Working with coconut is generally the same as any other wood but there are a few differences which are worth understanding.
A demonstration of this is the steps cut into younger palms by the Toddy drink croppers. These steps will remain unchanged for the lifespan of the palm.
Coconut wood is cut from the bottom of the stem. The wood gradually lessens in density higher up and the moisture content rises until it reaches the edible palm heart which is the growing tip of the palm.
Top section - biomass fuel
<200 kg per cubic metre
Middle section - biomass fuel
200 - 400 kg per cubic metre
Bottom section - useful timber
400 - 1000 kg per cubic metre
Similarly, because the palm is a monocotyledon, the growth is up the centre and the older wood is compressed to the outside and therefore denser. The trunk, once formed does not increase in diameter with age. If the trunk is damaged is does not 'repair' itself as is the case with a dicotyledon. A monocotyledon grows from the top only, there are no branches and no knots.
There is no distinct line between the different densities; the changes are gradual throughout the stem. For this reason grading is of critical importance with coconut timber. At the sawmill we only saw the lower logs which are suitable for timber, the rest is biomass fuel destined for the power station. We grade the timber into two basic categories: the outer hardwood and the inner core timber. Each of these grades have quite different properties and can be used for different applications. An added advantage of the nature of coconut palms is that, within these grade selections, there are smaller variations of colour, grain and shade which enables a wider range of textural selection.
Careful plank selection is an important necessity when working with coconut wood since every plank is different. These differences can be disguised or highlighted depending on your preference.
Coconut timber has no annual rings; the vascular fibres within the cellulose structure grow continuously up the centre of the stem . These fibres are denser on the outside of the stem (the hardwood) and tend to rotate slightly round the stem as they go upwards. For this reason coconut wood cut up to 1" thickness has a tendency to twist. Coconut wood must be stacked correctly with a spacer in between each layer at each end of the plank and one in the middle. The stacks should be orientated to facilitate ventilation through the stack.
Your designs should be engineered to take twisting into consideration. 1" planks should be anchored at the ends.
You will notice that all of our wood, particularly the thicker cut planks, are slightly denser on one side than the other. Keep the denser side to the outside on display.
Working with coconut wood is not much different to other timbers. It has a high silica content and is quite abrasive, we recommend tungsten tipped blades if you have them available. Planing is generally with the grain with the fibres rising away from you. Sanding should be across the grain.
Coconut wood can be jointed in the same manner as other woods.
Hardwood is much dryer in the log than core timber. We air-dry it all for a minimum of two months before it is sold and the equilibrium moisture content comes down to about 17%mc in both grades after that period. We have noticed no great shrinkage or movement in furniture made from air-dried timber which is kept in the shade in the ambient African atmosphere. As with all timbers we would recommend that furniture intended for an unnatural atmosphere is made from timber which is first kiln dried to the appropriate moisture content. This is in respect of timber destined for air-conditioned environments and particularly centrally heated environments.
As with all woods coconut will deteriorate quicker in the harsh African sunlight. If you wish to use it out doors please expect some shrinkage, movement and bleaching. Outdoor timber especially core timber should be protected from rain and sealed with varnish or similar lacquer..
Longitudinally coconut wood has good strength and elasticity but it is quite brittle across the grain. With hardwood we recommend that nail holes are pre-drilled. Core timber is a little softer so banging nails into it is not a problem.
Coconut finishes well and accepts polishes, waxes, varnishes and lacquers much the same as other timbers. For a natural finish we prefer a natural polish (3 parts virgin coconut oil : 1 part beeswax). This polish should be applied in several coats, sanding between each coat. For a more robust finish we use an egg shell, two part varnish. The core timber is more absorbent than the hardwood and requires more coats.
1" to 2" hardwood can be used for furniture, window and door frames.
1" to 2" core timber is cheaper and is generally used for panelling or mass production furniture such as school desks.
Core timber posts cut 4"x 4",
5"x 5 " or 6"x 6" are turned on a lathe into table legs, bed posts or can be used for interesting furniture designs.
