HOW A HALLBERG-RASSY HULL IS BUILT

This is what the mould to a hull looks like. The outside is reinforced with strong metal stringers. The inside has a high glossy finish. The mould is made in two parts, which allows us to build the hulls with an integrated rubbing strake on the hull and a deep bilge. This would not be possible if the mould was built in one part.

The hull is laid up from the outside and in. We start to mask the part of the hull that will be blue. The inside of the mould is made in a contrast colour. This makes it easier to see that you have put correct thickness of gelcoat.

The gelcoat is based on isophtalic resin. The isophtalic resin is very resistant to water penetration and keeps its glossy finish very well. The white gelcoat is sprayed on. White for the hull and blue gelcoat for the Hallberg-Rassy stripe. A vinylester based barrier coat is applied. This makes the laminate more resistant to water penetration, and at the same time it protects against print through, which is if the glass fibre would be visible in the surface finish.

Compared to the single skin hulls in the old days, today's hulls are insulated, which means a superior torsional stiffness of the hull.

The material used for insulation is a PVC foam called Divinycell. It is fitted when the laminate is still wet, and then covered by laminate. The Divinycell is a superior material for a cruising boat, compared to balsa. The PVC foam has closed cells, which means that the material does not absorb water. Divinycell is a superb insulation against cold, heat and noise. The Divinycell will finally be covered with more laminate.

Here the lower rudder bearings are laminated in place. Those bearings are spherical, self adjusting, which means the rudeers are alwyas easy to move, even under very high load.

The parts of the hull are laminated together before the mould is opened. The points where the parts are put together are laminated so carefully that this will be the strongest part of the hull.

The decks are built in the same way as the hulls. Divinycell used as a core material and strong backing plates that are laminated into the deck under deck hardware.

All laminate is carefully rolled out by hand. Temperature and humidity is strictly controlled during the process and registered together with batch numbers, start and stop times, employee numbers and so on in a log book.

The grid system is an advanced design that reinforces the hull under the waterline. The grid distributes loads from the bottom out in the hull in case of grounding. There is a steel beam moulded athwartship under the mast support (34-44 ft) or keel stepped mast (50-69 ft) to carry the strong loads. The grid will also be the support for the floorboards.

The rudderposts are made of solid stainless steel.

The shafts are laminated into the rudders, by vacuum lamination, forming solid, very strong rudders.

The grid is bonded into the hull.

Many models have the hull grid not only below the sole boards but all the way up to the deck level, for superior torsial stiffness and the possibility to install bulkheads further apart and lower for a more open interior.

A metal frame is used when the bulkheads are laminated to the hull.

All structural bulkheads are laminated from both sides, forward and aft, to the hull, deck and superstructure, which gives additional strength.

Deck and hull are laminated together. This is made from the inside. This is a Hallberg-Rassy typical feature, introduced already 1968. The method gives a superior torsial stiffness and cannot leak. The coaming between hull and deck is covered by a beautiful teak cap rail. On boats 37 ft and larger, the fittings for the stanchions will be installed onto the toe rail coaming. The structural bulkheads are laminated to the deck and superstructure from both sides. The inside of the hull is painted twice with topcoat.

Another hull is now ready for transport to the main yard in Ellös on island Orust. All hulls are trucked to the main yard. All equipment like tanks, engine and joinery will come down through the companion hatch. Everything that goes down in the boat can go out without having to take the boat apart. 
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