Fibreglass boat repair: hulls, decks, RIBs and jet skis.
From a gelcoat chip on the topsides to a hole below the waterline, most damage to a GRP boat can be repaired. Whether it is worth doing comes down to how far the damage runs and what the boat is worth.
- ORIGINAL LAMINATE
- NEW LAMINATE
- TAPERED EDGE
- GELCOAT
- BLISTERS
GRP boats and craft we repair.
Hulls
Impact damage, holes, cracks, gouges and blistering in GRP hulls, above and below the waterline.
Decks
Stress cracks and crazing, soft or spongy areas, and damage around deck fittings.
RIBs
The rigid GRP hull, deck and console of a RIB: chips, cracks and impact damage.
Inflatable tube repair: to be confirmed · placeholderJet skis
Cracked, holed or gouged hulls and top decks. Tell us the make, model and year: hull materials vary between manufacturers, and a repair has to suit the material.
Gelcoat, laminate and core: what fails on a GRP boat.
Chips, scratches and gouges
Damage to the gelcoat. Cosmetic at first, but the gelcoat is what keeps moisture and sunlight away from the laminate.
Crazing and stress cracks
Fine cracks that appear gradually and worsen are usually caused by flexing — often near a bulkhead, at the curve where deck meets cabin, or around a window. The longer a panel flexes, the deeper the cracks go.
Chalking and oxidation
A faded, chalky surface caused by long exposure to sun and seawater.
Osmosis and blistering
Water works into a polyester laminate, reacts with soluble material inside it and forms blisters under the gelcoat. It is a chemical process that can degrade the resin, not just a surface blemish, and it ranges from a few isolated blisters to thousands.
Delamination
Layers of laminate, or a skin and its core, separate. The sign is a soft, spongy deck, or a dull thud when tapped instead of a crisp ring. Leaks at deck fittings are the most common cause.
Impact damage
A small hole on the outside can hide much more behind it: damaged bulkheads and internal structure are often out of sight behind linings.
From a polish to a rebuilt laminate.
What a marine repair involves depends on which of these you have. A structural repair typically runs like this.
Full osmosis treatment: availability to be confirmed · placeholder
- 01Assess, inside and outTapping, probing and moisture readings establish how far the damage extends and whether a core is wet. With impact damage that can mean removing linings to see behind, so a structural estimate may come in two stages.
- 02Cut back to sound laminateDamaged material is removed and the edges are ground to a long taper, so the new laminate bonds across a wide area.
- 03RebuildNew glass and resin are laid up to restore the thickness and strength of the original. A wet or rotted core is replaced; where the core is dry and the skin intact, the skin can sometimes be re-bonded.
- 04FairThe repair is filled and faired back to the original shape.
- 05Gelcoat and polishGelcoat or paint is applied, sanded through progressively finer grades, then compounded and polished.
Where the work happens.
On site
Larger boats are usually repaired where they are kept. Tell us whether the boat is afloat or ashore and what access there is: work below the waterline needs the boat out of the water, and outdoor work needs dry conditions while the repair cures.
In our workshop
Trailable boats, RIBs, jet skis and removable parts can come to our workshop, where a repair cures under cover.
- On-site coverage area: to be confirmed · placeholder
- Workshop address: to be confirmed · placeholder
- Largest boat the workshop can take: to be confirmed · placeholder
Almost anything can be rebuilt. Whether it should be is about cost.
Repair usually makes sense when
- The damage is to the gelcoat or a limited area of laminate.
- The structure behind — bulkheads, stringers, core — is sound, or can be made sound.
- Blisters are few and isolated: something to plan for, not an emergency.
- The cost sits comfortably within the value of the boat.
Think carefully when
- The cost of repair approaches the value of the boat — the point at which an insurer starts to treat it as a write-off.
- A core or internal structure is wet or rotted over a wide area.
- Cutting back keeps revealing more damage.
Hidden damage is the main uncertainty: a full figure may not be possible until the area has been opened up. If an insurer or surveyor is involved, say so when you enquire.
What to tell us.
- Boat type, make and approximate age.
- Whether the hull or deck is solid laminate or cored, if you know.
- Where the damage is: topsides, below the waterline, deck or transom.
- Photos: outside and, if you can reach it, inside.
- Whether the boat is afloat or ashore, and where it is kept.
- Any moisture readings or surveyor's report.
- The gelcoat colour or colour code, if known.
- Whether it is an insurance claim.
Fibreglass boat repair questions.
Can gelcoat chips and scratches be repaired without repainting the boat?
Yes. Local damage is filled with gelcoat, sanded and polished back. Matching the colour is the hard part, because the gelcoat around it has aged.
Will the repair be invisible?
Not necessarily. Existing gelcoat fades and weathers, so new gelcoat in the original colour can still look different beside it. A close match is the realistic aim; sometimes refinishing a wider area gives a better result.
What is osmosis?
Water penetrates a polyester laminate and reacts with soluble materials inside it, forming blisters under the gelcoat. It is a chemical process — the fluid in the blisters can attack the resin — not a purely cosmetic one.
Is osmosis serious?
A few isolated blisters are a reason to plan, not to panic. With widespread blistering the concern is the condition of the laminate beneath and the effect on the boat's value. It takes a very severe case to threaten watertightness.
How is osmosis treated?
In outline: the hull is assessed, the affected gelcoat is removed, the laminate is washed and dried thoroughly, then it is rebuilt where necessary, sealed and recoated. Drying time varies widely from hull to hull, so time and cost can only follow an inspection.
What is delamination, and how would I know?
It is layers of laminate, or a skin and its core, coming apart. A deck feels soft or spongy underfoot and sounds dull when tapped. A wet core is often behind it.
Can a hole in a GRP hull be repaired?
Yes, including large ones. The damage is cut back to sound laminate and the hull rebuilt in layers. Whether it is worth doing is a question of cost against the value of the boat.
Do you repair RIBs and jet skis?
Where they are GRP, yes: a RIB's hull, deck and console, and jet-ski hulls and decks. Some jet skis are not, so tell us the make, model and year.
Not quite what you have?
Tell us about the boat and the damage.
Type, age, where the damage is and where the boat is kept — and we'll come back to you about a repair.