Materials can be selected based upon their working properties. It is important to know and understand which materials can be used for a specific purpose:
When selecting a timber-based material, there are many different types to choose from. Hardwood and softwood are types of timber that come from many different trees. Manufactured boards such as medium-density fibreboard MDF are man-made from recycled material and other boards such as plywood are man-made from layers of wood. Manufactured boards have a number of advantages, including:
Plywood is made by gluing at least three layers of sheet timber together at right angles to each other - this is called laminating. Plywood is considered to be a strong board as the grain of the timber sheets are glued together in different directions.
Blockboard has a sandwich construction where the core is made from strips of softwood and the two other surfaces areas are made from hardwood veneer to produce a relatively lightweight manufactured board that is strong and durable.
Each type of timber or board will function differently and can therefore be used in different environments. Some timbers are hard and very dense, whereas some are lighter and softer to cut and work with. They are categorised as hardwoods or softwoods and this affects their properties, aesthetics and potential uses.
Aesthetics relate to the way a material looks, and each example of timber has a different pattern on the grain and texture. The way a timber looks can be altered through several methods:
Quite often MDF is laminated with a single sheet of a hardwood veneer to give the impression that solid hardwood has been used to make a product, but at a fraction of the cost.
When a tree is chopped down for timber, there is a cost to the environment. Trees are vital for our survival as they absorb carbon dioxide (CO2). Although more than one tree can be planted for each tree that is chopped down, older trees often absorb more carbon dioxide and provide more of a habitat for wildlife due to their size.
The availability of a material is an important consideration too. Some softwoods are readily available due to the fast-growing nature of the tree. Hardwood, on the other hand, grows considerably slower and is therefore much more expensive.
Material costs are an important factor when selecting material. It is often possible that more than one material is suitable for a job, and it may be the cost that determines which one is used.
Manufactured boards vary in price depending on where they are bought and how many are bought at once. Some timber is sold at a price calculated by volume. The price per metre cubed (m3) is the method of working out the value. If the price per m3 is known, then the calculation to work out the cost starts with working out the volume of timber that is needed.
A piece of oak costs £1,700 per m3 and the piece to be valued is 1,000 mm × 50 mm × 250 mm. Calculate the price.
Convert to metres (m):
1,000 mm = 1 m
50 mm = 0.05 m
250 mm = 0.25 m
Work out the volume needed (m3):
Volume = 1 m × 0.05 m × 0.25 m
= 0.0125 m3
Work out total cost (£):
Total cost = volume in m3 × cost for 1 m3
= 0.0125 × 1,700 = 21.25
Total cost = £21.25
A plank of ash will be used in the design of a guitar body. It costs £1,850.00 per m3 and the neck design requires 650 mm × 60 mm × 55 mm.
Calculate the cost of the neck section.
Volume = 0.65 m × 0.06 m × 0.055 m = 0.002 m3
Total cost = 0.002 × 1,850 = £3.96