# A marker light penetration that shows a soft spot: cause, cost and calendar

A clearance lamp is a nine dollar part sitting in a hole cut through a laminated sidewall, and most coaches carry eight to fourteen of them. What a soft spot costs at $285 and what it costs at $25,000.

## A nine dollar lamp sits in a structural hole

Nobody inspects clearance lamps. They are lighting, they cost less than a tank of propane,
and when one stops working an owner replaces it in ten minutes with a screwdriver. That
framing is the problem, because a marker lamp is not really a light fitting on a laminated
coach. It is a hole.

A laminated sidewall is a bonded sandwich: gelcoat or printed skin, fiberglass, foam or
lauan core, inner panel. Mounting a marker lamp means cutting through the outer skin into
that core, running two wires through, and setting two screws into material that has no
business getting wet. The only thing standing between the core and the weather is a bead of
butyl or sealant a couple of millimetres thick.

So a soft spot beside a lamp is not a lighting complaint. It is a report that the core has
been wet long enough to lose its bond with the skin, and the lamp is simply the doorway it
came through. Treating it as an electrical item is how a $400 reseal becomes a five figure
panel.

## Press beside the lens and count how slowly it returns

Do this with the flat of your thumb, not a fingertip, about an inch outside the lamp base.
Sound laminate does not move. A wall that gives a sixteenth to an eighth of an inch and
then returns slowly, with a faint sound like a soft drum, has released its bond in that
area. Work outward in a spiral and mark the edge of the movement with low tack tape.

Then read the surface at a low angle. Stand at the front of the coach and sight down the
sidewall with the sun behind you. Delaminated areas show as a dull patch, a slight oil
canning, or a quilted look where the skin has taken a set between framing members. Around
a leaking lamp that patch is usually a teardrop, wider below the lamp than above it.

Three smaller tells confirm it. Screw heads standing proud or spinning without loading up.
A crescent gap at the top edge of the lens where a shrinking sealant bead pulled away from
the highest and thinnest part of the joint. And a tea coloured streak weeping below the
lamp on a white panel, which is core material leaching out of the hole.

## Marine layer dew, not rain, is what fills a laminated wall

Owners who store outdoors in Hacienda Heights reasonably conclude that a wall cannot be
getting wet, because it barely rains. The water is not coming from storms. It is coming
from the marine layer that pushes inland overnight through the spring and early summer,
condensing on a cold skin and running down it every morning for weeks.

That produces exactly the wrong loading for a marker lamp joint. Dew wets the surface for
several hours at low pressure, which is ideal for capillary entry into a thinned bead, and
then the afternoon sun bakes the panel dry from outside while the moisture that got in sits
in the core. Water goes in overnight and is trapped, rather than in and out with a
rainstorm.

The sun then finishes the job on the seal itself. On a coach parked with one flank facing
west, that side takes hours of direct afternoon load, and the exposed sealant bead at each
lens hardens and shrinks years ahead of the shaded side. This is why the streetside and
curbside of the same coach routinely fail on different schedules, and why we look at the
west facing wall first.

## How many penetrations does your sidewall actually carry?

Count them. Most travel trailers and fifth wheels carry eight to fourteen marker and
clearance lamps, plus scare lights, a docking light, receptacle covers, city water inlets,
cable and satellite plates, hitch covers and a slide fascia. That is twenty to thirty
individual holes through a laminated wall, each one held by a bead of sealant with a
finite service life.

Two facts follow from the arithmetic. First, the odds that all thirty are sound at year ten
are low, which is why an annual seal walk on a coach stored outdoors is worth more than any
single repair. Annual maintenance service runs $400 to $2,500 at 3 to 10 hours and a seal
walk is part of it.

Second, the failure is almost never the one you would guess. Owners obsess over the roof
and the windows and neglect thirty small penetrations at eye level. Roof and seal
inspection at $285 to $900 covers both, and the sidewall findings are usually the ones that
surprise people.

## The $285 reading and the $25,000 sidewall

Caught at the reseal stage, the work is small. The lamp comes off, the old bead is cut out
rather than caulked over, the hole edges and the wire pass are sealed, moisture is read
around the opening, and the lamp is rebedded. Any wiring corrosion falls under 12 volt
electrical repair at $285 to $5,000 plus, and often the whole visit is an hour of labor and
a lamp.

Caught with an active soft spot, the range opens. Soft spot and water damage repair runs
$750 to $18,000 plus at 5 to 80 plus hours because the scope depends entirely on how far
the bond released and whether framing behind it is affected. Delamination repair runs
$1,500 to $20,000 plus. Both are structural tier work at 3 to 8 weeks.

Caught late enough that the skin has to come off, aluminum skin and sidewall replacement
runs $2,500 to $25,000 plus at 16 to 120 plus hours, plus decal and graphics replacement at
$500 to $5,500 to restore the print. Moisture and leak detection is $285 to $1,200 at 1 to
5 hours and it is the reading that tells you which of those three you are in. It is priced
and credited against an authorized repair.

## Filon width is what sets the calendar, not the lamp

Here is the part owners never anticipate. The lamp is a commodity. Standard clearance and
marker lamps from the usual suppliers are on a shelf, they cost a few dollars, and they are
never the reason a job takes six weeks. The constraint is the skin.

Printed fiberglass sidewall skin is manufactured in specific widths and specific surface
textures, and it is bonded to a coach as a full height sheet. Matching an existing wall
means matching width, thickness, texture and print. A current production skin in a common
width moves in days to two weeks. A superseded texture, an unusual width or a printed
graphic panel from a discontinued floorplan runs two to six weeks, sometimes more, and
occasionally it is not available at all, which turns the repair into a paint and graphics
job instead of a panel job.

That check happens during evaluation, before a date is quoted. We look up the skin
availability and the print, price both paths, and tell you which one the calendar supports.
Special order material carries a 100 percent deposit at order and that deposit is not
refundable, so nothing gets ordered before the reading is done.

## Is a soft spot ever a covered loss?

Usually not on its own. Water that entered through a shrinking sealant bead across six
seasons is wear, and wear sits outside what a comprehensive policy responds to. That is a
structural feature of how these policies are written rather than a judgment about anyone,
and a claim on the gradual version tends to produce a denial that reads correctly.

It responds when something happened. A branch tore the lamp off, another vehicle contacted
the side, freeway debris broke the lens, hail cracked it. Then the water entry is
consequential to a covered event, and the useful documentation is what proves the event:
dated photographs, the impact pattern, and the extent of new wetting.

The recurring difficulty is that a photograph cannot show a released bond line, so a first
estimate written from photos captures the lens and misses the panel. Have moisture readings
taken on a grid with the meter and the location both in frame, and ask that the readings and
images be attached to the file rather than summarized. A measurement gives a reviewer
something to evaluate. A description of a soft area does not.

## Book the moisture reading before summer ends

Walk the coach this week with three things: a thumb, a roll of low tack tape and a phone.
Press outward from every lamp, plate and inlet on both flanks. Tape the boundary of any
movement you find. Photograph each taped area with the date on, and photograph the sealant
bead at the top edge of every lens, because that is where shrinkage shows first.

Do it before the end of the dry season rather than after the first rain. A soft spot mapped
in September and resealed in October is a small job. The same spot found in February has
had a winter of water in it, and the structural tier calendar of 3 to 8 weeks lands in the
middle of the season you wanted to use the coach.

If any area gives, bring it in for a reading rather than caulking over the bead. We are
18.4 miles from Hacienda Heights, 24 to 38 minutes via SR-60 west to Fullerton Rd, or
SR-60 to SR-57 south to SR-91 east. All evaluation and repair happens at the Yorba Linda
facility and we do not travel to the coach. Call (949) 799-3387 with the coach year, the
wall construction and how large the soft area measures.

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Source: https://ocrv.club/blog/marker-light-penetration-shows-a-soft-spot-hacienda-heights
OCRV Center, 23281 La Palma Ave, Yorba Linda, CA 92887
Phone (949) 799-3387. Email info@ocrvcenter.com.
Serving Hacienda Heights and the surrounding area. 18.4 miles, 24 to 38 minutes via SR-60 west to Fullerton Rd, then south to La Palma Ave.
In shop work only. All estimates are priced and credited against an authorized repair.
