operation after body work near them.

One thing to be clear about: we do body, paint, structural and equipment installation work on commercial vehicles. We are not a truck engine or drivetrain shop and we do not perform compliance inspections. If your unit needs mechanical service, get that handled by your mechanical provider and bring us the body work.

What actually delays a body job

Three things, in order. Parts availability is the biggest. RV manufacturers change suppliers constantly and stop supporting older models, so a compartment door for a 2011 coach may simply not exist. When that happens we fabricate, adapt a similar part, or repair the original, and each of those takes longer than bolting on a new one. Special order parts require a deposit at the time of order, and that deposit is not refundable, so we confirm fitment before ordering.

Second is hidden damage discovered at teardown, which triggers the supplement cycle described above. Third is the refinish sequence itself, since the vehicle needs booth time, and booth time on a full length coach is scheduled as a block rather than squeezed between other work.

What does not usually delay a job is the actual body work. Our body technicians and our paint department are in the same building, so a vehicle does not travel between vendors and nobody waits on a subcontractor's schedule. If you need the rig back by a specific date for a trip, tell the estimator at the start and we will tell you honestly whether that date is realistic. Call (949) 799-3387 and ask before you commit to the trip.