Seasoning, Drying and Faults

Question 1

Why should timber be dried and not left wet/moist?

Answer 1

Newley felled timber contains 50% moisture,
Moisture in the timber will evaporate overtime cause change in size, warping, twists and cups,
High moisture = more insects likely to attack, woodworms

Question 2

What is Air drying?

Answer 2

Planks are stacked outside with wooden spacers allowing air to flow around the timber,
It is a slow method = 1 inch thickness = a year of drying time for timber,
You can only get the moisture content down to that of the air around it usually 20%,
Could warp but a very cheap method

Question 3

What is Kiln Drying?

Answer 3

The timber is mounted on a trolly that is wheeled into a kiln, that has steam fed into it,
Faster than air drying = 1 inch thickness a week,
Can be brought down to around 8% moisture content,
Temperature and humidity are controlled,
Planks are separated with beams to allow air to flow in,

Question 4

What are the types of defects?

Answer 4

Shrinkage, Shakes, Bow, Twist, Split, Knotholes, Wane, Cup, Checks, Crooks

Question 5

Why are the defects bad?

Answer 5

This makes it very hard to manufacture products from the wood.