1.5-Wood finishes Flashcards
What is the purpose of finishing wood
- protect the wood from absorbing moisture
- protect against decay
- protect against insect attack
- enhance appearance of final product
What three ways can wood degrade
- wet rot (alternating wetness and dryness means moisture is absorbed into wood and remains below surface. Leads to breaking of wood fibres and fungus spreads through wood. Wood becomes soft, wet and crumbly)
- dry rot (a different fast spreading fungus causes dry rot, which can turns wood into a dry, soft, powery state)
- insect attack- furniture beetle attacks softwood and heardwood, deathwatch beetle attacks hardwood. Both lay eggs in cracks in the wood. Hatched larvae eat in the wood, creatig tunnels. When beetle forms, it eats its way out of wood via flight hole
What must be done before applying a wood finish
- make the surfaces smooth either by planing and/or sanding with glass paper (in grain direction) using progressively finer grades
- remove all dust with a cloth before finish applied
Wood finish- polyurethane varnish/ acrylic varnish- method of application and how they enhance appearance or prevent decay
polyurethane varnish- available in glass, satin and matt, clear or colours
acrylic varnish- apply a thin coat with a brush in grain direction. Several thin coats can be applied, rubbing down between coats with glass paper
-provides a hard, tough, heat/waterproof finish. Clear finish allows the grain to be seen through finish
Wood finish- water based paints- method of application and how they enhance appearance or prevent decay
- available in gloss, satin, matt and metallic effects. Applied with a brush, roller or spray. Wood knots to be treated with knotting solution to prevent resin oozing out. Surface then primed and an undercoat applied prior to paint finish
- paint provides protection and colour. Applied indoor and outdoor. Softwoods. Makes surface more aesthetically pleasing, tougher, harder, resistant to moisture
Wood finish- stains- method of application and how they enhance appearance or prevent decay
- available in different colours/types, applied with brush, roller, spray, surfaces should be grease free prior to application
- help colour and enhance the grai, stains used to colour an inexpensive wood to make it look expensive or to add colour. No specific protective properties
Wood finish- colour wash- method of application and how they enhance appearance or prevent decay
- available in different colours, applied with wet sponge
- used to colour wood to make it more aesthetically pleasing or to add a vintage style while allowing grain to show
Wood finish- wax- method of application and how they enhance appearance or prevent decay
- available in clear and coloured waxes for indoor products. Applied with brush or stockinet cloth then once dry, buffed with a clean lint free cloth
- can be buffed for high gloss ginish. Increases surface hardness and toughness. Clear finish allows grain to be seen through finish
Wood finish- yacht varnish- method of application and how they enhance appearance or prevent decay
- available in high gloss/satin
- applied with brush or sprayed directly onto wood
- suitable for woods that are outside, increases toughness+harndess+weather resistance
Wood finish- danish oil- method of application and how they enhance appearance or prevent decay
- available in clear and colour tints. Apply with a lint free cloth, rub oil into surface of wood and in direction of grain. Leave wood to absorb oil for 5 mins then rub away excess oil with clean cloth. Lightly sand or rub with wire wool to open up grain
- maintains natural appearance, soaks intol wood and enhance grain. Not hardwearning but regular application and subsequence coats build up a matt, water resistant finish
Wood finish- teak oil- method of application and how they enhance appearance or prevent decay
- available in clear tint. Apply with a lint free cloth, rub oil into surface of wood and in direction of grain. Leave wood to absorb oil for 5 mins then rub away excess oil with clean cloth. Used for naturally oily woods
- outdoor wood products to improve weather resistance and resistance to fungal/insect attack. Aesthetically pleasing as grain enhanced
Wood finish- yacht varnish- method of application and how they enhance appearance or prevent decay
- wood placed in a pressure vessel containing a solution consisting o copper sullphate and other preserving salts. Vacuum and pressure controlled to force preservative deep into the fibres of the wood and wood steam dried
- protect wood for up to 50 years from rot, insect and fungal attack and weathering. Decking, overhead cable poles, harbour or bridge construction
