This document discusses different types of adhesives used in woodworking. It describes various adhesives like PVA glue, epoxy resin, contact glue, superglue and hot melt glue. It explains their properties such as shelf life, pot life, closed assembly time, how they work through specific and mechanical adhesion. It provides guidance on using different adhesives for specific applications like veneering, bonding wood or metals.

1. WOOD
MATERIALS TECHNOLOGY
4th Edition

2. Chapter 28
Adhesives

3. Adhesives
 Shelf life
– Best before date – how long the glue will keep in its
container or packaging
 Pot life
– The time that the glue remains usable in a pot
– Also known as open assembly time
 Closed assembly time
– The time you have to adjust and cramp the pieces before
the glue starts to set

4. How a glue works
 Specific adhesion
– The holding power of
the glue itself
 Mechanical adhesion
– The grip it has on the material,
e.g. cracks, crevices, pores

5. Types of adhesive
 Scotch glue/pearl glue
 PVA glue
 Casein glue
 Contact/impact glue
 Formaldehyde glue
 Epoxy resins
 Aliphatic (yellow) glue
 Superglue
 Hot melt glue

6. Scotch glue/pearl glue
 Scotch/pearl/animal glue
 Water soluble – dissolves in
water
 Strong smell
 Not heat resistant
 Long shelf life
 Must be prepared in glue
pot
 Used for veneering

7. PVA glue
 PolyVinyl Acetate (PVA)
– Water soluble
– Water-resistant types
available
– Ready to use from container
– Strong bond
– Requires cramps
– Sets in 4 – 12 hours
– Mainly used for bonding
wood

8. Epoxy resin
 Expensive
 Glue and hardener – 2 part
 Very strong glue
 Bonds different materials
 Quick setting

9. Impact/contact glue
 Used for veneering
 Solvent-based
 Harmful if inhaled
 Strong smell
 Avoid skin contact

10. Using contact glue
 Fixing veneer or laminate to wooden base

11. Superglue
 Very strong bond
 Quick-setting
 Expensive – only for small jobs
 Water-resistant glue
 Bonds many different materials
 Avoid skin contact – harmful

12. Hot melt glue
 Glue sticks are melted in
the hot gun
 Hot liquid glue is squeezed
out with the trigger
 Glue sets quickly

13. Applying glue
 Methods

14. Assembly
 Fit joints without glue and
check
 Apply glue to pieces
 Assemble joints carefully
 Cramp pieces lightly and
firmly
 Wipe off all excess glue with
a clean damp cloth
 Check for square

15. Quiz

16.  What do the letters PVA stand for?
– PolyVinyl Acetate

17.  Name the tool and state its use
• Hot melt glue gun
− An electrically heated gun
used for heating and
applying hot melt glue

18.  Which glue might be used to bond two metals together?
– Epoxy resin glue
– Superglue

19.  Where might you use animal glue?
• Scotch/animal/pearl glue
− Usually used for veneering

20.  Suggest a suitable adhesive to be used when forming the
laminated piece of this project
– PVA glue
– Casein glue

21.  Suggest a suitable adhesive for bonding the veneer to
the base
 A suitable glue might be
– Contact glue
– Scotch/animal glue