The Language of Wood
Here are some of the terms commonly used to distinguish between the unique characteristics you'll find in different woods.
|Hardwood||Wood cut from broad-leaved, mostly deciduous, trees.|
|Grain||The general direction of the fibers in wood that gives it a unique pattern.|
|End Grain||The surface of wood exposed after cutting across the fibers.|
|Sapwood||The new wood of the tree that helps carry sap and stores food for tree growth.|
|Heartwood||The mature wood that forms the spine of the tree. Usually harder than sapwood.|
|Mineral Streak||A dark brown to black area where minerals have been absorbed into the tree.|
|Birdpeck||Minute, pitted areas in wood.|
|Pitchpocket||An opening in the wood fiber that has held the resinous material "pitch."|
|Burl||A knot in wood that gives the wood fibers a beautiful peacock-tail pattern.|
|Medullary Ray||A pattern of light that runs across the grain, causing "ray-fleck" or "splash figures."|
|Movement||The shrinkage and expansion of wood as it gives off and absorbs moisture.|
Storage and Job Conditions
Store woodwork in a dry, ventilated space, protected from weather, dirt and damage. When storing mouldings for extended periods of time or in areas of higher than recommended humidity, seal the ends of all pieces as soon as possible.
Mouldings should be at optimum moisture content at the time of installation. Maintain installation areas in the relative humidity range required for the Optimum Moisture Content of wood. Material should be allowed to acclimate to installation area conditions prior to installation.
The Natural Characteristics of Wood
Unlike man-made materials that can be manufactured to consistent specifications, wood is a product of nature. Its natural imperfections are part of its appeal and character. Every piece of woodeven within the same treeis slightly different in color, texture and grain from every other piece. How wood looks and feels is dictated by a number of factors, including climate, soil nutrients, growing season, season of harvest and age at harvest.
Let's look at some natural characteristics of hardwoods that can affect its appearance and, ultimately, the look of your moulding.
|Grain||More than anything, grain gives wood its artistry. Depending on how it grows, a tree can produce wood with straight grain, cross grain, spiral grain, interlocking grain or even wavy or curly grain. Each type of grain causes light to play off of it differently.
Grain is also used to describe how the wood is cut or worked. Sawing and planing can be done "against the grain," "with the grain" or "across the grain"with each method having a different effect on how the wood accepts stain.
|Natural color||Although we're used to seeing it stained or painted, wood in its natural state appears as shades of white, green, red and black. The natural color of unfinished wood is an important factor in determining its finished color. Light base and transparent stains allow these color variations to show through, while darker stains will be affected by the natural color of the wood.
Due to variation in grain, texture and natural color, a stained finish may vary slightly from one area to another. The type of lighting and the angle of the light on wood can also appear to change the color of the finish. Depending on the species, cut and type of finish, all wood also darkens to some degree as it ages. Conditions in the home or office environmentultraviolet light, cleaning chemicals, smoke, etc.can also affect color.
|Mineral streaks||A dark brown to black area in the wood where the tree absorbed nutrients. Since the number of mineral streaks varies from board to board, you may notice differences in your moulding. These streaks are especially evident in light wood such as maple and in light stains or natural finishes when no stain is applied.|
|Movement||This refers to the expansion and contraction of wood as it absorbs and gives off moisture. Some hardwoods, such as cherry and maple, are more sensitive to changes in temperature.|