---
title: "Fender and Quarter Skin Repair | Rancho Santa Margarita"
description: "Fiberglass wheel skirts on motorhomes, steel fenders on Sprinters, riveted quarter skins on box bodies. $210 per hour, sectioning done to OEM procedure."
focus_keyword: "fender and quarter skin repair rancho santa margarita"
canonical: https://ocrv.me/services/body-repair/fender-and-quarter-panel-repair/
kind: subService
updated: 2026-07-29
source: OCRV Center
---

# Fender and Quarter Skin Repair on Motorhomes, Vans and Box Trucks

> On a motorhome the fender is **molded fiberglass** screwed into a skirt. On a Sprinter it is **stamped steel** with a factory seam. Two trades, one page, $750 to $8,500+.

## How does fender and quarter skin repair differ between an RV and a van?

Fender and quarter skin repair on a motorhome is fiberglass work: grinding, laminating, fairing and refinishing a molded skirt. On a Sprinter or box truck it is metal work with sectioning, welding or riveting. Our Yorba Linda shop runs both, and Rancho Santa Margarita owners get told which one they have at estimate.

- Motorhome fenders are molded fiberglass, not bolt on stampings
- Sprinter rear quarters section at factory seams to OEM procedure
- Box truck corners are riveted skins over formed posts
- Cracks on RV skirts usually start at a screw hole, not at the impact

### Key facts

| Item | Value |
| --- | --- |
| Price range | $750 to $8,500+ (4 to 40 labor hours at $210 per hour) |
| Labor rate | $210 per hour (Body and paint department) |
| Typical turnaround | 3 to 12 shop days (Metal sectioning and corrosion protection add days over a fiberglass repair) |
| Materials | $55 per paint hour, $5 per body hour (Weld through primer and cavity wax included on metal sectioning) |
| Written estimate | $150 (Credited in full against an authorized repair) |

Curb contact is the most common way this damage arrives. A tight canyon turn off Santa Margarita Parkway, a driveway apron taken at the wrong angle, a fuel island kerb that was closer than the mirror suggested. The tire clears, the skirt does not, and the result is a scrape running the length of a wheel opening with cracks fanning out from the screw line above it.

What happens next depends entirely on what that skirt is made of. Motorhomes, fifth wheels and trailers carry molded fiberglass or filon over the wheel opening, screwed into the sidewall through a trim insert. Sprinters, cargo vans and chassis cabs carry stamped steel or aluminum with real flanges and factory seams. Box and reefer bodies carry riveted skins over formed corner posts. Three materials, three trades, and the estimate looks different for each.

## The word fender means two unrelated parts here

On a motorhome, a fifth wheel or a travel trailer, the fender is a molded fiberglass skirt or a section of laminated filon covering the wheel opening. It is screwed into the sidewall through a trim channel and it carries no structural load. Nothing bolts off. Repair is a composite trade: grinding, scarfing, laminating, fairing and refinishing.

On a Sprinter, a cargo van or a chassis cab, the front fender is a stamped panel bolted to the body with a sealer bead at the flange, and the rear quarter is welded structure that forms part of the body shell. Repair is a metal trade with published section locations, specified weld processes and a corrosion protection sequence that is not optional. On a box or reefer body it is a third thing again: a riveted skin over formed posts, where the fastener pattern is the joint.

**What a wheel opening is made of, by vehicle**

| Vehicle | Fender or quarter material | Repair trade |
| --- | --- | --- |
| Class A and Class C motorhome | Molded fiberglass skirt over sidewall | Composite laminating and refinish |
| Travel trailer and fifth wheel | Filon skirt bonded to substrate | Rebond, fair and refinish |
| Sprinter and cargo van | Bolt on steel fender, welded rear quarter | Metal sectioning and corrosion protection |
| Box and reefer body | Riveted aluminum or FRP over posts | Skin replacement and fastener renewal |

## Why the crack rarely starts where the curb hit

Composite skirts fail at their fasteners far more often than at their impact points. A screw driven a quarter turn too far dishes the washer and puts a permanent compressive stress into a brittle laminate. Road vibration then does the rest, and a hairline appears at the hole and travels. When a curb strike happens later, the panel breaks along the path that was already prepared.

That is why our repair includes stop drilling every crack terminus and changing the hardware at reassembly. Fender washers spread the clamp load and a controlled torque means the panel is held rather than crushed. It costs almost nothing and it is the difference between a repair that lasts and a repair that reappears at the same screw in eighteen months.

## Sectioning metal quarters to manufacturer procedure

A modern van body is engineered to fold in a specific way, and the panel joints are part of that design. Manufacturers publish where a quarter may be sectioned, what weld process is required at each flange, and where structural adhesive substitutes for or supplements a weld. Squeeze type resistance spot welding is specified at many of those joints because it reproduces the factory nugget rather than approximating it.

Cutting outside those locations produces a body that looks correct and behaves differently under load. We follow the published procedure, and where a job calls for it, we would rather replace a full quarter than section one in a location the manufacturer does not sanction. For a fleet running Sprinters on daily routes, that is not a philosophical point, it is the difference between a repaired van and a compromised one.

## Corrosion protection is most of the difference in a metal repair

Cheap quarter and fender repairs come back as rust, and they come back from the inside. Any time metal is cut, welded or drilled, bare steel is exposed inside a cavity that will never be seen again. Weld through primer at the joint, cavity wax injected into the closed section, and isolation between aluminum and steel are what keep that from becoming a problem two winters later.

The coastal air in this part of Orange County is not kind to a poorly protected seam, and units that spend time near the water accelerate it further. We treat this sequence as part of the repair rather than as an upgrade, and it is written into the estimate as its own operation so nobody has to guess whether it happened.

> **warning:** If an estimate for a welded quarter repair has no line for cavity wax or weld through primer, ask why. Those two operations are the difference between a ten year repair and a three year one.

## Graphics that run across a wheel opening

Wheel arches are exactly where coach designers like to put a sweep, and that turns a modest skirt repair into a layout exercise. We measure the stripe geometry off the undamaged side of the unit before any sanding starts, because once the graphic is gone there is nothing left to reference except photographs and hope.

On decal schemes the fix may be reproduction vinyl. On sprayed schemes it is masking and multi stage color, which is slower and carries more paint hours. Either way it is called out separately in the estimate, because an owner comparing two quotes deserves to know which one included the stripe.

## Wheel well liners, clearance and what happens after the repair

The liner behind a fender is not trim. It is what stops road grit, water and thrown stones from blasting the back of the panel at highway speed. A missing or torn liner is why plenty of skirts fail from the inside years before anything hits them from the outside, and it is one of the most common items left off a cheap repair because it is invisible once the wheel goes back on.

Clearance is the other post repair check. A skirt or arch pushed inward by an impact can sit close enough to a tire that it only makes contact under load or in a turn, which produces a rub mark an owner discovers weeks later. We measure clearance at full lock and at ride height before releasing the vehicle, and on dual rear axles we check between the tires as well, because that gap is where a heat damaged repair usually shows up first.

> **note:** Ask whether the wheel well liner is included. It is the least visible line on a fender estimate and the one that most affects how long the repair lasts.

## Tire failures, curb strikes and how carriers see them

A blown dual on a diesel pusher does remarkable damage in a very short distance. The casing takes the skirt, the wheel well liner, frequently a section of the laminated wall above it and sometimes the wiring loom routed along the frame. That is a covered event on most policies and it should be documented as one incident with a full scope, not repaired piecemeal as it is discovered.

Curb strikes are more contested. Single vehicle contact with a fixed object generally falls under collision coverage, and a deductible often makes a modest skirt repair not worth filing. We will tell you honestly which side of that line an estimate lands on, because sending an owner into a claim that costs them more than the repair helps nobody.

## Cost

$750 to $8,500+, based on 4 to 40 labor hours at $210 per hour.

Written repair estimate is $150, credited in full against an authorized repair. All work is performed in shop.

## Questions and answers

### Is an RV fender the same kind of part as a car fender?

No. On a motorhome or trailer it is a molded fiberglass or filon skirt screwed into the sidewall through a trim channel, carrying no structural load and offering nothing to unbolt. On a Sprinter or chassis cab it genuinely is a stamped panel with a bolt pattern and a flange sealer bead.

### Why does the crack in my fender skirt keep coming back?

Usually because the crack ends were never stop drilled and the fastener that started it went back in the same way. A hairline under filler keeps travelling. We drill each terminus, laminate from behind, then reassemble with fender washers and controlled torque so the panel is clamped instead of crushed.

### Can you section my Sprinter quarter anywhere convenient?

No. The manufacturer publishes allowable section locations and specifies the joining process at each one, including where squeeze type resistance spot welds are required. Cutting outside those locations changes how the body behaves under load, so we either section where permitted or replace the full quarter.

### A rear dual blew out and tore up the skirt. What is the real scope?

Usually more than the skirt. A shredded casing at highway speed typically takes the wheel well liner, a section of laminated sidewall above the arch, and often wiring routed along the frame rail. It should be documented and claimed as one incident rather than repaired as each item is discovered.

### The corner of my box body flexes in the wind. Is that just rivets?

It is the fastener pattern giving up. Holes elongate, the skin works against the post, and water tracks in at the same corner. The fix is a new skin section refastened on a fresh pattern with Huck bolts or structural blind fasteners, plus isolation between aluminum skin and steel structure.

### Is a curb scrape on the skirt worth filing on insurance?

Often not. Single vehicle contact with a fixed object generally falls under collision, and a typical deductible can approach or exceed the repair. We write the estimate first so you can see the number before deciding, and we will say plainly when filing would cost you more than paying.

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Source: [OCRV Center](https://ocrv.me/services/body-repair/fender-and-quarter-panel-repair/). Last verified 2026-07-29.