17.1. The marine plywood
It’s the most commonly used wood in the boatbuilding industry. Most of the arrangements are made of marine plywood. As it name suggests, it’s made of several thin “plies” or layers of wood. Each ply crosses the following one at 90° angle. This solution compensates for the wood deformations. The plies are glued together under high temperature and pressure. The glue is resistant to humidity. The outer final surface of the panels is made of a noble wood, such as okoumè. The designer will later chose how to finish the surface: it could be covered with Formica, fabric, leather of a thin layer of wood called scaleboard, roughly 2 millimetres thick, which could be teak, mahogany, walnut etcetera.
The plywood edges absorb water: they should never be left on sight but should be finished by means of glued wood slats. The designer might need to insert wood gratings in his design, like for the fan-coils inlets and outlets, or for the lockers ventilation. Gratings should not be cut from a plywood panel: the wood layers would show on the edges. It’s cheap but ugly. Gratings should be made of solid wood. Marine plywood is quite heavy: its specific weight is 0.45. As an alternative the designer could use the light material I mentioned in 16.2.
17.2. The solid wood
The solid wood isn’t much used for boatbuilding, apart for the framework and for some details of the furniture. Solid wood has the annoying tendency to shrink, to bend, to crack, to stretch. In other words, it might bring a lot of headaches if it’s not perfectly seasoned. The example in figure # 80 shows a rounded edge, made of solid wood. It goes without saying that the same wood type must be used for the scaleboards and the solid wood details.
17.3. The briar
The real “briar” comes from the root of the homonymous plant. Pipe smokers know it well because it’s what the chamber of their pipes is made of. Several other types of wood are called “briar”, but they come from different trees and never from their roots. The briar comes from sections of the trees where branches have been cut or where parasites have caused some kind of illness. These parts are machine-sliced and the outcome are thin wood sheets with beautiful patterns. The size of the sheets of briar wood is small (roughly 25 by 35 centimetres) and the producer must tie them together with the same order by which they were cut, so that their pattern is consecutive. Briar should be used with moderation. First of all, the briar wood is beautiful if it appears here and there, as a precious element of decoration. A whole arrangement made of briar is sickening, like an indigestion of caviar. Then:
the briar wood sheets are small and have irregular shaped edges. Therefore the woodworking is time consuming and needs very qualified manpower. The briar wood sheets are full of small holes: these imperfections need repairing, and it’s a wearing procedure. Briar wood is a rare material, and the designer should avoid choosing some kind of wood that’s not easily available: please stay down to heart. Commonly used briar woods are the Brazilian walnut, the manzanita, the myrtle, the mahogany, the walnut, the oak and the California redwood. All of these names might sound unfamiliar, unless one of my readers is the woodworker’s son. I suggest that the beginner visits a joiner’s workshop and humbly asks to be given some scrape of wood, may be also asking for more info, such as how, why and where it’s used. I’m sure that nobody would refuse a piece of waste. The same procedure could be used in a marble workshop because
Principle number twenty: you cannot be an interior designer unless you’re familiar with the materials. and expensive. The market has found two cheaper and more available types of wood which resemble mahogany. They’re called “assie mahogany” and “sapele mahogany”. Actually assie and sapele have nothing to do with real mahogany but I must honestly admit that they’re quite similar to the original.
Also walnut has an alter ego, called anegrè. Even teak has a lookalike: the iroko. This wood is more yellow that teak and its cutting dust is highly allergenic. The surface of all woods can be processed in several ways: it can be whitened, painted or even sandblasted. The outcome is very different and the designer had better have some sample done before making a final decision. It’s impossible to write a short summary about all the existing types of wood: I just wish to highlight that pale woods, such as birch, ash, linden and oak tend to change colour when exposed to direct light. Try and leave a magazine for a week on an ashwood table under the sunlight. Its mark will clearly show when you remove it. Some types of wood are harder than others and less workable, some aren’t available in long boards, but only in short ones etcetera. The topic is vast and fascinating: I suggest the beginner to examine it in depth, not only for professional reasons but also for personal culture. It could be the discovery of a fabulous world.
17.5. The stonework
Three families actually fall under the name “stone”: marbles, granites and stones. They’re different for their genesis, mechanical characteristics, grain, solidity, workability and mainly for their
hardness. The hardness of a stone is measured in “Mohs” grades: the soft talc value is 1, the hard diamond is 10. Marble goes from 3 to 4; granite from 6 to 7. The designer should not choose a stone just from a small sample. This should be only a primary criterion, after which the designer should visit the marble workshop and check the actual stone leaf because the colour and the veining might sensibly change from one stone block to another. The designer can find the most complete catalogue of stones in cathedrals. Go there and try to identify the marbles, the granites and the stones. The most commonly used stone is marble. There are plenty, of different types, with an incredible variety of colours and patterns. They range from the Carrara pure white to the light blue of the macauba and Bahia; from the Portugal pink to the Siena yellow; from the Indian absolute black to the Greek crystal, which is semi-transparent. The total weight of the ship should be kept under strict control: to save weight, the marble leafs are cut in thin slices and then glued on a bee-nest aluminium and epoxy resin structure. Only a few details are made of solid marble, like the torus. Granites are much harder than marble, and therefore less workable. Stones are much softer and less lasting. Their microcrystalline cohesion is feeble and they easily break, and yet some of them are beautiful. Some stones aren’t fit for use on board a vessel: for example the limestone or even the Carrara pure white, which is stunning but far too delicate. The stone surface can be treated in several different ways, thus getting quite diverse colours and effects. What follows is a short list of the possible treatments:
• smoothing;
• sandblasting;
• bushhammering;
• chipping;
• polishing.
The designer should have some samples of the surface treatment done: they’re all handmade and the result might be sensibly different from one hand to another.
17.6. The fabrics
As I wrote before, the fabrics must be fire resistant (Class 1). The fabrics are among the most noticeable features of an arrangement: there are the curtains, the sofas, the bedspreads and much more. The final decision about the vessel’s look is up to the designer’s sensibility and to the customer’s taste. The upholstery could be made of classic damask cloths, or of a monastic white linens sequence. I just wish to suggest that, in any case, the designer should specify that the fabrics must be wetted before they’re cut and sawn. This way the fabric won’t ever shrink and the customer won’t complain. Please check which is the height of the cloth: if it’s too low, a lot of joints will be necessary. The design pattern must match and it can become a serious headache. Besides, there are a lot of scraps. Check also the cloth weight: some fabrics are extremely light, and others are as tough as a tin foil. The choice depends from what they’re used for.
17.7. The leather
The leather is a wonderful and noble material. It smells good and transforms all rooms into a cosy nest. The leather quality and thickness changes with the part of the animal’s skin it’s made of, and also
with the way it’s treated. Commonly it’s cows leather, but it could be pigs, horses, goats, snakes, eels, toads and much more. Its top quality is the “fine grain” which saves the original porous surface of the animal’s skin. Then there is the “coarse grain”, which is lightly fluffed. Then again the “nubuk”, with velvet-like surface. The “split” can be used for cladding pieces of furniture. The upper part of the leather cut through its thickness becomes the fine grain and the lower part is the split, less precious.
“Leather” is the natural uncut skin. The industry offers embossed leathers; dotted, striped, with relief patterns… you name it. The use of leather depends from the designer’s taste and, why not, from is ethic position towards animals. In case, my suggestion is to use only the fine grain, the best and softer leather. The leather upkeep needs more care than the fabrics’, but on the other side it’s elastically isotropic. In other words it resists and stretches homogenously in all directions, while fabric resists well in the warp sense, much less in the weft sense and it deforms very much in diagonal. To cover a sofa, for example, all pieces of fabric must be cut and sawn in the same sense, while leather allows for much more freedom. Unfortunately the best leather is also the more delicate. Finally, also leather must be fireproof.
17.8. The leather imitation
The leather imitation doesn’t have the scent and preciousness of real leather. Yet there are some imitations that are as soft and pleasing to the touch as real leather. Sometimes they’re also more expensive. These imitations are fit for some uses, like for the ceilings upholstery. They’re produced and sold in rolls, while animal skin has limited dimensions, which means joining several skins to get large pieces. The leather imitation is easily washable: sometimes using it for sofa upholstery would relax the vessel’s owner while kids run around wearing wet bathing suits and handling soft drinks.
17.9. The paint
Please see 8.7. I only wish to add that the deck teak must not be painted. The paint choice follows several criteria. To mention just two, one is the colours: each one of them is internationally indicted by a number called RAL (Rechtsausschuß für Lieferbedingungen). The RAL scale is divided in HR for the matt colours and GL for the shiny ones. There are more than 2,000 colour codes. Another criterion is the “gloss”, which indicates the grade of opacity of a painted surface. A totally opaque surface has value “0”, a perfectly shiny one has the hypothetic value “100”: see figure # 89. It goes without saying that the shinier is the surface, the easier is to spot every flaw.
Very Opaque Gloss value from 1 to 10