Mindmap of Specialist content (TIMBERS)
Wood types (hard, soft manufactured) with examples and their properties
Wood sources (where they are from), costings of wood, with the element of social and ethical factors
what feeling is and how wood is dried
Stock forms
timber provenance
Types of faults in timbers
Joining methods
and if you get time woodworking tools and use
hard wood
Oak.
Ash.
Walnut.
Maple.
Beech
soft wood
Pine.
Redwood.
Larch.
Fir.
Cedar.
manufactured boards
plywood
MDF
chip board
hard board
veneer
pine
Wood Type: Softwood.
Durability: Slightly durable.
Treatability: Extremely difficult, Easy (Sapwood)
Moisture Movement: Medium.
Density (mean, Kg/m³): 670 (Density can vary by 20% or more)
Texture: Medium.
Availability: Readily available at timber merchant.
Price: Medium.
redwood
Wood Type: Softwood.
Durability: Slightly durable.
Treatability: Extremely difficult, Easy (Sapwood)
Moisture Movement: Medium.
Density (mean, Kg/m³): 510.
Texture: Medium.
Availability: Readily available at timber merchant.
Price: Low.
larch
Wood Type: Softwood.
Durability: Slightly durable, Moderately durable.
Treatability: Extremely difficult, Moderately easy (Sapwood - Larch sapwood treatability may vary)
Moisture Movement: Small.
Density (mean, Kg/m³): 550.
Texture: Fine.
Availability: Readily available at timber merchant.
Price: Low.
larch
Wood Type: Softwood.
Durability: Moderately durable, Slightly durable (Homegrown timber)
Treatability: Extremely difficult, Difficult (Sapwood)
Moisture Movement: Small.
Density (mean, Kg/m³): 530.
Texture: Medium.
Availability: Readily available at timber merchant.
Price: Medium.
cedar
Wood Type: Softwood.
Durability: Durable.
Treatability: DIfficult.
Moisture Movement: Medium.
Density (mean, Kg/m³): 580.
Texture: Medium to fine, straight grained.
Availability: Limited availability at specialist timber merchant.
Price: Low.
plywood
High Strength and Dimensional Stability. Plywood derives its structural strength from the timber from which it is manufactured.
High Impact Resistance.
Panel Shear or Braced Panels Shear.
Water and Chemical Resistance.
Flexibility or Bendability.
Fire Resistance.
Sound and Thermal Insulation.
MDF
Internal bond strength.
Modulus of rupture.
Modulus of elasticity.
Thickness.
Elasticity.
Water absorption.
Swelling.
The panel has a dark brown colouring. Its properties can be influenced through the addition of additional bonding agents. Hardboards principle advantages are its stable form, light weight, resilience and low cost. Hardboard is also available with film coatings e.g. in white or with wood patterning.
Because of its low cost, chipboard is commonly used to build low-cost indoor furniture, especially the kind shipped in a flat-pack. High-density chipboard is rigid, durable, heavy, and even flame-retardant, making it a useful, yet inexpensive material.
veneer
Types of wood.
Growth features.
Color of wood.
Structure of wood.
Sustainability.
Fire safety.
Sound insulation.
Moisture resistance.
All oak species are strong, hard, heavy and dense with very close grain and, due to their high tannin content, they are very resistant to insect and fungal infestations. Uses: Oak is commonly used for furniture, joinery, flooring, panelling, decking and veneers.
ash
Common Name(s): White Ash, American White Ash.
Distribution: Eastern North America.
Tree Size: 65-100 ft (20-30 m) tall, 2-5 ft (.6-1.5 m) trunk diameter.
Janka Hardness: 1,320 lbf (5,870 N)
Modulus of Rupture: 15,000 lbf/in2 (103.5 MPa)
Crushing Strength: 7,410 lbf/in2 (51.1 MPa)
Walnut wood is hard, heavy, and resilient, capable of resisting warping and suffering very little shrinkage. The grain is irregular but typically straight with a medium texture. The endgrain is semi-porous with distinct growth rings. Although susceptible to insects, English Walnut is quite resistant to decay
mayple
Wood Type: Hardwood.
Durability: Slightly durable.
Treatability: Difficult.
Moisture Movement: Medium.
Abrasions: Very good.
Density (mean, Kg/m³): 740.
Texture: Fine.
Availability: Available at specialist timber merchant.
beach
Wood Type: Hardwood.
Durability: Not durable.
Treatability: Easy.
Moisture Movement: Large.
Density (mean, Kg/m³): 720.
Texture: Fine.
Availability: Readily available at timber merchant.
Price: Low.
Types of Defects in Timber as a Construction Material
Natural forces
Fungi
During Seasoning
During conversion
Insects
Defects in timber due to Natural Forces
Wind cracks
Shakes
Twisted fibers
Upsets
Rind galls
Burls
Water stain
Chemical stain
Deadwood
Knots
Coarse grain
Foxiness
Druxiness
Callus
Shakes in Timber
Shakes are nothing but cracks which separate the wood fibers partly or completely. Different shakes are formed in different conditions as follows:
Cup shakes are formed due to the non-uniform growth of a tree or excessive bending by cyclones or winds. In this case, the shakes develop between annual rings and separate them partly.
Heart shakes, the other type of shakes which develop in maturity approaching trees whose inner part is under shrinkage. The shake spread from pith to sapwood following the directions of medullary rays.
Ring shakes are similar to cup shakes, but they completely separate the annual rings.
Star shakes are formed due to extreme heat or severe frost action. They develop wider cracks on the outside of timber from bark to the sapwood.
Radial shakes are developed radially from pith to the bark.
defects in wood dew to fungie
Dry rot
Wet rot
Brown rot
White rot
Blue stain
Heart rot
Sap stain
Dry Rot in Timber
Dry rot is caused by a certain type of fungi that eats wood for their living. They make food by converting timber into dry powder form. This occurs mainly when there is no ventilation of air or if the wood improperly seasoned. Absence of sunlight, dampness, presence of sap will increase the growth of dry rot, causing fungi. This can be prevented by using well-seasoned wood and also by painting the timber surface with copper sulfate.
Wet Rot in Timber
Wet rot is caused by fungi that decompose the timber and convert it into a grayish-brown powder form. Wet rot causing fungi growths mainly when there are alternate dry and wet conditions of timber.
Brown Rot in Timber
The cellulose compounds of the wood are consumed by certain types of fungi, which then makes the wood brownish, and this defect is called brown rot.
White Rot in Timber
Some types of fungi attack lignin of timber and leaves cellulose compounds; hence the wood will turn into white color, which is called white rot.
Blue Stain in Timber
Blue stain is a defect caused by some kind of fungi, which makes the timber bluish.
Heart Rot in Timber
Heart rot is generated in the trees when fungi attack the heartwood through its newly formed branch. This type of fungi makes the tree hollow by consuming heartwood. This defect is known as heart rot.
Sap Stain in Timber
When the moisture content in the timber is more than 25%, some types of fungi attack the sapwood and make it discolored. This type of defect is known as a sap stain.
Twisted Fibers in Timbers
When the tree in its younger age is exposed to high-speed winds, the fibers of wood gets twisted. This type of wood is not suitable for sawing. So, this can be used for making poles, posts, etc.
Coarse Grain Defect in Timber
The age of a tree can be known by the number of annual rings. For fast-growing trees, the gap between the annual rings is very large. This type of tree is called as coarse-grained tress, and timber obtained from them is of less strength.
Callus
The wound of the tree is covered by soft skin, which is called a callus.
Druxiness
Druxiness is a defect of timber in which the top surface of timber indicates white spots. These spots will give the access to fungi.
Timber Foxiness
When the timber is stored without proper ventilation, the trees growing near the banks of water bodies and over matured trees may exhibit this type of defect. Foxiness is generally indicated by red or yellow spots.
Dead Wood
The wood obtained from the cutting of the dead tree is light in weight and is actually defected. It is reddish in color and its strength is very less.
Burls
Burls are uneven projections on the body of the tree during its growth. These are mainly due to the effect of shocks and injuries received by the tree during its young age.
Chemical Stain
Chemical stain is formed on the wood by the action of any external chemical agents like reaction by the gases present in the atmosphere etc. The stain area gets discolored in this defect
Knots in Timber
The central part or stem of a tree is majorly used in the conversion of timber. Branches from the stem are removed, and the whole rounded stem is taken. But the base of branches forms a mark on the stem, which results in dark-colored stains on the surface after conversion. This dark-colored stains are due to the continuity of wood fibers. These dark-colored rings are known as knots.
Water Stain
When the wood is in contact with water for some time, the water will damage the color of the wood and forms a stain on its surface. This defect is called as water stain.
Rind Galls
Rind galls are curved swellings of trees which are formed at a point where a branch of the tress is improperly removed or fell down.
Wind Cracks in Timber
If the wood is exposed continuously to the high-speed winds, the outer surface shrinks and forms crack externally, which are called wind cracks.
Shakes are nothing but cracks which separate the wood fibers partly or completely.
Defects in Timber During Seasoning
Bow
Cup
Check
Split
Twist
Honeycombing
Case hardening
Collapse
Warp
Radial shakes
When the converted timber is stored for a longer time, some timber planks may have a curve along its length, which is known as Bow.
If the timber planks curve along its width, then it is called Cupping of timber.
Check is the formation of a crack in the wood, which will separate the wood fibers. They form due to over seasoning of timber.
Split forms when a check extends from one end to the other end, which will split the wood into a number of pieces.
Twist forms when the timber piece is distorted spirally along its length. It looks like a propeller blade after twisting.
Honey combing occurs in the inner part of the timber, which cannot be identified by just seeing. It is mainly due to stresses developed during the drying of timber.
Case is nothing but the top surface of wood, which dries rapidly during seasoning, but the inner part didn’t. Then this defect is called as case hardening.
During drying, some parts of the wood may dry rapidly while some may not. Because of this, improper drying shrinkage of wood occurs, that results in the defect called collapse.
Warping is the loss of shape of wood due to stresses developed during drying. Cupping bowing, twisting of wood come under warping.
Radial shakes develop after the tree being felled down and exposed to the sun for seasoning. In this case, the cracks run radially from bark to the pith through annual rings.
Defects in Timber During Conversion
Diagonal grain
Torn grain
Chip mark
Wane
During the conversion of timber, different cutting saws are used. The cutting should be done properly. If there is any improper cutting by the saw, then a diagonal grains will appear.
In the conversion, many tools are used. If any of the tools or any other heavy things are dropped accidentally on the finished surface of timber it will cause small depression, which is called torn grain.
When the timber is cut through the planning machine, the parts of the machine may form chip marks on it. Usually, they are indicated by chips on the finished surface.
The edge part of the timber log contains a rounded edge on one side because of its original rounded surface. This rounded edge is called wane.
Defects in timber due to Insects
Termites
Beetles
Marine borers
Termites also known as white ants which form a colony inside the timber and eat the core part of the timber rapidly. They do not disturb the outer layer of timber, so one cannot identify their presence. The trees in tropical and sub-tropical regions are mostly affected by these termites. However, some trees like teak, Sal, etc. cannot be attacked by termites because of the presence of termite preventing chemicals in their cellulose part.
Beetles are a type of insects that destroy the sapwood of the tree and make a tunnel-like hole from the bark. Usually, the diameter of the hole is around 2 mm. They convert sapwood into powder form, and larvae of these beetles use these holes. Almost all hardwood trees can be prone to damage by these beetles.
Marine borers are found near coastal areas. They do not consume wood, but they make large holes of diameter up to 25mm in the timber to live inside it. They excavated up to 60mm deep in the wood. The wood attacked by marine borers is of less strength and discolored. They can attack all types of trees present in their region.
bacic butt joint
There is no more basic wood joinery than the butt joint. A butt joint is nothing more than when one piece of wood butts into another (most often at a right angle, or square to the other board) and is fastened using mechanical fasteners. This type of joint is often used in wall framing on construction sites. Learn tips for using a butt joint, as well as when to choose another wood joinery type.
mitered butt joint
A mitered butt joint is nearly the same as a basic butt joint, except that the two boards are joined at an angle (instead of square to one another). The advantage is that the mitered butt joint will not show any end grain, and as such is a bit more aesthetically pleasing. However, the mitered butt joint isn't all that strong.
half lap joint
The half-lap joint is where half of each of the two boards being joined is removed so that the two boards join together flush with one another. This type of wood joinery can obviously weaken the strength of the two adjoining boards, but also is a stronger joint than butt joints. There are a number of projects where this type of wood joint is quite desirable, in spite of its drawbacks.
Tulng and grove joint
When joining two boards square to one another along a long edge, one can simply butt the joint together and hold it with fasteners. However, the tongue and groove joint is much stronger and provides more adjoining surface areas, which is particularly useful if you're going to glue the joint.
mortise and tenon joint
The mortise and tenon is a classic wood joinery method. These joints have been used since the early times of woodworking, and are still among the strongest and most elegant methods for joining wood. Learn methods for creating tight, beautiful mortise and tenon joints.
biscut joint
Another method for joining boards along the edges (like the tongue and groove joint) is to cut slots and use beechwood wafers (known as a biscuit) to hold the boards in place. This is a very useful modern woodworking joint, particularly for creating table tops, relying on glue and the swelling of the beechwood biscuit to hold the boards in place.
pocket joint
The pocket joint is a type of wood joinery that involves cutting a slot and pre-drilling a pilot hole at an angle between two boards before connecting the two with a screw. This pre-drilling needs to be very accurate, so it is typically accomplished by use of a commercial jig. Pocket joints work great for cabinet face frames and other similar applications where a lot of strength is not needed. Learn the steps to creating pocket joints in your woodworking projects.
Dado
A dado is nothing more than a square-grooved slot on one board where another board will fit. Similar to tongue and groove joinery, this is a commonly-used wood joint for connecting plywood, such as building cabinetry. Learn how to properly cut a dado, and when to use one.
Rabbet
Another common wood joint used in cabinetry is the rabbet. A rabbet is essentially a dado cut along the edge of a board. Rabbets are often used at the back of cabinets and other similar assemblies for attaching the back to the sides of the box, adding a considerable amount of strength to the assembly. Learn how to cut clean rabbets and when to use them.
Through Dovetail Joint
Of all wood joinery methods, the through dovetail may be the most revered. A classic through dovetail is beautiful and very strong and adds a touch of class to any piece. There are a few methods for creating through dovetails, from hand cutting to machining with a jig. Learn the keys to a quality through dovetail joint and how to create them.
Half-Blind Dovetail Joint
There are situations where a dovetail joint is the connection of choice, but both edges of the dovetails should not be visible. A perfect example is a drawer front, where you don't want to see the end of the through dovetail on the face of the drawer. For this type of joint, the best choice is a half-blind dovetail. Learn how to build a clean, strong and beautiful half-blind dovetail joint and when to use this type of wood joinery.
Sliding Dovetail
A sliding dovetail is a versatile joint with a lot of possible uses. A good way to think of it is as a locking dado. Learn the keys to building a clean sliding dovetail joint, and when to use one.
box joint
Dovetail joints are beautiful and strong, but not always practical. A box joint is a simpler alternative to the dovetail joint. Learn how to build consistent and strong box joints in your woodworking projects.