This article covers the build of the actual hull and superstructure of the yacht. It also covers the primary construction for the carpentry interior. In addition, other miscellaneous “hull” tasks which take place throughout the build process.
Lamination of the Hull – Stage 1
Selene construct their yachts with FRP – fibre re-enforced plastic. This basically means its made of fibre glass. The superstructure is manufactured using two different techniques – hand-laid lamination together with vacuum resin infusion, depending on the component.
The process starts with a mould. They first lay a barrier coat into the mould, which helps when it comes to release. The next layer is the gel coat layer which is sprayed inside the mould. This is the outside “shiny” layer for fibreglass which ultimately gives the boat a great look. The workers then manually lay layer upon layer of fibreglass matting, rolled and brushed with resin, over and over again. This creates the strong structure of the hull shell itself.
The hull is reinforced with longitudinal stringers (wooden frame) running full length on both port and starboard sides of the boat. There is also a transverse frame system. The stringer system re-enforces the strength of the hull.
Release of the Hull
Once the hull has been laid it needs to cure for approximately 6 weeks. The same applies to the other FRP modules. During this time, the resin will harden into the fibre matting and form the strong shell. The FRP will continue to “dry out” for up to about 2 years after it is released from the mould.
Once the curing process has completed, the hull can be released from the mould. This is done by breaking apart the two halves of the mould and lifting the fibreglass shell out. During construction, the shell is supported by chains attached to a crane on the ceiling of the lamination hall. This supports the hull while the tractor pulls the mould away.
The hull shell is then placed onto a cradle. It will remain here until the boat has completed the first stage of the build process.
Bulkheads
There are three water-tight bulkheads which are built in as the mould is done. Four “walls” which are part of the solid structure of the hull. The idea is that if one of them is breached (for example by hitting something underwater and putting a hole in the hull), then the boat will remain afloat. Water ingress will be contained in just one compartment.
Infusion Techniques for Decks
For some components of the boat, Selene use a different process called vacuum infusion. This technique is used on thinner or flat components, like a deck or floor. It involves encasing the component mould in a type of heavy duty cling-film, then creating a vacuum by sucking all the air from the plastic bag. This vacuum then draws the resin into all the small cracks and parts of the mould. Creating fibre glass in this way results in a very strong, but thin, component.
FRP Module Sections
There are four main parts making up the boat superstructure. It starts with the shell of the hull, and the “lid” which is the deck layer. The flybridge deck component is then added on the top, which incorporate the roof and windows of the saloon. The stern section of the boat is a separate moulded piece and is the curved part of the cruiser stern, which ties together the hull and the upper sections.
There are several further small pieces – such as the hard top and the radar tree and engine access floor. Gradually they are all bonded together and the boat then takes shape.
The hull shell remains on the cradle throughout the build process. Each piece is released separately from its mould and add to the hull shell. Over the course of about 6-9 months, the whole boat begins to take shape. The various sections are joined together with special filler, bonding and hand laid fibreglass – in the end you can’t see the joins and it becomes one seamless boat.
Bulbous Bow
We have taken the optional extra of a bulbous bow – which most owners now take. A bulbous bow is a “bulb” which protrudes from the bow of the boat, under the water line. It’s purpose is to change the way the boat cuts through the water to reduce drag. This improves fuel efficiency and speed and is supposed to improve stability of the boat.
The bulbous bow is moulded into the hull with an extra piece added on at the initial stage. It therefore forms a seamless join.
General research on cruising yachts seems to favour the benefits of a bulbous bow. Selene’s biggest competitor, Nordhavn, carried out a study on several different models of their yachts. On all of them there was some increase in efficiency and up to 12% on a boat our size. We didn’t really think too much about this option as it seemed to be an obvious choice. The downside is that there is reported to be an increase in slapping noise of the bow against the water.
Tanks – Fuel and Water
At the same time as the hull is being laid and is curing, the yard construct the various tanks. These tanks are laid into the hull section as the very first task, so they need to be ready. The fuel tanks, in our case, are made of aluminium and the water tanks are stainless steel. They are fabricated in the Selene metal workshop. The waste water tanks are FRP – so these are also made in the fibreglass workshop. Not all boats they build have stainless steel or aluminium tanks. Often they make all the tanks from FRP – so something to check if you have a feeling one way or the other!
Once the hull shell has been released from the mould she is placed on the cradle. One of the first tasks is to fit the fuel tanks as these sit well down inside the bilges. The rest of the boat is then built around them.
Water tanks and waste tanks are in the bilges underneath the floors. Therefore, again, these are fitted before the deck floor components are placed on top. We also had to think further ahead to our electronics installation – since we wanted different tank sensors to the standard Selene gauges, we had to make sure these were built it at the right stage as well.
Cable Loom
The other task which is completed before other work is the running of the cable and hose loom from the bow back to the stern. Given the need for the sealed engine compartment, several large conduits – like big drain pipes – are attached to the hull. Power cables and hoses run inside the conduits, and the engine room wall is built on top – so it should not be necessary to later drill holes to connect up equipment.
Coloured Hull
We want our hull to be painted dark blue – as a first choice. Or perhaps a mid-grey colour, which is a bit more practical in terms of keeping it clean. However, Selene do not want to paint the hull – even though it is one of their standard options. Selene have had some issues with blisters and bad finish on painted hulls because in the humidity of China and the dust of the shipyard, it’s difficult for them to guarantee the quality.
There are two ways to achieve a coloured hull – the first is to use a coloured gel coat. When the mould is released the gel coat layer is the visible layer on the outside. This method is generally used in mass production boats and gives lower quality results in the long term. Gel coat is harder to match colour when there are small damages – because the gel coat discolours over time. It is also dulls and fades very easily.
The second method is to paint with a special marine hull paint, such as Awlgrip. Paint gives a far superior finish quality but it is harder to apply. A good finish requires good spray hall conditions after the hull has been completed.
We’ll paint later …..
Selene’s persuasion tactic to us was based on the fact that a paint job should be done 2 years after the release of the hull from the mould. Of course as things turned out, our boat was nearly 4 years in production so there would have been plenty of time. But we decided not to take the chance of a bad job anyway. We will do the painting at a professional paintspray hall later on our journey.
As a compromise, the yard offered to give us a light grey gel coat free of charge. They happened to have some stock of a light grey remaining which had been left over from another boat. Just enough for our gel coat layer, and better than a plain white boat in the meantime.
The grey colour is REALLY light grey! It is hardly noticeable but depends on the sunlight on the hull. Still – better than plain white for the meantime. But we will be going for that proper paint job at the earliest opportunity as I really hate white boats!
Primary Carpentry
One the best skills of the shipyard is their carpentry. They are used to working almost entirely by hand to create beautiful cabinetry from raw planks of teak. There may well be some gaps in their knowledge and experience when it comes to modern technical machinery and electronics, but their carpentry cannot be faulted.
There are two different ways of working – depending on how busy the shipyard is with new boat builds. When the lamination hall is busy, the carpentry team can build the base wooden interiors in a modular form outside the boat. Then when the hull is released, the modules can be lifted in complete – which speeds up the process. When the yard is quieter, the base carpentry can also be build in situ inside the hull. We had a combination of the two techniques with our boat.
The raw cabinets are built from marine ply, then real wood laminate is applied and also solid wood fittings. All the shapes and curves are made by hand at the shipyard and, to be frank, the results are stunning. When the cabinetry is complete on one level then it is “sprayed” – which is the first layer of varnish to seal in the wood. From this point onwards, the interior takes on a completely different feel.
Teak Decks and Caprails
We chose the option for teak decks everywhere aft of the Portuguese bridge. This means the swim platform, cockpit, side decks, flybridge helm area and cockpit stairs. We may well regret this in the long term – but we very much like how NEW teak looks (not grey teak)! On our previous sailyacht, we had artificial teak which of course kept its colour but was not as durable as the real thing.
The teak decks were laid fairly early on in the process. Since the boat did stand still for some time, the teak went very quickly grey. The varnish on the teak caprails, which run on top of the railing all around the saloon deck, also very quickly deteriorated in the sun. These caprails are standard in teak. We have seen some other owners in Europe replace the teak caprails with stainless steel. With hindsight this may well be a better option but the teak does look nice when it’s properly treated. We’ll see.
Just before the boat left the shipyard, the decks and the caprails were completely sanded down to bare wood by the yard. We supplied them with a teak treatment product – Starbrite Natural Tropical Sealer – which we had to import to China. The teak came up again nicely – we will have to see how often it needs to be sanded and treated ourselves.
Anti-Fouling
Once the boat is complete in the main construction hall, it is taken on it’s cradle out into the fresh air and into the paint shed. All Selene yachts come with anti-fouling paint as standard – but we have chosen to use CopperCoat on Destiny. CopperCoat is an excellent product which we have had on our previous yachts – successfully and unsuccessfully. It is essential to follow the manufacturer instructions absolutely to the letter. This means hull preparation – sanding and epoxy undercoat, and the method of application of the top CopperCoat. We worked with one boatyard in Europe who believed they knew better, and unfortunately the whole boat had to be redone at their cost. We didn’t want Selene to make the same mistake.
Result still not great ….
They did listen to the instructions and they did get advice from the local CopperCoat dealer. However, they did not follow as closely as necessary for the sanding and preparation of the hull. In particular in relation to the filler areas where the different hull components were joined.
On top of this, due to the pandemic, Destiny did lay in the water at the shipyard without moving for almost a year. In the dirty water of the river delta, in tidal depths where we discovered later she sank in the mud at low tide.
As a result the yard had to completely strip the anti-fouling and redo the work, when they lifted the boat after lockdown. See the detailed article for photos and full information on this particular drama! Needless to say, when we received Destiny, the hull was properly re-painted as it should be.
As always, we will add more links and more detail as we gather together our experiences and sort through the thousands of photos we’ve taken in the last four years! If you have any questions, just post them below or get in touch with us directly – we’re always happy to help if we can.