Unit 15 Natural and Manufactured Timbers Flashcards
What are the 2 main types of natural timber
Softwoods
Hardwoods
What are manufactured timbers?
Timbers made from wood chips, veneers, or fibres glued and pressed together
What trees do softwoods come from?
Coniferous trees - evergreen usually has needles and cones
What trees do hardwoods come from?
Deciduous trees - usually broad leaved tree drops leaves in winter
What is the term used to describe cutting down trees?
Felling
What is the term used to describe the process of cutting/sawing trees in to useable shapes?
Timber conversion
What is the term used to describe the process of reducing moisture in timbers that have been felled
Seasoning
What 2 main types of stock finish are timbers produced in
Rough sawn - can have splinters
Planed all round - planed on each side to give a nice finish
Name 2 ways of seasoning timbers
Air-drying
Kiln-drying
Why do you need to reduce the moisture content of timbers newly felled?
Timbers contain over 50% moisture. Natural uneven drying can cause warping, splitting and bowing
What are timber veneers?
Very thin sheeting of natural timber, often used on top on MDF chipboard to make them look nicer
Name 2 advantages of manufactured board
Available in large sheets
Very stable
No defects - warping splitting etc
No knots or resin that can make hard to use
Smooth finish - little prep
Makes use of waste timber
Available in different finishes, veneers, laminates
Name 2 disadvantages of manufactured board
Adhesives used to make them have VOCs Dust can be harmful to breath in Tools can blunt because of adhesives in materials Some tools can be used - chisels Edges hard to finish Most Can absorb moisture easily and warp
Name 3 types of softwood
Redwood Cedar Parana pine Mexican pine Larch Spruce
Name 3 types of hardwood
Ash Beech Mahogany Oak Balsa
Name 3 types of manufactured board
MDF - medium density fibreboard Chipboard Softwood Plywood Hardwood plywood Marine plywood Hard board
Name 3 properties of hardwoods
Less porous Denser cell structure Most more hard wearing Most less prone to rotting Tend to be more expensive Take longer to grow Not often considered very sustainable (Balsa wood is a hardwood but is fragile and lightweigh often used in modelling)
Name 3 properties of softwoods
General more porous cell structure
Absorb moisture easily
(Cedar however contains natural oils which protect it outside)
Relatively cheap
More sustainable because it’s widely planted and grows faster then hardwoods
Explain 3 reason why timbers have finishes
To protect them from warping and bowing
To protect from staining and discolouration
To prevent them rotting
To prevent splintered and splitting
To add colour and texture
To make softwoods look more like hardwoods and more expensive
What 3 finishes can be applied to timbers
Water-based paint - not durable Solvent-based paint - can have VOCs Danish oil Liming wax Beeswax Stains - man made and natural Varnish - colours and clear
Name 3 types of timber stock form
Planks Dowels Post - square length Moulding - architrave skating boards Boards - manufactured boards
Name 3 fittings or fixtures you can use with timbers
Nails - round wire, panel pin, clout nail
Screws - slotted, Phillips, pozidriv, Allen, Torx
Knock-down fittings - block, cross dowel fitting, cam lock fitting
Hinges - flush hinge, butt hinge, butterfly hinge
