Timber Things I Cant Remember Flashcards
What is pressure treatment
A process that forces chemical preservatives into the wood
Describe the pressure treatment process
Timber loaded into treatment vessel and a vacuum is applied to remove any air
The vessel is flooded with preservatives
Hydraulic pressure is applied, forcing preservatives deep into structure of the timber
Final vacuum extracts excess preservative solution
Low pressure inside timber draws in surface solution
Treated timber is left to dry
Why is timber pressure treated
To protect wood from insect attack, or fungal decay
Explain toxicity of woods
Both hardwood dust and softwood dust can cause respiratory irritation. The sap can also be hazardous to health.
Employers should provide ppe and have extraction/ ventilation systems in place
Disadvantages of natural wood as a manufacturing material
The strength properties decrease when wet
Highly combustible
Susceptible to insect attack and rot
Has different properties in different directions
Why are dowel joints used in flat pack furniture
They don’t require any specialist skills or complex tools
Why are comb joints stronger than butt joints
The combs create an increased gluing surface area
Why are dovetail joints good for drawers
They have directional strength. Once glued, they are impossible to pull apart
Name 3 knock down fittings
Modesty blocks, barrel nut and bolt, cam lock connector
Name the 3 forms of screws
Slot head
Phillips
Pozidriv
Name the 2 methods of catholic protection
Impressed current
Sacrificial anodes
Wood turning methods
Turning between centres
Turning on a faceplate
Turning in a chuck
Turning between centres
Use two machine, a spindle such as chair legs and table legs
Turning on a faceplate
Used machine items such as domes or bowls
Turning in a chuck
Used to grip the item while it is machined such as drilling the end of a spindle or holding the base of a small bolt to allow access to the inside surface
