Unit 4. The materials. Wood What are we going to see in this unit? 4.1 Wood properties and constitution 4.2 Wood extraction and processing 4.3 Wood classification 4.4 Wood derivatives 4.5 Wood tools 4.6 Working with wood 1

4.1 Wood properties and constitution Lignin: it makes wood harder and more rigid, it’s like glue that holds the cellulose together. 3

4.1 Wood properties and constitution Cambium: Thin transparent layer that develops new wood. Bark: This last layer protects the tree from insects and disease. 5

4.1 Wood properties and constitution Sonority: is the way it transmits the sound

4.2 Wood extraction and processing If we want to obtain a new wood board, we need to get wood from the environment and process it. 10

1º Felling: Cutting the trunk down with power saws. 4.2 Wood extraction and processing 1º Felling: Cutting the trunk down with power saws. 11

2º Delimbing: Removing branches from the trunks. 4.2 Wood extraction and processing 2º Delimbing: Removing branches from the trunks. 12

Truck 3º Transportation: 4.2 Wood extraction and processing 3º Transportation: The wood is transported by truck, train or, in the past, by floating the trunks downstream. Truck 13

bark 4º Debarking: we remove the bark with special machines. 4.2 Wood extraction and processing 4º Debarking: we remove the bark with special machines. bark 14

Boards 5º Sawing trunks into boards: 4.2 Wood extraction and processing 5º Sawing trunks into boards: The trunks are cut to minimize defects, so we get good quality wood Boards 15

6º Drying: Removing moisture to prevent deformation. 4.2 Wood extraction and processing 6º Drying: Removing moisture to prevent deformation. 16

7º Sanding: Finally, any imperfections are removed from the board. 4.2 Wood extraction and processing 7º Sanding: Finally, any imperfections are removed from the board. 17

Soft wood Hard wood 4.3 Wood classification The type of wood depends on the type of tree it comes from. Classification: Soft wood Hard wood 18

4.3 Wood classification Soft wood: usually comes from resinous trees with perennial leaves. The wood has a clear color and it is easy to manipulate. For example, pine and fir trees. fir pine 19

4.3 Wood classification Hard wood: comes from trees with deciduous leaves. The wood is dark in colour and difficult to manipulate. For example, oak and ebony. oak ebony 20

We have two main groups of wood derivatives: We can obtain different materials from wood that improve the original properties. We have two main groups of wood derivatives: Engineered wood Paper 22

4.4 Wood derivatives Engineered wood examples: Plywood (contraplacat): several sheets of wood Clipboard (conglomerat): thin slices of wood glued and pressed. The thinner the chips, the more resistant the board. MD (dm) (medium density) board: really small slices of wood that create a strongly engineered type of wood. 24

4.4 Wood derivatives Engineered wood examples: Plywood (contraplacat): several sheets of wood Clipboard (conglomerat): thin slices of wood glued and pressed. The thinner the chips, the more resistant the board. MD (dm) (medium density) board: really small slices of wood that create a strongly engineered type of wood. 25

4.4 Wood derivatives We obtain Paper from wood after several steps of an industrial process 1.The wood is chipped 2.Pulp is obtained 4 It’s pressed and dried 3.The pulp is washed

Working with wood In our projects the more suitable woods are: Balsa/Pine wood (llistons de fusta) DM or Plywood 27

Working with wood We are going to make objects with wood, but first we have to know how to…: Measure and mark Hold Cut and saw Drill Refine Join Refinish 28

3.6 Wood Tools 1.To measure and mark The first thing we have to do is to measure and mark the pieces of the object. 29

3.6 Wood Tools 1.To measure and mark We have to be careful when we measure, because one mistake can ruin our project. 30

We have to make good use of the materials 3.6 Wood Tools 1.To measure and mark We have to make good use of the materials 31

Tape measure Metal ruler Carpenter ruler 3.6 Wood Tools 1.To measure and mark Tape measure Metal ruler Metal square: it’s used to mark 90º degrees Carpenter ruler 32

Metal square: it’s used to mark 90º degrees 3.6 Wood Tools Metal square: it’s used to mark 90º degrees 33

Metal compass: it’s used to transport measures 3.6 Wood Tools 1.To measure and mark Metal compass: it’s used to transport measures Carpenter pencil: you can sharpen it with a knife Punch: it’s use to make holes 34

3.6 Wood Tools 2 To hold We have to be careful before cutting or manipulating any object. We have to immobilize it. 35

2 To hold 3.6 Wood Tools G cramp: it holds the object to the table Vice: It’s used to hold objects in place 36

Once we have marked and held our material, we can cut it with a saw. 3.6 Wood Tools 3 To cut and saw Once we have marked and held our material, we can cut it with a saw. We have different saws to make different cuts 37

3.6 Wood Tools 3 To cut and saw If we want to cut wood we need a big set saw and if we want to cut metal we need a small set saw Big set small set 38

3 To cut and saw The coping saw: it’s used to saw thin 3.6 Wood Tools 3 To cut and saw The coping saw: it’s used to saw thin boards and to make difficult cuts 39

The crosscut handsaw: it’s used to saw thick 3.6 Wood Tools 3 To cut and saw The crosscut handsaw: it’s used to saw thick boards. It’s flexible so it can resist the efforts 40

The backsaw: it has a brace that helps to make straight cuts 3.6 Wood Tools 3 To cut and saw The backsaw: it has a brace that helps to make straight cuts Brace 41

The hack saw: This saw is used to cut metal. It has a small set 3.6 Wood Tools 3 To cut and saw The hack saw: This saw is used to cut metal. It has a small set Big set small set 42

3.6 Wood Tools 4 To drill When we want to make a hole we can use a wood screw or a drill (manual or electric). 43

3.6 Wood Tools 5 To refine When we saw the material we have to refine the cut, in order to obtain straight sides 44

The refining tools are glasspaper and files 3.6 Wood Tools 5 To refine The refining tools are glasspaper and files 45

We use files to refine metal and the rasp to refine wood 3.6 Wood Tools 5 To refine We use files to refine metal and the rasp to refine wood striations File=> Metal Teeth Rasp => Wood 46

3.6 Wood Tools 6 To join When we want to join together two boards or any pieces of wood we can hammer a nail into the wood Hammers Nails 47

6 To join 3.6 Wood Tools We can also use screws and screwdrivers 48

Each screw has a special head 3.6 Wood Tools 6 To join Each screw has a special head 49

We can put together wood using glue. It’s cheap and easy 3.6 Wood Tools 6 To join We can put together wood using glue. It’s cheap and easy 50

Finally, we can also use a hot glue gun. 3.6 Wood Tools 6 To join Finally, we can also use a hot glue gun. 51

3.6 Wood Tools h. Refinishing: Refinishing protects wood and improves its appearance. The wood has to be dry, clean and soft. Dying. Water and alcohol Varnishing Wax finishing Oil finishing Painting 52