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S E L E C T I X G AND B VV I N G SUITABLE W O O D

Fic 2.22 The brown lines on the near corner of tbis piece of linie are shakes which were repaired by the growing tree.

Fig 2.23 Padaukfreshly cut across the endgmin, but with varying degrees of brown where it bas beeti exposed for different periods.

the chisels buc are plcasant to carvc. Some are so hard, like African blackwood {Dalbergia melanoxylon), lignum vitae (Guaiacum officinale) and cbony (Diospyros ebenum), chat they need very thick cdges to your chisels, bur have their reward in the colour or figurÄ™ and their durability.

Changes to Colour of Wood on Exposure to Light and Air

Woods like laburnum, mulberry (Morus spp.)_y padauk (Pterocarpus spp) (Fig 2.23) and tulip tree dramatically change colour on expo$ure to light and oxygen. UltravioIet light inhibitors oniy delay the change from bright colour to drabness. Purpleheart (Peltogyne spp.), on the othcr hand, is a pale pink on first being cut but quickly goes a rich purple. The usual rule is that light woods go dark and dark woods lighten on exposure to light.

The Right Timber for the Job

In choosing che right timber for a carving you have to consider colour, figurÄ™, ease of working, strength, durability, expcnse and availability in the requircd size. A carving with fine detail will not show as well in a dark as in a light wood, and a strong figurÄ™ will camouflage detail. Dark and highly figured woods arc best suited to simple forms with strong shadows in them. We all like a wood that is casy to work but sometimes this comes with loss of strength in the wood, or a too marked or a too bland figurÄ™. Sometimes, however, Jack of availabilin- may force you to use somerhing difficult like ycw, and you will find that the colour and muted figurÄ™ amply repay the cxtra effort.

Durability

Durability is a main consideration for oucdoor work, particularly where water is likely to build up, as in ground contact. Light-coloured timbers may be safc for oniy a few months. English oak, ycw and ucile can survive up to 25 years, and teak and iroko may last even longcr. The durability of most timbers is recorded in various refcrcnce books. Durability can be prolonged by rhorough treatment with a preservative.

Preservatives

Modern prcservatives can reducc the risk of rot but are expensive, except for creosote which has other disadvantages such as its dark colour,

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