1. 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

2. 4.1 Wood properties and constitution
Lignin: it makes wood harder and more rigid, it’s like glue that holds the cellulose together. 3

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

5. 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

6. 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

7. 2º Delimbing: Removing branches from the trunks.
4.2 Wood extraction and processing
2º Delimbing: Removing branches from the trunks. 12

8. 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

9. 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

10. 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

11. 6º Drying: Removing moisture to prevent deformation.
4.2 Wood extraction and processing
6º Drying: Removing moisture to prevent deformation. 16

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. 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

19. 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

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

21. 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

22. 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

23. 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

24. 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

25. 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

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

27. 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

28. 3.6 Wood Tools
2 To hold
We have to be careful before cutting or manipulating any object. We have to immobilize it. 35

29. 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

30. 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

31. 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

32. 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

33. 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

34. 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

35. 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

36. 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

37. 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

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

39. 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

40. 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

41. 6 To join 3.6 Wood Tools We can also use screws and screwdrivers48

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

43. 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

44. 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

45. 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