Fiberglass Repair from Rancho Santa Margarita to Our Yorba Linda Bays
Written by Refinish Department Lead, Paint and Refinish Lead, OCRV Center. Reviewed by Structural Repair Lead
In shortComposite failures divide by depth: surface, bond line, or core. Press the panel and listen to it. Repairs run $750 to $25,000+ in the heated composite bay.
What kinds of fiberglass damage can actually be repaired?
Fiberglass repair at our Yorba Linda facility covers gelcoat cracks, punctures, separated laminate, wet core and whole panel replacement on coaches from Rancho Santa Margarita. The repair path is set by depth: surface damage refinishes, bond failures get rebuilt, and wet core means the panel comes off.
- A bubble that moves under hand pressure is a bond failure, not a dent
- Chalky gelcoat that will not shine again is a refinish, not a polish
- Wet lauan or foam behind a panel changes the job entirely
- Composite work needs heat and time, which is why it queues
- Price range
- $750 to $25,000+4 to 120 labor hours at $210 per hour
- Labor rate
- $210 per hourBody and paint department
- Typical stall time
- 5 to 30 shop daysCure schedules cannot be compressed
- Moisture testing
- Tramex and Delmhorst metersReadings recorded at a grid, not spot checked
- Written estimate
- $150Credited in full against an authorized repair
- Bay conditions
- Heated composite bayLaminating resin cures to spec instead of to ambient
Last verified
Almost every fiberglass question we get is really a question about depth. The owner sees a mark, a bubble or a dull patch, and what they need to know is how far into the wall it goes. That single fact separates a two day refinish from a three week panel replacement, and it is knowable in about fifteen minutes with a knuckle, a moisture meter and a flashlight held at a low angle.
Work down the table. Each row corresponds to a different depth of failure and points at the page that covers the repair for that depth. If you can press on the damage and feel it move, skip ahead to the delamination row, because that is a bond failure and it does not stay the same size.
Which of these do you need?
| What the panel is doing | Where it belongs | How deep it goes |
|---|---|---|
| Chalky white residue on your hand, no shine returns after washing | Fiberglass restoration and refinishing | Gelcoat surface only |
| Star crack radiating from a screw, or a puncture from road debris | Crack, hole and impact repair | Through gelcoat into the laminate |
| Cracked radius on a molded front or rear cap after a strike | RV and camper fiberglass repair | Molded component, structural at the corner |
| Bubble or ripple that moves under hand pressure | Delamination repair | Bond line between skin and core |
| Soft over several feet, meter reads wet, wall gives underfoot | Full fiberglass panel replacement | Core is gone, skin has nothing to hold |
| Hollow tap sound spreading each season with no impact history | Delamination repair | Progressive bond failure, will not stop on its own |
Schedule of work
What is actually behind the fiberglass on your unit
The word fiberglass covers at least three different constructions on the units that come through here, and they fail in unrelated ways. A laminated sidewall is a sandwich: a thin filon or Lamilux skin, a core of block foam or lauan, aluminum or wood framing, and interior paneling, all pressed together and bonded as one panel. A molded cap is a thick single skin laid up in a mold with reinforcement at the radii. And an older unit may have a hand laid shell with no core at all.
That is why a bubble on a laminated wall and a crack on a molded cap have nothing to do with each other. The bubble is a bond that let go and it will grow every hot week. The crack is a stress fracture being fed by flex and it will keep running until you stop drill it. Same material, opposite problems, and quoting them the same way is how owners end up paying twice.
- Laminated sidewall: skin, core, frame, interior panel, bonded as one
- Molded cap: thick single skin with reinforcement at every radius
- Azdel composite backing: does not absorb water the way lauan does
- Hand laid shell on vintage units: repairable but nothing matches off a roll
Molded caps, skirts and the parts that come off a mold
Front and rear caps, wheel skirts, fender flares and slide fascias are molded rather than laminated, and they crack instead of delaminating. The crack almost never starts where the impact landed. It starts at the nearest radius or fastener, because that is where the flex concentrates, and it will keep running until the ends are stop drilled and the section is laminated from the back where access allows. Sourcing a replacement is the real problem: caps for units more than eight years old are routinely discontinued.
The bubble that moves when you press it
Put a hand flat on it. If the surface deflects and springs back, the skin has separated from what is behind it, and that is a bond failure rather than a dent. It happens where water got between the layers, where the original adhesive was starved, or where thermal cycling has simply worked the joint apart over a decade of Southern California summers. The important property is that it spreads. A hand sized soft spot in spring is regularly a two foot soft spot by the following autumn, and the repair cost tracks the area.
Holes, star cracks and things that hit you at speed
Debris off the toll road, a branch on a canyon road, a ladder that came off a truck ahead of you: the damage is local, the boundary is obvious and the substrate around it is usually sound. These repairs are about preparation rather than volume. The hole gets bevelled back to a wide taper so the new laminate has bonding area, reinforcement is laid up in stages rather than in one thick pour, and the finish is blended outward far enough that the eye never finds the edge.
When there is nothing left to bond to
Once the core behind a panel is wet across a large area, the skin has nothing to hold onto and no amount of injected adhesive changes that. The tell is a wall that gives underfoot on a slide floor, a meter reading wet on a grid rather than at one point, or a hollow tone that carries for four feet in every direction. The panel comes off, the framing and decking get replaced, and new skin goes on. It is the most expensive path on this page and the one most often postponed into being worse.
When the wall is sound and only the surface has died
Gelcoat is a pigmented resin, not a paint film, and ultraviolet exposure breaks the resin at the surface until the pigment sits loose. That is the chalk that comes off on your hand. The structure underneath is usually perfect. The repair is mechanical: cut the dead layer back through progressive abrasives until you reach sound resin, then refine and protect it. Where too little material remains, refinishing in a modern coating system is the honest answer instead of chasing a shine that is no longer there.
Why composite jobs sit in the building longer than they work
Laminating resin cures on its own schedule. You can add technicians to a body job and finish sooner. You cannot add technicians to a cure. That is the honest explanation for why a fiberglass repair with 30 labor hours occupies a bay for two weeks, and it is why we run a heated composite bay rather than laminating in whatever the building temperature happens to be.
Temperature control is not a luxury here. Resin cured cold stays soft and telegraphs the repair boundary the first hot week in August. Resin cured too fast in a hot bay exotherms and prints through as a shrunken outline. Holding the bay at a controlled temperature is the difference between a repair nobody can find and a repair you can see from the far side of a parking lot.
Note
Anyone quoting a laminated sidewall repair in two days is planning to fill it rather than rebuild it. That repair will show a shadow line by the following summer.
What a composite repair actually costs
This work bills from the body and paint department at $210 per hour, with paint supplies at $55 per paint hour and body supplies at $5 per body hour. Parts carry standard markup, and sales tax applies to parts and materials while labor is not taxed. Written estimates are $150 and credit in full against an authorized repair.
Area drives the number more than severity does. A puncture the size of a fist and a puncture the size of a dinner plate cost almost the same, because the preparation, cure and blend dominate. Double the delaminated area, though, and you double nearly everything. That is why we sound the whole panel before quoting instead of measuring the visible mark, and why an owner who waits a season regularly finds the price has moved by thousands.
On cost
Jobs over $2,000 take a 50 percent deposit at authorization. Special order molded caps require a full non refundable deposit at order because they are not returnable.
Getting a carrier to look at a bonded wall correctly
The recurring argument in this category is cause. Carriers pay for sudden events and decline wear, and delamination sits awkwardly across that line because it can be caused by either. A wall that let go after a documented hail event or a covered water intrusion is a claim. A wall that let go because a roof seam has not been resealed since the unit was new is maintenance, and saying otherwise wastes everyone's month.
What decides it in practice is the record made before anything comes apart. Sounding survey photographs with a tape in frame, moisture readings on a grid with dates, and a note on the roof condition above the failure. Adjusters approve findings and argue with assertions, and in this category the finding is a moisture map.
On the claim
Osmotic blistering and sun degraded gelcoat are excluded on every RV policy we bill. If we find them alongside covered damage, they are separated and quoted to you directly.
Units this bay sees most
Towables dominate the composite bay. Travel trailers and fifth wheels are built with the thinnest skins and the most seams, so they show bond failure earliest. Class C units come in for cab over cap cracks, slide in truck campers arrive with corner separation from flexing on the truck bed, and vintage coaches come in for hand laid work nobody else wants to attempt because there is no panel to order.
What is included
- Sounding survey and boundary mapping
- The panel is tapped outward from the damage until the tone goes bright again, and that line gets taped. The estimate is written to the tape rather than to the visible mark.
- Moisture readings on a grid
- Tramex and Delmhorst readings taken at fixed intervals across the panel and recorded. A single spot reading can miss a wet zone by two feet.
- Substrate identification before scope
- Azdel behaves nothing like lauan when it gets wet, and filon behaves nothing like a molded cap. What the wall is built from decides what the repair costs.
- Laminating and bonding in the heated bay
- Resin cures at specified temperature rather than at whatever the building happens to be that week, which is what keeps a repair from reading through in August.
- Gelcoat or basecoat finish to match
- Repairs are finished in the same system the panel was built in, then blended into adjacent surfaces rather than stopped at a hard edge.
- Sealant restoration at every reopened seamwhere applicable
- Runs we open get stripped and rebedded rather than skimmed, because a composite repair that leaks has not actually finished.
How the work runs
Sound the panel and map the real boundary
30 minutes
A knuckle finds bond failure faster than any instrument. The tap goes dull where the skin has let go and bright where it has not. We walk that boundary outward and mark it, and it is almost always larger than the owner expects.
Take moisture readings and identify the substrate
45 minutes
Meter readings go on a grid and get written down. At the same time we determine whether the wall is Azdel, lauan or block foam, because a wet lauan wall and a wet Azdel wall are different repairs with different prices.
Write the scope to the depth, not the mark
1 hour
Surface, bond line and core are three separate scopes. We put in writing which one applies and what would move it to the next tier, so a discovery mid repair is a documented possibility rather than a surprise.
Open, dry, rebuild and bond
6 to 90 hours
Failed material comes out, wet core is replaced, and new laminate goes back with the correct resin, open time and clamp pressure. This is the stage where heat and patience decide whether the repair holds for a decade.
Finish, blend and verify
4 to 25 hours
Gelcoat or basecoat goes on, the repair is blended into the surrounding panels, and any seam we opened is rebedded and water tested before the unit is released.
What this costs
$750 to $25,000+
4 to 120 labor hours at $210 per hour, body and paint.
- Paint supplies at $55 per paint hour.
- Body supplies at $5 per body hour.
- Parts at $100 or less carry 100 percent markup. Parts over $100 carry 35 percent. Special order parts require a full non refundable deposit at order.
- Sales tax of 7.75 percent applies to parts and materials. Labor is not taxed.
- A 50 percent deposit is taken at authorization on any job over $2,000, with an additional 25 percent when parts arrive on any job over $10,000. Final balance is due at pickup.
- A single star crack around a fastener on a white gelcoat trailer sits at the bottom.
- A full sidewall replaced on a 40 foot painted coach sits at the top.
- Discontinued molded caps drive both the price and the schedule more than the labor does.
How estimating is billed
- Written repair estimate: $150, credited in full against an authorized repair.
- In depth diagnostic, scan and programming: $285 per hour, one hour minimum, credited in full against an authorized repair.
- In shop pre purchase inspection: $400 to $1,200 depending on unit size and systems count.
- Insurance walk ins are accepted during posted hours. All inspection and estimating work is performed in shop at the Yorba Linda facility.
Turnaround and shop capacity
Typical turnaround is 5 to 30 shop days. Composite work runs on cure schedules that cannot be shortened by adding people. A crack repair is five to eight shop days. A full sidewall with core replacement is three to six weeks, and longer when a molded panel has to be sourced or built.
Equipment this work runs on
- Heated composite bay held at laminating temperature year round
- Tramex Dead On and Delmhorst BD-2100 moisture meters for grid mapping
- Vacuum bagging setup with resin trap for large laminate rebuilds
- Infrared cure lamps for localized post cure on vertical panels
- Gelcoat spray equipment separate from the basecoat line to avoid contamination
- Long board and guide coat station for flatting a rebuilt panel
How insurance treats this work
- Usually covered
- Impact punctures, debris strikes, hail bruising and delamination that follows a documented water intrusion event from a covered loss are all payable, including the refinish work needed to blend the repaired area.
- Usually not covered
- Delamination from a roof seam that was never maintained, gelcoat chalking from sun exposure and osmotic blistering are all treated as wear. No carrier pays for a wall that failed because the sealant above it was twelve years old.
- Where supplements come from
- Very high. The visible mark is smaller than the failure on nearly every bonded panel, so the real boundary is not known until the skin comes off. Photographing the sounding survey before teardown is what converts that into an approved supplement.
Which vehicles we do this on
Vehicles we perform Fiberglass on
Travel TrailerTravel trailer repair covers A frame tongue welds, the front cap that takes road debris, the roof front radius seam, sidewall delamination starting at a window corner, and equalizer and axle wearStandardStandard fifth wheel repair concentrates on the pin box and upper deck welds, the floor at the step up transition, the front cap above the pin and the roof front radius seamClass CClass C motorhome repair centers on the cabover bunk, the joint where the coach body meets the factory van cab, and the stick built or laminated house behind itClass A GasClass A gas motorhome repair covers the molded front and rear caps, the vacuum bonded laminated sidewalls, the EPDM roof and the F53 chassis underneathTruck CamperSlide in truck camper repair concentrates on the wing walls, the jack brackets bolted through them, the cabover nose over the truck cab and the tie down attachment pointsVintage and ClassicVintage coach work means riveted aluminum or stick and tin construction over timber or steel framing, bedded in butyl rather than bondedAppendix: questions and answers
- Is a bubble in my RV sidewall urgent or can it wait a season?
- It spreads, so waiting costs money rather than saving it. A bond failure grows with every heat cycle and every mile of road flex. A hand sized soft spot in March is commonly a two foot area by October, and the price tracks the area almost exactly.
- Do the delamination injection kits sold online actually work?
- They can bond a small area back if the core behind it is dry and sound. They do nothing at all when the core is wet, which is the situation in most walls that have gone soft. Injecting adhesive into wet lauan traps the water and guarantees the repair fails again.
- Does an Azdel wall change the repair compared with lauan?
- Substantially. Azdel is a polypropylene composite backing that does not absorb water or rot, so a wet Azdel wall usually dries and rebonds while a wet lauan wall has to be cut out and replaced. Identifying which one you have is the first thing we do, not an afterthought.
- What happens if the molded cap for my unit is discontinued?
- We repair the original or build a replacement section from a mold taken off the existing part. Caps for units older than about eight years are frequently unavailable, and this is the single most common reason a fiberglass job runs into weeks rather than days.
- Can new gelcoat be matched to a twenty year old sidewall?
- Matched exactly, no. Blended so the transition is invisible, yes. Aged gelcoat has shifted in both color and gloss, so we tint to the current condition and feather the repair across enough surface that the eye never lands on an edge. Stopping at a panel line is what makes a repair obvious.
- What moisture reading means my wall is actually wet?
- We compare against a known dry area on the same unit rather than an absolute number, because meter readings vary with substrate. A zone reading substantially above the dry reference across a grid is wet. One elevated point next to a fastener is usually a fastener, not a flooded wall.
- Why can I not just use a fiberglass repair kit from the hardware store?
- Polyester kits shrink as they cure and they do not bond reliably to the vinyl ester and adhesive systems used on RV walls. The patch looks acceptable for a season, then telegraphs a shrunken outline and lets go at the edges, and the second repair costs more than the first would have.
- What actually slows down composite failure on a stored unit?
- Keep water off the seams and heat off the surface. Inspect and rebed roof and sidewall sealant annually, cover or shade the unit through summer, and address a chalky surface before it etches. Most of the walls we replace failed above the damage, at a seam nobody had touched in a decade.
Open a file on this repair
Tell us the vehicle, what happened and whether a claim is open. We will tell you what the scope looks like and what it takes to get you back on the road.
Or call (949) 799-3387