Timbers - Specialist Technical Principles

• Timbers are fibrous meaning they have good tensile and compressive strength
• Sources and origins

  • Hardwood - coniferous
  • Softwood - deciduous
  • The process of conversion is changing a tree into manageable lengths: timber
• Freshly cut, "green", timber has a high water content

  Dried, "seasoned", timber has been dried either in a kiln or air seasoned
• Use of material properties in commercial products

  • Beech - hard wearing used for eg. toys and tool handles
  • Chipboard - dense and flat. Used for flat pack furniture
  • > covered in a polymer laminate as chipboard absorbs water and breaks
• Stock forms and sizes

  • "Rough cut" is used for eg. fence posts or construction
  • As opposed to smooth, planed edges
  • Planed timber is more expensive
  • PSE - planed square edge - one edge planed
  • PAR - planed all round - used when timber will be seen
• Scales of production


  • Prototype - eg lollypop sticks
  • Batch - jig used for repeated cutting, eg. from a template
  • Mass - assembly line is used
  • Continuous
• Tools, equipment and processes

  Marking timber:

  • try square - 90° to an edge
  • mitre square - 45° to an edge
  • sliding bevel - a set angle to an edge
  • Marking gauge - scratches a line parallel to an edge
  • Mortise gauge - scratches a pair of parallel lines to an edge
• Tools, equipment and processes

  Cutting:

  • rip saw - rough
  • Tenon saw - straight lines
  • coping saw - thinner wood. can deal with curves
• Tools, equipment and processes

  Drilling:

  • twist drill - set diameter hole
  • Counter sink bit - for the top of the screw
• Tools, equipment and processes

  Shaping:

  • chiselling - up to a cut or between two cuts
  • planing - to smooth or add an angles, chamfered edge
  • Sanding
• Commercial Processes

  Routing:

  • Cutting bit rotated at high speeds
  • Can follow jigs or patterns

  Turning:

  • wood rotated at high speeds
  • Tool held to the edge removing material whilst spinning
  • Used for spindles
• Accuracy and Quality control

  Digital vernier calipers for accuracy or tape measure if the measurement can be rough
• Surface treatments and finishes

  • Paint
  • Wood Stain
  • Oil and wax
  • Varnish
  • Pressure treated timber
• Surface treatments and finishes

  Paint:

  • can protect the timber
  • Opaque pain adds colour
  • Can be gloss, matt or silk
  • Sometimes an undercoat is needed
• Surface treatments and finishes

  Wood stain:

  • often designed to look like a different timber
  • > eg. pine can be darkened to look like a hardwood
  • adds some protection however varnish is usually also required
• Surface treatments and finishes

  Oil and wax:

  • Enhance natural look
  • water resistant
• Surface treatments and finishes

  Varnish:

  • shiny appearance
  • Many layers added
• Surface treatments and finishes

  Pressure treated timbers:

  • protective fluid is injected into the timber by placing the timber in a pressurised treatment vessel
  • prolongs the life of the timber
  • more effective and longer lasting treatment method as opposed to drip-treated