Working with woods
Wood is the only natural boat building material used today, and although it generally requires more maintenance than the more common glass fibre vessels, a well cared for boat, built of wood, will always attract admiring glances when she sails into view.
The fibrous nature of timber means that it has a tendency to absorb moisture from the atmosphere, and swell and contract to varying degrees depending on the type of construction. For a varnish or paint coating to stay intact it will need to be quite flexible in nature. The moisture content in wood can allow the growth of fungal spores, which leads to rotting and decay. Wood can also be subject to attack by marine borers, which eat the wood fibres. Wood therefore needs to be protected by good quality preservatives and coatings. Many different woods can be used, which can differ immensely.
Hardwoods
Hardwood comes from slow growing deciduous trees. They have a tighter grain than soft woods. This tight grain has good strength characteristics across the timber as well as along its length, making it particularly suitable for decorative application, as well as boat building.
Mahogany
Mahogany will last for many years in a marine environment with little protection as the seawater has an antiseptic quality. The same is not true with regard to fresh water, which will lead to rot and decay if allowed to permeate the wood fibres. Mahogany should, therefore, be protected from freshwater at all times and wherever possible washed down with seawater.
Teak and Iroko
Teak and iroko are particularly oily timbers with a natural resistance to rot and decay. Additionally they contain silica, which gives them hard-wearing characteristics.
Oak
Ferrous metals, such as steel and iron, react badly with oak, due to the tannin in the fibres. This will cause dark staining and even chemical attack on the metal by the tannic acid, which is formed.
Softwoods
The grain in these woods is long, straight and generally wider spaced than hardwoods as these trees grow faster. This means that their strength is mostly along their length so they are used in such applications as masts and spars, tillers, rubbing strakes, oars and planked hulls.