Joining Techniques Flashcards
1
Q
Adhesives
A
PVA
Tensol cement
Liquid polycement
Contact adhesive
Epoxy resin
2
Q
PVA
A
- very effective on wood if both surfaces of the joint are edge grain.
- a properly glued joint can be as strong as a single piece of wood.
- won’t work on end grain surfaces.
3
Q
Tensol cement
A
- joins plastics (eg acrylic) together permanently.
- glue applied to both surfaces.
- clamped for 24hrs to give a permanent joint.
- cant clean excess off, leaves strings,
4
Q
liquid polycement
A
- more appropriate for plastic.
- works by capillary action.
- cleaner and easier to use.
- water like consistency.
5
Q
contact adhesive
A
- can be used to join plastics.
- adhesive is applied to both surfaces and when appears to be dry is pushed together.
- used for large surface areas.
6
Q
epoxy resin
A
- many adhesives are plastics themselves.
- Araldite is an epoxy resin that hardens when a second chemical is added (catalyst).
- can bond most materials including some plastics.
- messy and smelly
- mix two parts for 1 minute.
7
Q
wood joints
A
can be designed to hold without the use of glue or fasteners.
8
Q
types of wood joints
A
half mitre
mortise and tenon
dove tail
lap joint
bridal joint
rebate
finger joint
dowel joint
9
Q
compare a mortise and tenon to a dowel joint
A
compared to a mortise and tenon, a dowel joint is a poor joint. Much of the surface of the dowel joint is end grain, to which glue adheres to poorly. In a mortise and tenon joint most of the surface of the joint is longitudinal grain.
10
Q
mechanical joining
A
- temporary/semi permanent
- various mechanical fasteners used
- nails/ screws
- nuts and bolts
- pop rivets
11
Q
thermal joining
A
heat is used to cause a joint in a variety of ways: soldering, braising, welding
12
Q
soldering
A
- a process in which two or more metal items are joined together by melting and flowing a filler metal into a joint.
- filler metal has a relatively low melting point.
- in a soldering process heat is applied to the parts being joined, causing the solder to melt and be drawn into the joint by capillary action.
- soft soldering, hard soldering, silver soldering
13
Q
brazing
A
- a filler metal or alloy is heated to melting temp.
- quick, doesn’t need to much heat.
- widely used in the tool industry to fasten hard metal tips to tools such as saw blades.
14
Q
MIG welding
A
- metal inert gas
- a form of arc welding
- used for general welding, mild steel
- as well as welding it can be used for cutting plate metal.
15
Q
TIG welding
A
- tungsten inert gas
- a form of arc welding
- used for welding specialist materials such as aluminium and stainless steel.
- has a filler rod instead of a consumable wire.
