Unit 115 - Produce woodworking joints/Timber defects Conversion

Unit 115 - Producing wood working Joints

-Timber Conversion
-Timber Defects
-Woodworking Joints

Word Cloud

Write something you know about Timber conversion, Timber defects and Woodworking Joints...

Definition

"Timber conversion is the process of turning a log into a pile of usable planks or boards."

Timber Conversion

​

​What is "Felling"?...

Types of Timber Conversion

-Quarter Sawn

-Through and Through

-Tangential cut

-Boxed Heart

Through and Through

-Simplest method of conversion

-Cheapest method of conversion

-Economic (Less waste)

-More likely to warp

-More likely to shrink

-Wood is weaker than timber produced in other conversion methods

-Longer annual rings

​Positives

Negatives

Through and Through

​Through and through also known as flat slab or slash sawing is the simplest and most economical method of converting timber.
Although there is very little wastage with this method, the majority of the boards produced are prone to large amount of shrinkage and distortion.

Twisting

Types of Timber defect

Why does Twisting appear?

Tangential sawn

-Produces the strongest timber, normally
used for floorboards and joists (Don’t
split easily).

-Less likely to warp

-Less likely to shrink

-Attractive flame figure produced.

-Expensive

-More waste produced than other
methods (e.g. through and through)

-Some boards are prone to cupping

​Positives

Negatives

​A tangent is a line that touches a circle at one point only.

​

Tangential sawn

Tangential sawn timber method of conversion is used to provide floor joists and beams, as it gives the strongest timber. It is also used on pitch pine and douglas fir for decorative purposes to produce "flame figuring" or "Fiery grain".

Quarter Sawn

-Less likely to warp

-Less likely to shrink

-The wood produced is stronger

-More attractive grain

-Shorter annual rings

-Wood produced is more stable wears
more evenly (good for flooring)

-More complex method of conversion

-More expensive method

-Takes longer to complete

-More waste is produced

​Positives

Negatives

Quarter sawn

​Quarter sawn timber, produces the best quality timber. However it is also the most expensive, both in time involved and material wastage. It produces the greatest quantity of "rift" or "radial sawn" boards, which are generally superior for joinery purposes.

Multiple Choice

Which of the following images shows the timber conversion "Through and Through"?

Multiple Choice

What is timber conversion?

• Converting wood to projects

• Converting seeds to trees

• Converting logs to boards

• Converting land to forestry

Multiple Choice

Which type of sawn timber generates very little waste?

• Through and through (Live sawn)

• Quarter sawn

• Tangential sawn (Back sawn)

• Boxed heart sawn

Multiple Choice

Which type of sawn timber generates the strongest boards for Joinery Products?

• Tangential sawn

• Through and Through

• Quarter Sawn

• Boxed Heart

Multiple Choice

Which type of sawn timber generates the strongest boards for structural purposes?

• Tangential sawn

• Through and Through

• Quarter Sawn

• Boxed Heart

Multiple Choice

Above is a common natural defect that can happen when logs are converted. What is its correct name?

• Bowing

• Cupping

• Winding / Twisting

• Shrinkage

Definition

"A Defect is taken to be any irregularity occurring in or on the timber which may lower its strength, durability, utility value or diminish its appearance. Defects may be 'natural' which occur whilst the tree is growing, or 'artificial' as a result of poor conversion, seasoning or handling after felling."

Timber Defects

Why does Cupping appear?

​Cupping

Types of Timber defect

Bowing

Types of Timber defect

Why does Bowing appear?

Why does Twisting appear?

​Twisting

Types of Timber defect

Case Hardened

Types of Timber defect

What causes case hardening?

Match

Match the following timber defects...

Cupping

Bowing

Case Hardened

Winding/Twisting

• Cupping

• Bowing

• Case Hardened

• Winding/Twisting

Multiple Choice

The following definition is regarding which timber defect?...

_____________ is caused by too rapid drying, resulting in the outside cells of the timber drying and hardening, sealing off the moisture in the central part of the board.

• Winding

• Cupping

• Bowing

• Case Hardened

Cup shake

Types of Timber defect

What is a Cup shake / Ring shake?

Heart shake

Types of Timber defect

What is a Heart shake?

Star shake

Types of Timber defect

What is a star shake?

Match

Match the following timber defects with the correct names...

Star shake

Heart shake

Cup shake

• Star shake

• Heart shake

• Cup shake

Definition

"Woodworking joinery is the craft of connecting and securing the separate members of the wooden construction  to one another by means of specific cuts on the ends and/or sides of the members."

Woodworking Joints

Word Cloud

Name different types of woodworking joints...

Mortice & Tenon

In a through mortice and tenon joint a single rectangular tenon is slotted into a mortice.

Stub Mortice & Tenon

In a stub mortice and tenon joint the tenon is stopped short to prevent it protruding the member.

Half Lap Joints

A half-lap joint is a carpentry and woodworking joint made between two pieces of wood. This joint involves removing half the thickness of both boards and then mating them together to create a thickness that is uniform with the rest of the boards.