A Cap Nobody Makes Anymore, Moulded From the Other Side of the Coach

A dealer body shop told the owner of a mid 2000s diesel pusher that his coach was a total loss. The reason given was that the front cap is not available.

That is a true statement about parts availability and a false conclusion about the vehicle. Discontinued does not mean unrepairable. It means fabricated.

What was actually wrong

Front cap damage from a low speed frontal impact. Cracking radiating from the passenger side lower corner up toward the windshield opening, a section of the lower cap missing entirely, and the cap to sidewall seam opened on that side for about four feet.

Structurally the coach was sound. Chassis measured within specification. The sidewall laminate had some debonding at the opened seam, which is expected, but nothing dramatic.

So the whole determination rested on one unavailable part.

How you mould a part that does not exist

Two routes, and which one you use depends on what survived.

From the surviving side. RV caps are usually broadly symmetrical about the centreline. If the damage is confined to one side, the undamaged side is a pattern for the damaged one, mirrored. You take a mould off the good side, mirror it, and lay up the replacement section.

This is the better route when it is available because the pattern is from the actual vehicle, so it fits.

From a donor pattern. Where both sides are damaged, or where the damage crosses the centreline, you need a pattern from another coach of the same model. That means finding one, which is the slow part, and taking a mould off it without damaging someone else's vehicle.

On this coach the passenger side was damaged and the driver side was intact, so route one.

The stages

Pattern preparation. The surviving side is cleaned, any imperfections addressed, and release agent applied. This is fussy work because every flaw in the pattern becomes a flaw in the part.

Mould lay up. A mould is built off the pattern in stages, allowing cure between layers. Then it is removed, trimmed and reinforced so it holds its shape.

Part lay up. The replacement section is laid up in the mould, gelcoat first, then reinforcement in layers to the correct thickness schedule. Cure between stages.

Trimming and fitting. The part comes out, gets trimmed, and then gets fitted to the vehicle. This is where you find out whether the pattern work was good, and it always needs adjustment.

Bonding and structural attachment. The section is bonded and mechanically fastened to the surviving cap and sidewall, with the joint built as a structural laminate rather than a filled seam.

Refinish. Because the joint has to disappear, and because a moulded section will not match adjacent gelcoat, this is a panel refinish job rather than a spot repair.

What it cost

• Fiberglass cap section repair: within $750 to $12,000 and up at 4 to 60 labor hours
• Full cap replacement including moulding: $4,500 to $25,000 and up at 30 to 120 labor hours
• Delamination repair at the opened seam: within $1,500 to $20,000 and up
• Refinish across the front and both forward side panels

This job landed at 94 labor hours and just over $23,000 including materials and refinish. At $210 per hour body and paint, plus $55 per paint hour materials.

Against a coach the owner valued at considerably more than that, with a sound chassis and an interior he had spent money on. Straightforward decision once the number existed.

Why we tell people the honest version

Not every one of these makes sense.

If that same coach had needed the cap plus a roof at $4,500 to $22,000 plus sidewall delamination at $1,500 to $20,000 plus floor at $1,200 to $12,000, we would have added it up, put it next to the vehicle value, and told him to take the settlement.

We do that regularly and it costs us work. The alternative is someone spending forty thousand dollars over three years discovering the total in pieces, and that is a worse outcome for everybody including us.

What this capability means practically

If a shop tells you a repair is impossible because a part is unavailable, ask whether they fabricate. Many do not, and for them the statement is accurate.

We mould fiberglass cap and panel sections in house and we form aluminum skin panels here. That turns a dead end into a schedule, which is a different problem and a solvable one.

It also means the answer on an older coach is almost always yes it can be done, followed immediately by here is what it costs. The first half is not useful without the second half.