Characteristics of natural glues
|
Casein
|
Fish
|
Hide
|
Rice & wheat pastes
|
|
| Applications |  tropical
woods;
structural
lamination,
panel and
flush door covering;
may produce
glue lines with a thick appearance.
|
light-duty, wood-to-wood bonding;
natural nonwood
materials (such as cloth, metal and bone) to wood.
|
good combination of versatility, compatibility and strength;
edge- and
face-gluing, assembling joints; veneering, repairing and bonding natural nonwood materials to wood.
also used
for sizing, a wood conditioner and a grain filler.
|
bonding porous, pliant materials (such as paper, cloth and leather) to wood;
commercial
formulas require no cooking and are easy to use. |
| Availability/ using |
requires careful two-step mixing with water.
|
ready to use;
can be coloured
with dyes etc;
refrigerate
to extend shelf life.
|
granules -mix with water and heat to 140°F before use;
ready-to-use
liquid hide glues also available;
add water
if glue thickens;
add urea
or salt to retard gel rate;
can be coloured
with dyes etc.
|
mix with water and cook before use (if required);
add preservative
to prevent mould growth;
can be coloured
with dyes etc. |
| Typical working time
# |
15 to 45 minutes | 15 to 30 minutes | 1 to 10 minutes
|
15 to 20 minutes |
| Clamp time # | 2 to 8 hours | 2 to 4 hours | 10 to 90 minutes
|
3 to 6 hours |
| Cured working properties |
cures hard, sands readily, but dulls cutting tools rapidly;
permanently
stains the surface of high-tannin woods such as oak and mahogany.
|
cures hard;
machines
and sands well;
compatible
with stains and finishes;
reversible
with water. |
Cures very hard;
machines
and sands well. |
Cures soft and flexible;
Easily cut
with hand tools;
compatible
with stains and finishes;
reversible
with water. |
| Cured properties |
excellent strength, rigidity and durability;
highly creep
resistant;
some gap-filling
ability. |
good strength, rigidity and creep resistance;
not as strong
as hide glue. |
excellent strength, rigidity and creep resistance;
thick glue
layers can be brittle. |
not strong enough for most structural wood-to-wood bonding. |
| Long-term properties |
high-grade formulas have good moisture and solvent resistance;
low-grade
formulas have lower moisture resistance;
can be subject
to bacterial and fungal attack unless preservative is added. |
Excellent heat and solvent resistance;
poor water
resistance;
glue layers
desiccate with time and becomes brittle. |
resistant to moderate heat and moisture levels, despite reversibility;
good solvent
resistance and shock resistance;
glue layers
desiccate with time and becomes brittle. |
subject to bacterial and fungal attack unless preservative is added. |
Top