RV fiberglass and delamination repair

A crack is the fiberglass itself failing, usually from impact or from stress at a corner where a window or a cap meets a flat. It is repaired by grinding back to sound material, laying up, and refinishing.

Delamination is the skin still being intact while the adhesive holding it to the substrate has released. The panel looks bubbled or wavy and feels hollow. Nothing is broken, and that is exactly why filling and painting it does nothing.

A flat palm and a coin will tell you more than looking will. Sound bonded panel returns a tight, dead tap. Released panel returns a hollow one, and the boundary between the two sounds is the actual size of the problem. It is almost always larger than the visible bubble.

That twenty minute test at intake is what decides whether the job is an injection repair, a panel replacement, or a full sidewall. Committing to a number before doing it is how a repair goes over.

Older coaches use lauan, a thin plywood, which swells and delaminates permanently once wet. Newer ones often use Azdel, a composite that does not absorb water the same way. Which one you have changes both whether the substrate can be saved and how the repair is scoped.

Finding wet lauan usually widens the job, because the water that released the adhesive has also been in the framing. That is a supplement conversation, and documenting the moisture is what supports it.

Caps take the impact in most collisions and are frequently unavailable. On a coach out of production the mould may no longer exist, in which case fabrication is faster than waiting for a part that is not coming. Documenting the unavailability is what gets fabrication approved on a claim.

Delamination is the repair owners most often decide against, and sometimes that is the correct decision. A small released area on a coach that is otherwise sound is straightforward work. A sidewall that is hollow from the front cap to the rear on a twenty year old trailer is a rebuild, and the rebuild can exceed what the unit is worth on a forecourt.

What tips it either way is usually the substrate rather than the size. Released adhesive over dry, sound material is a bonding repair. Released adhesive over swollen lauan means the water that caused it is still in the wall, and the honest scope includes framing nobody has seen yet. That is the moment to have the conversation about whether to spend the money at all.

A coach kept for twenty years by an owner who knows it is a different calculation from a unit bought last spring. We can only tell you what the repair costs and what it does not fix. The rest is yours.

Say delamination to an adjuster and the first thing they hear is water, and water over time is maintenance rather than a sudden loss. That reflex is often right and sometimes badly wrong, because impact delaminates panels too. A side swipe that leaves a scuff can release bonding a metre either side of the mark without breaking the outer skin at all.

The way through is to establish the cause rather than to argue about the label. Impact delamination has a mechanical boundary that follows the load path. Water delamination follows a seam, a window frame or a roof edge, and it is usually accompanied by staining and by soft substrate. Which one you have is decidable, and it is decidable on the first visit.

A laminated motorhome sidewall is a bonded sandwich and behaves as a structural panel, so a large released area affects how the shell carries load, not only how it looks. On a travel trailer the panel is thinner and the framing behind it lighter, which means the same release travels further and reaches the floor sooner.

An aluminium skinned coach does not delaminate at all in this sense, because there is no laminate. What it does instead is work at the rivets and open its seams, and the repair is a metal trade with different tooling and a different set of skills. Owners of vintage riveted trailers who are told they have delamination have usually been told by somebody guessing.

Photographs of a bubbled panel are less useful than owners expect, because the visible bubble and the actual boundary are different shapes and only one of them is in the picture. What does travel well is a description of what the panel sounds like and where the sound changes.

• A photograph of the whole side from far enough back to show where the panel waves
• A close frame of any seam, window corner or roof edge nearest the affected area
• Whether the hollow sound stops at a frame member or keeps going
• Whether the interior wall behind it is stained, soft or smells damp
• The model year and whether the coach has been stored outdoors
• Any previous repair to that panel, including anything done by a previous owner