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