Fallibroome Y12 D&T: Joining Stuff to other stuff.

Contact Adhesive

These are rubber based and can be made from synthetic rubbers. pros = Adhesion takes place soon as the two surfaces are placed together. No clamping is required. cons = No opp to reposition the pieces. Relatively expensive.

Acrylic Cement

Dichloromethane works by dissolving the surface of hard plastics. pros = Rapid bonding of arcylics. cons = Expensive. Difficult to appl and give a neat joint.

Epoxy Resin

"The Epoxy resin sets when equal amounts of resin and hardener are mixed together. It then chemically sets to form a very hard material. pros = High strength bonds. Versatile. Heat resistance is good. cons = Expensive. Reaches full strength after a couple of days setting."

PVA - Polyvinyl Acetate

Polyvinyl acetate is a water based adhesive which is coloured white. pros = Water based. Inexpensive. Gives a strong joint. cons = Not waterproof. Surfaces need to be securely clamped.

Hot Melt Glue

Works by heating a stick of glue which resets when cool forming the bond. pros = Range of colours. Quick to harden. cons = not great for final models. safety issues.

Cyanoacrylate (super glue)

They provide instant bonding and clear lines. Easy to use. pros = Strong. Fast acting = Short shelf life. Skin contact.

Polystyrene Cement

"The product works by melting the plastic on application and 'welding' two glued pieces of plastic together to form a strong bond. pros = Strong bond. Can use brush to apply. cons = contain VOC'S. Expensive. "

Machine Screws

"Machine screws have parallel sides with standard threads cut into them. They are usually made from carbon steel and are mass produced. The most common head being countersunk and cheese heads."

Wood Screws

"Wood screws are classified firstly by the shape of the screw head and secondly by the length of the screw itself. They come with three different types of head, countersunk, raised and rounded."

Nuts and Bolts

Nuts and bolts are usually manufactured from low or medium carbon steel.

Nuts

"Specialist nuts are used for particular situations. For example, where nuts and bolts are to be used in places where vibration is an issue, a lock nut could be used."

Bolts

"The diameter of a bolt is always in millimetres and sold in stock or standard sizes. The most commonly used thread form is the ISO metric thread. The other measurement within threads is the pitch. The pitch of the thread is the distance that a screw or bolt with travel through one revolution."

Solid Rivets

Solid rivets are manufactured from soft iron because they need to be ductile and easy to work as they have to be hammered into shape.

Pop Rivets

Pop rivets are usually manufactured from aluminium and instead of being hammered into shape, they are fixed into place using a pop rivet gun.

Oxy-acetylene Welding

"Oxy-acetylene gas welding is commonly used to permanently join mild steel. A mixture of oxygen and acetylene, burns as an intense / focussed flame, at approximately 3,500 degrees centigrade. When the flame comes in contact with steel, it melts the surface forming a molten pool, allowing welding to take place. A filler rod of the same material is often used to complete the joint."

Washers

"Spacers / washers are used in situations where components need to be separated on a shaft. Come in a variety of materials including high density polyethylene (HDPE), nylon and steel. Washers can also be used as spacers, anti-vibration devices and locking devices."

MIG Welding

"Metal Inert Gas (MIG) welding is a form of electric arc welding. MIG welding involves a process where, using an electric current, an arc is struck between the work and an electrode and this is used as the heat source. The filler is in the form of a thin wire and as the welding progresses the wire is gradually fed into the joint. During the operation a flow of inert gas, usually argon, is made to flow over the area being joined. The inert gas acts as an envelope that keeps the oxygen away from the joint. This prevents oxidation on the joint and therefore helps to keep the weld sound."

Brazing

Brazing is a method of joining mild steel to mild steel. Uses a second material called a spelter.

Hard Soldering

"Hard soldering is a general term for silver soldering and is similar to brazing. These are very similar or molten and that the filler alloy has to have a lower melting temperature range than the metals being joined. The melting temperature of hard solder ranges from 625°C to 800°C."

Soft Soldering

Soft solders are used for airtight or watertight joints which are not exposed to high temperatures.

Wood Joints

Strong, permanent and neat-looking joints in wood are achieved using one of the many types of frame joint. Frame joints are right-angled.

Knock down Fittings

Much furniture is sold in flat packs. This makes it easy to transport and store. The customer then has to assemble it at home. Usually knock-down (KD) fittings are used. Usually these are made from a plastic such as nylon.