Timbers Flashcards
What is Forestry Management
Sustainable cycle of planting, cultivation and harvesting
What is Timber Conversion
When Felled trees are cut into manageable lengths and converted into boards or planks
What are the Two main timber finishes
PAR (Plained All Round) and Rough Sawn
What is Green timber
Newly felled and unseasoned timber with a moisture quantity of 50%+. Very hard to work with as outdoor applications should have 20% or less and indoor 10% or less. Moisture must be removed to gain strength and reduce dimensional movement.
Name two Ways to reduce moisture content
Season the wood by air drying or kiln drying (Kiln drying less prone to faults)
Name all the Faults
These occur as timbers dry:
Bowing
Splitting
Crooking
Cupping
Twisting
What Is Sustainable Timber
Timber supplies approved by the Forest Stewardship Council that regulates that timber supplies are sustainably managed and harvested
What are Manufactured Boards
They come in large sheets, often made from recycled or waste wood and adhesives. They are often made using lamination or compression techniques and covered with veneers of high quality timber.
What is Lamination
The technique of layering materials using heat, pressure and adhesives. Strips of timber are glued together and placed over a jig. Clamps or a vacuum press are used to exert pressure while the adhesive dries.
What is Compression
Compression uses adhesives, heat and pressure to combine shreds, chips or pulp to produce a larger board. These boards are often covered with a melamine or chemical laminate.
What is Rotational Veneer
Veneer can be made by rotating a tree trunk to create a long ribbon of thin veneer, cut to length
What are the advantages of Rotational Veneer
Available in long sheets with few faults or defects, aesthetic flows such as knots can be easily eliminated, made of recycled products, vast range of surface finishes.
What are the disadvantages of Rotational Veneer
Adhesives used can be hazardous if inhaled, edges are hard to finish and the boards are prone to absorbing moisture
Name the Common Stock Forms
Plank, Boards, Mouldings, Dowels and Sheets
What is a moulding
timber components with a shaped profile
What is a Countersunk Screw
A screw that gives a better hold and a neater finish. Also allows a plug or cap to be used to cover the screws head to create a clean and unbroken appearance.
What are Knock-Down Fittings
Often used for self assembly furniture. Block with hole in attached by nails.
What is wasting and abrading
The process of removing layers of wood e.g. sanding to get a better finish
What is wood turning
When a Lathe is used to turn wood on a plate or between two points while it is shaped by tools
How is wood bent
It is steamed to make it more malleable and then the softened timber is forced around a jig using a strap and left to dry.
Advantages of Engineered or Manufactured Wood
Can be mixed with glues to give greater strength and stability making it better for construction and domestic uses. Also reuses waste wood products
Why is flat pack furniture good
less expensive, arrives boxed making it easier to store and transport, easy to assemble. Less aesthetic though
What are the Advantages of Commercial Manufacturing
CNC machinery ensures mass produced timber components are equal sized parts. Helps minimize waste materials. Screw Holes, slots and patterns can be cut in one process. Machines work quickly and efficiently.
What are the Advantages of Commercial Turning
CNC wood lathes can create identical cylindrical components once programmed
What are the Impacts of Automation and Mechanisation?
Improvements in manufacturing methods and the increase in the quality controls consistency and accuracy means products can be easier mass produced
What are the ways wood can be protected or visually enhanced using treatments?
Preservative
Wax
Oil
Paint
Stain
Varnish
What does treating timber do and how can this process be enhanced?
Helps extend life of the wood dramatically and a hydraulic press can be used to force treatment deeper into the timber
What are the advantages and disadvantages of commercial finishing
Modern finishes can extend the life of timbers and can be sprayed on by hand or machine. However they have poor environmental impacts and may damage the environment.
What are hardwoods?
Woods usually obtained from deciduous trees - stronger and hard wearing but take long time to grow
What are softwoods?
Woods usually taken from coniferous trees - cheaper and easier to shape and take a shorter time to grow
What are manufactured boards
Made from the pulped waste sections of trees stuck together with adhesive and able to come in specified sheet forms
What are the properties of Ash?
Hardwood - tough and flexible -shock resistant - finishes well- used in sports equipment, hand tools and ladders
What are the properties of Beech?
Hardwood - Strong - dense, close grain - prone to warping and splitting - used in furniture, toys and bench tops
What are the properties of Mahogany?
Hardwood - Strong and durable - easy to work with and finishes well -used in high end furniture
What are the properties of Oak?
Hardwood - Strong and Lightweight - used in flooring, furniture and timber framed buildings
What are the properties of Balsa?
Hardwood - Strong and durable - very lightweight - if too thin can break easily - used in models and floats/rafts
What are the properties of MDF?
Medium Density Fibreboard - rigid and stable and easy to shape/use - used in flat pack furniture, kitchens and toys
What are the properties of Plywood?
Laminated board that is very stable - used in furniture, shelving and fencing
What are the properties of Chipboard?
Not as strong as MDF or Plywood - very cheap and made from recycled materials - used in flooring, low end furniture, kitchen units and cupboards
What are the properties of Larch?
Softwood - Tough and durable - good water resistance - used in fencing, cladding, decking and outdoor furniture
What are the properties of Pine?
Softwood - Lightweight - easy to work with - can be very knotty - used in furniture, construction and window frames
What are the properties of Spruce
Softwood - Lightweight and easy to work with - used in furniture, musical instruments and construction
