The conversion of timber
By Mikayla Harrison
There are different methods of doing this;
The method of live sawing
Characteristics, advantages, disadvantages and common uses.
- Most economical method of converting timber.
- Simplest method of converting timber.
- Highest recovery rate.
- Cheapest milling cost of any methods for converting timber.
- No turning required.
- No highly-skilled labour required.
- Suited for cheap construction work.
Although...
- The method lacks versatility.
- Is not suited for production of timber of various sizes/ quantities.
- Prone to excess warping.
- Prone to un-even shrinkage.
Used for...
- Items such as fence paling and crates.
The method of cutting tangentially
Characteristics, advantages, disadvantages and common uses.
- Faces are tangential to the growth rings.
- Flexible method.
- Well suited to securing high-grade timber from varied and/or faulty logs.
- Best suited for sawing around faulty parts.
- Very little waste made.
- Timber that possess distinct growth ring are usually back sawn as it's most decorative.
Although...
- Can cup or warp from the heart of the board.
- Boards prone to shrinking in width.
Uses...
- Axe and hammer handles.
- Floor and ceiling joists.
The Method of quarter sawing
Characteristics, advantages, disadvantages and common uses.
- Faces are generally parallel to the medullary rays.
- Faces are generally at a right angles to the growth rings.
- Wears evenly.
- Recovery rate is good.
- Seasons evenly.
- Retain their shape well.
- Do not cup or check at all.
Although...
- Have to turn the log frequently.
- Timber is lost through waste.
- Slow seasoning process.
Uses...
- Used for architraves and flooring boards.
Seasoning of timber
Unseasoned timber holds water in it, seasoning the timber merely dries out most of this water to the best moisture content amount. Why so?
1) To keep checking, warping and shrinkage of the timber to the bare minimum.
2) To keep weight of the timber to a minimum which will in turn keep freight costs to a minimum.
3) To keep wood-boring insects in the timber to a minimum which will in turn keep liability to a minimum.
4) To keep mould to a minimum.
5) To keep maximum strength in the wood.
6) To maximise the bonding qualities in the wood so that things like finishes will adhere or stick to their potential.
7) To minimise dark colour in wood.
Methods of which this is done...
1) Air seasoning
2) Kiln seasoning
and...
3) Combined seasoning
Bibliography
Mr Finnity's Woodwork textbook
http://www.timbergreenforestry.com/Live%20Sawing.html
http://www.geoffswoodwork.co.uk/conversion.htm
http://timbertech.wikispaces.com/file/view/Conversion+of+timber.pdf
www.woodtreks.com/why-sawyers-plane-flat-rift-or-quarter...lumber/315/
au/Wood-Product-Categories/Sawn-Timber
http://en.wikipedia.org/wiki/Quarter_sawing
http://www.geoffswoodwork.co.uk/seasoning.htm
www.dpi.nsw.gov.au/__data/assets/pdf_file/.../Seasoning-of-Timber.pdf
www.timbergreenforestry.com/Live%20Sawing.html
www.forestryforum.com/board/index.php?topic=27916.0