CARPENTRY
Introduction: - Carpentry and joinery are common terms used with any class of work with wood. Strictly speaking, carpentry deals with all work of constructional nature as roof, floors partitions of a building, while joinery deals with the making of doors windows, cupboards, dressers stairs and all type of interior fitments of a building.
Carpentry materials
Timber is the basic material used for any class of carpentry work. The timber is classified into two types namely exogenous and endogenous. The exogenous trees grows from internal to external. The endogenous tree grows from the top. The examples for endogenous tree are palm, coconut tree bamboo etc. The term timber is applicable to the trees which provide as with wood. Timbers for commercial purpose are divided into two classes’ namely soft wood and hard wood.
1. Soft wood: - It is obtained from the trees having needle leaves. It is light in weight and light in colour and has strong fibers. The annual rings are visible and have a god tensile strength in axial direction.
2. Hard wood: - It is obtained from the trees having broad leaves. The annual rings are not visible clearly and its fibres are very close, compact. It is heavier than soft wood and difficult to work. It has almost equal strength in radial as well as in the axial direction.
Cross section of a timber:- The cross section of a timber is shown in figure. It has the following parts.
1. Bark: It is the outer most layer of the tree. It protects the cambium layer from insects.
2. Cambium layer: This layer is in between the sap wood and the bark. As time passes, the inner portion is gradually change into sap wood.
3. Sap wood: The food conduction and storage in most trees are only by the outer layer of the wood stem. This is known as the sap wood. Sap wood can be seen just inside the cambium layer for a certain distance towards centre. This part of the wood is not very useful for the engineering works. It is largely used as fuel. It is lighter in colour and is softer.
4. Medullarly Rays: these are rays which run radial from cambium layer towards the pith, crossing the annual ring abnormally.
5. Pith: it is the centre portion of the tree. Pith is very soft portion and varies in size and shapes for different types of trees. It consists of cellular tissues.
6. Annular rings: Trees puts on layers of woo during the growth season each year. These are concentric layers of wood known as growth rings or annual rings.
Defects in Timber:
The common defect in timber is knots. Knots are divided into two groups
1) Dead knots: These are impressions left over by the broken timbers or branches of trees. It the branches are cut or broken before the tree is cut, this type of defects occur.
2) Live Knots: A knot whose fibres are completely intergrown with this type of knots.
Wood seasoning:
The main objective of the process is to reduce the moisture content to the desired extent so as to make the wood suitable for specific uses. The advantages of seasoning is to make the timber hard, durable, shock and stress resistant and to improve its workability.
1. Natural seasoning
It is also known as ‘Air seasoning’. The timber are stacked under a shed so as to be free from sun and rain but are so arranged that the atmospheric air have a free circulation through the stacks. This stacks of timber is allowed to undergo various temperature changes, thus makes the inside moisture to evaporate and thus the timber gets dried. This process takes as much as one to five years. This is the cheapest method, which gives the best seasoned wood.
2. Water seasoning
In this process timbers are fully immersed in the flowing water and are made to remain for about 2 to 3 weeks. The flowing water takes away the sap wood along with it. The timber is then taken out of water and air seasoning is carried out.
3. Artififial seasoning
It is the quickest process of seasoning timber but is equally costly. In this process, tree, timbers are stacked in the same way as in air seasoning in dry oven called kilns. Inside the kilns dry steam at a temperature of 50 -60°C is made to pass through the stack. The process of drying is very slow at the beginning stage and then goes at a faster rate gradually.
4. Chemical seasoning:
In this method the timber is soaked in saturated salt solution and then taken out and seasoned in the ordinary way by keeping in open and dry place. Since the exterior surface of the timber dries in advance of the interior one, the chances of formation of external crack are reduced.
CARPENTRY TOOLS
In order to successfully work with different forms to accurate shapes and dimensions, the wood worker must know the use of a large number of toots.in order to successfully work different forms of accurate shapes and dimensions, the wood worker must know the use of a large number of Carpentry tools are classified into ...
1) Hand tools
2) Machine tools
3.1 Hand tools
Tools which are manipulated by hand are known as hand tools. Hand tools are further classified as given below.
3.1.1 Marking and measuring tools Marking and measuring tools have been developed in order to work truly and accurately. The most common types are as follows.
Rules: Rules of various type and design are used by wood workers for measuring and setting out dimensions.
Straight edge: The straight edge is a machined flat piece of wood or metal having straight and parallel edges. One of the longitudinal edges is generally made leveled. This is used to check the trueness of large surfaces and edges.
Try square: Try square is used for marking and checking angles of 90°
Mitre square: Mitre square is set so that they measure an angle of 45°. Different sizes of mitre square are available.
Bevel squares : It is similar to try square but has a blade which can be set to any angle from 0 to 100°
Marking knife: Marking knife is used for converting the pencil lines into the cut lines.
Gauges: Gauges are used to mark lines parallel to the edge of a piece of wood. It consists of a small stem sliding in a stock. The stem carries on or two steel marking points or a cutting knife. The stock is set to the desired position from the steel point and fixed by the thumb screw.
Mortise gauge:
The mortise gauge has two marking points. One fixed near to the end of the stem and the other attached to a brass sliding bar. These two teeth cuts two parallel lines called mortise lines.
Wing compass: Wing compass are composed of two finally pointed steel legs which are set to the desired position and held by a set screw a quadrent.
Trammel: The trammel is a form of beam compass, with a wooden or metal beam to take a work that is beyond the scope of a compass.
Cutting tools.
Cutting tools includes saws, chisels, gouges planes etc.
Saws:-
The saw is probably the most abused of wood working tools, chiefly because inexperienced users force it too much. While cutting across the grain, a different action is required from the saw teeth than when rapping with the grain. Therefore different types of saws are used as one type cannot do both jobs successfully. Saw is generally specified by the length of its blade.
1. Rip saw:- These saws are used for cutting along the grain in thick wood.
2. Cross cut saw: - Cross cut saw or hand saw are used for cutting across the grain in thick wood. The teeth angle is usually 60 degree and the beveling will be towards the side
3. Tennon or back saw: - This saw is mostly used for cross cutting when finer and more accurate finish is required. The blade being very thin, it is reinforced by a rigid steel back.
4. Coping saw: - This saw has a very narrow blade held rigid in spring metal frame and is used for small radius curves.The cutting action takes place in return stroke.
Compass saw: - The compass saw is used for sawing small curves in confined spaces and has a narrow tapering blade.
5. Pad for key hole saw: - This is the joiners smallest saw about 250 mm long, used for cutting key wholes or the starting of any interior cuts.
Chisels: - Wood chisels most commonly used include firmer chisel either square or bevel edged, paring chisels and mortise chisels. They are usually specified by length and width of the blade.
6. Firmer chisels: - It is the most useful general purpose chisel and may be used for hand pressure or mallet.
Bevel edge firmer chisel: - It is used for more delicate or fine work. They are useful for getting into corners where the ordinary chisel would be clumsy.
7. Paring chisels: - Both firmer and beveled edge chisel when they are made with long and thin blades are known as paring chisel.
This is used for shaping and preparing the surfaces of wood and is manipulated by the hand.
8. Mortise chisel: - The mortise chisel as its name indicates, is used for chopping out mortises. These chisels are designed to withstand heavy work.
9. Gouges: - Gouges are chisels with curved sections and may be either inside(inside gouge) or out side ground. They are used for making curved edges and for curving hollows.
Planes: -
The plane can be likened to the chisel fastened into a block of metal or wood and its blade cuts exactly like a wide chisel. The planes in general use are the jack plane, smoothing plane, box plane and are known as bench planes. Besides these there are other types of plane which are used for special purpose.
1. Jack plane: - This is the commonest and is used for first truing up of a piece of wood. It consists of a block of wood in which the blade is fixed by a wedge. The blade is set at an angle of 45° to the sole. To set this blade a back iron is used.
2. Smoothing plane: - This plane is similar in action to jack plane, except that it is set to cut much thinner shaving after the use of a jack plane. The usual angle of blade is 55° with the sole.
3. Rebate plane: - A rebate plane is to make recess along the edge of wooden piece. It is usually used for positioning the glass in the frame of windows and doors.
4. Spoke shave: - this is a small plane used for cleaning up quick curves. There are two types, one which has a flat sole and for outside curves and the other has a curved sole for inside curves.
Boring tools:-
Boring tools are frequently necessary to make round holes in wood and they are selected according to the type and purpose of the hole. They include bradawl gimlet, braces and drill.
1. Bradawl and Gimlet: These are hand operated tool and used to bore small holes.
2. Drill bit: drills are used to make hole. There are many types of bits available. The most important item used in wood work are shell bit, flat bit, auger bit, twist drill and counter sunk bit.
Striking tools: Striking toolls include hammers and mallets.
1. Hammers: - Most commonly used hammers in wood working are cross peen hammer straight peen hammer ball peen hammer and claw hammers. The warrington hammer is used where the other type of hammer can’t be used such as driving the nail inside a corner of a box etc.
2. Mallet: - It is a wooden headed hammer of round or square cross section. This is used to give light blows to the cutting tools having wooden handle such as chisels and gouges.
Holding tools:-
To enable the wood worker to cut his wood accurately, it must be held properly. For this purpose holding tools are used. There are many types of holding devices are available and can be used according to the nature of the work to be done.
1. Carpenters vice: - It consists of two jaws and out of this one jaw is movable by means of a screw and handle and the other is fixed.
2. Bench stop: - The bench stop is simply a block of wood projecting above the top surface of the work bench. This is used to prevent the wood from moving forward while planning.
3. ‘G’ or ‘C’ clamp: - This clamp consists of a malleable iron frame in the ‘c’ shape and a screw to clamp the work piece on the table. Sash clamp is used to hold the large size work piece.
Miscellaneous tools
1 Rasp and files: - These are used for cleaning up some curved surfaces.
2 Glass paper: - It is used for the smoothing the surface after working with planner and chisels. Concave shapes can only be finished only by using sand paper/glass paper.
3 Oil stone: - Oil stones are used for final sharpening of chisels and gouges. This may be either natural or artificial stone made from carborundum (Aluminum oxide).
4 Pincer: - is mainly used for pulling nails and pins.
5 Screw drivers: - Screw drivers are used for screwing or unscrewing screws used in wood work. These may be obtained in various sizes.
Machine tools:-
1.Band saw: is used to cut the wood in Longitudinal direction
2.circular saw: is used to cut the wood across the wood
3.Planer is used to plane the wood
4.wood working lathe is used for turning the wood to make the desired design
5.Router : for making groves and steps
---------------------------------------------------------------------------------------------END OF NOTES ---------------------------------------------------------------------------------------------------------------
Carpentry materials
Timber is the basic material used for any class of carpentry work. The timber is classified into two types namely exogenous and endogenous. The exogenous trees grows from internal to external. The endogenous tree grows from the top. The examples for endogenous tree are palm, coconut tree bamboo etc. The term timber is applicable to the trees which provide as with wood. Timbers for commercial purpose are divided into two classes’ namely soft wood and hard wood.
1. Soft wood: - It is obtained from the trees having needle leaves. It is light in weight and light in colour and has strong fibers. The annual rings are visible and have a god tensile strength in axial direction.
2. Hard wood: - It is obtained from the trees having broad leaves. The annual rings are not visible clearly and its fibres are very close, compact. It is heavier than soft wood and difficult to work. It has almost equal strength in radial as well as in the axial direction.
Cross section of a timber:- The cross section of a timber is shown in figure. It has the following parts.
1. Bark: It is the outer most layer of the tree. It protects the cambium layer from insects.
2. Cambium layer: This layer is in between the sap wood and the bark. As time passes, the inner portion is gradually change into sap wood.
3. Sap wood: The food conduction and storage in most trees are only by the outer layer of the wood stem. This is known as the sap wood. Sap wood can be seen just inside the cambium layer for a certain distance towards centre. This part of the wood is not very useful for the engineering works. It is largely used as fuel. It is lighter in colour and is softer.
4. Medullarly Rays: these are rays which run radial from cambium layer towards the pith, crossing the annual ring abnormally.
5. Pith: it is the centre portion of the tree. Pith is very soft portion and varies in size and shapes for different types of trees. It consists of cellular tissues.
6. Annular rings: Trees puts on layers of woo during the growth season each year. These are concentric layers of wood known as growth rings or annual rings.
Defects in Timber:
The common defect in timber is knots. Knots are divided into two groups
1) Dead knots: These are impressions left over by the broken timbers or branches of trees. It the branches are cut or broken before the tree is cut, this type of defects occur.
2) Live Knots: A knot whose fibres are completely intergrown with this type of knots.
Wood seasoning:
The main objective of the process is to reduce the moisture content to the desired extent so as to make the wood suitable for specific uses. The advantages of seasoning is to make the timber hard, durable, shock and stress resistant and to improve its workability.
1. Natural seasoning
It is also known as ‘Air seasoning’. The timber are stacked under a shed so as to be free from sun and rain but are so arranged that the atmospheric air have a free circulation through the stacks. This stacks of timber is allowed to undergo various temperature changes, thus makes the inside moisture to evaporate and thus the timber gets dried. This process takes as much as one to five years. This is the cheapest method, which gives the best seasoned wood.
2. Water seasoning
In this process timbers are fully immersed in the flowing water and are made to remain for about 2 to 3 weeks. The flowing water takes away the sap wood along with it. The timber is then taken out of water and air seasoning is carried out.
3. Artififial seasoning
It is the quickest process of seasoning timber but is equally costly. In this process, tree, timbers are stacked in the same way as in air seasoning in dry oven called kilns. Inside the kilns dry steam at a temperature of 50 -60°C is made to pass through the stack. The process of drying is very slow at the beginning stage and then goes at a faster rate gradually.
4. Chemical seasoning:
In this method the timber is soaked in saturated salt solution and then taken out and seasoned in the ordinary way by keeping in open and dry place. Since the exterior surface of the timber dries in advance of the interior one, the chances of formation of external crack are reduced.
CARPENTRY TOOLS
In order to successfully work with different forms to accurate shapes and dimensions, the wood worker must know the use of a large number of toots.in order to successfully work different forms of accurate shapes and dimensions, the wood worker must know the use of a large number of Carpentry tools are classified into ...
1) Hand tools
2) Machine tools
3.1 Hand tools
Tools which are manipulated by hand are known as hand tools. Hand tools are further classified as given below.
3.1.1 Marking and measuring tools Marking and measuring tools have been developed in order to work truly and accurately. The most common types are as follows.
Rules: Rules of various type and design are used by wood workers for measuring and setting out dimensions.
Straight edge: The straight edge is a machined flat piece of wood or metal having straight and parallel edges. One of the longitudinal edges is generally made leveled. This is used to check the trueness of large surfaces and edges.
Try square: Try square is used for marking and checking angles of 90°
Mitre square: Mitre square is set so that they measure an angle of 45°. Different sizes of mitre square are available.
Bevel squares : It is similar to try square but has a blade which can be set to any angle from 0 to 100°
Marking knife: Marking knife is used for converting the pencil lines into the cut lines.
Gauges: Gauges are used to mark lines parallel to the edge of a piece of wood. It consists of a small stem sliding in a stock. The stem carries on or two steel marking points or a cutting knife. The stock is set to the desired position from the steel point and fixed by the thumb screw.
Mortise gauge:
The mortise gauge has two marking points. One fixed near to the end of the stem and the other attached to a brass sliding bar. These two teeth cuts two parallel lines called mortise lines.
Wing compass: Wing compass are composed of two finally pointed steel legs which are set to the desired position and held by a set screw a quadrent.
Trammel: The trammel is a form of beam compass, with a wooden or metal beam to take a work that is beyond the scope of a compass.
Cutting tools.
Cutting tools includes saws, chisels, gouges planes etc.
Saws:-
The saw is probably the most abused of wood working tools, chiefly because inexperienced users force it too much. While cutting across the grain, a different action is required from the saw teeth than when rapping with the grain. Therefore different types of saws are used as one type cannot do both jobs successfully. Saw is generally specified by the length of its blade.
1. Rip saw:- These saws are used for cutting along the grain in thick wood.
2. Cross cut saw: - Cross cut saw or hand saw are used for cutting across the grain in thick wood. The teeth angle is usually 60 degree and the beveling will be towards the side
3. Tennon or back saw: - This saw is mostly used for cross cutting when finer and more accurate finish is required. The blade being very thin, it is reinforced by a rigid steel back.
4. Coping saw: - This saw has a very narrow blade held rigid in spring metal frame and is used for small radius curves.The cutting action takes place in return stroke.
Compass saw: - The compass saw is used for sawing small curves in confined spaces and has a narrow tapering blade.
5. Pad for key hole saw: - This is the joiners smallest saw about 250 mm long, used for cutting key wholes or the starting of any interior cuts.
Chisels: - Wood chisels most commonly used include firmer chisel either square or bevel edged, paring chisels and mortise chisels. They are usually specified by length and width of the blade.
6. Firmer chisels: - It is the most useful general purpose chisel and may be used for hand pressure or mallet.
Bevel edge firmer chisel: - It is used for more delicate or fine work. They are useful for getting into corners where the ordinary chisel would be clumsy.
7. Paring chisels: - Both firmer and beveled edge chisel when they are made with long and thin blades are known as paring chisel.
This is used for shaping and preparing the surfaces of wood and is manipulated by the hand.
8. Mortise chisel: - The mortise chisel as its name indicates, is used for chopping out mortises. These chisels are designed to withstand heavy work.
9. Gouges: - Gouges are chisels with curved sections and may be either inside(inside gouge) or out side ground. They are used for making curved edges and for curving hollows.
Planes: -
The plane can be likened to the chisel fastened into a block of metal or wood and its blade cuts exactly like a wide chisel. The planes in general use are the jack plane, smoothing plane, box plane and are known as bench planes. Besides these there are other types of plane which are used for special purpose.
1. Jack plane: - This is the commonest and is used for first truing up of a piece of wood. It consists of a block of wood in which the blade is fixed by a wedge. The blade is set at an angle of 45° to the sole. To set this blade a back iron is used.
2. Smoothing plane: - This plane is similar in action to jack plane, except that it is set to cut much thinner shaving after the use of a jack plane. The usual angle of blade is 55° with the sole.
3. Rebate plane: - A rebate plane is to make recess along the edge of wooden piece. It is usually used for positioning the glass in the frame of windows and doors.
4. Spoke shave: - this is a small plane used for cleaning up quick curves. There are two types, one which has a flat sole and for outside curves and the other has a curved sole for inside curves.
Boring tools:-
Boring tools are frequently necessary to make round holes in wood and they are selected according to the type and purpose of the hole. They include bradawl gimlet, braces and drill.
1. Bradawl and Gimlet: These are hand operated tool and used to bore small holes.
2. Drill bit: drills are used to make hole. There are many types of bits available. The most important item used in wood work are shell bit, flat bit, auger bit, twist drill and counter sunk bit.
Striking tools: Striking toolls include hammers and mallets.
1. Hammers: - Most commonly used hammers in wood working are cross peen hammer straight peen hammer ball peen hammer and claw hammers. The warrington hammer is used where the other type of hammer can’t be used such as driving the nail inside a corner of a box etc.
2. Mallet: - It is a wooden headed hammer of round or square cross section. This is used to give light blows to the cutting tools having wooden handle such as chisels and gouges.
Holding tools:-
To enable the wood worker to cut his wood accurately, it must be held properly. For this purpose holding tools are used. There are many types of holding devices are available and can be used according to the nature of the work to be done.
1. Carpenters vice: - It consists of two jaws and out of this one jaw is movable by means of a screw and handle and the other is fixed.
2. Bench stop: - The bench stop is simply a block of wood projecting above the top surface of the work bench. This is used to prevent the wood from moving forward while planning.
3. ‘G’ or ‘C’ clamp: - This clamp consists of a malleable iron frame in the ‘c’ shape and a screw to clamp the work piece on the table. Sash clamp is used to hold the large size work piece.
Miscellaneous tools
1 Rasp and files: - These are used for cleaning up some curved surfaces.
2 Glass paper: - It is used for the smoothing the surface after working with planner and chisels. Concave shapes can only be finished only by using sand paper/glass paper.
3 Oil stone: - Oil stones are used for final sharpening of chisels and gouges. This may be either natural or artificial stone made from carborundum (Aluminum oxide).
4 Pincer: - is mainly used for pulling nails and pins.
5 Screw drivers: - Screw drivers are used for screwing or unscrewing screws used in wood work. These may be obtained in various sizes.
Machine tools:-
1.Band saw: is used to cut the wood in Longitudinal direction
2.circular saw: is used to cut the wood across the wood
3.Planer is used to plane the wood
4.wood working lathe is used for turning the wood to make the desired design
5.Router : for making groves and steps
---------------------------------------------------------------------------------------------END OF NOTES ---------------------------------------------------------------------------------------------------------------