Cessna 182 1978 - Page 29

MODEL
182
& T182
SERIES
SERVICE
MANUAL
2 Testing
of Overaged
Adhesives
and
shelf life extension
shall
be properly
mixed
using the
Cements
correct materials,
procedures
and equipment.
3. Overaged
premixed
frozen
sealants,
along
Sealants
which
show conclusive
evidence
of
Overaged
adhesives
and cements
are those
separation,
discoloration
and/or gelling
prior
to the
that
have exceeded
their
original
shelf life
addition of
a thinner
or curing
agent shall
be
and must
be tested
prior to use
and/or given
discarded.
When in doubt
of the
sealant quality,
the
extended
shelf life.
overaged
sealant
should be
compared
with
the same
type of sealant,
under
six months
old, which
is known
(a)
Class
I Epoxy
Adhesive
- Examine
both
to be
satisfactory.
components
to
ensure that
they are
still workable.
4. The
mixed sealants
may
be tested
by placing
Check
for gelling
and/or
contamination
Stir
a
small amount
of sealant
(smaple buttons)
on a
sheet
components
and
mix a small
amount
of adhesive.
of paper.
After
the sample
buttons
have
cured, they
Verify that
adhesive
sets up and
hardens
should
be cut in
half and examined.
The
sealant
(b)
Class
II,
III and IV
Rubber
and
Resin
should
show
no
signs of
spots
or streaks
of unmixed
Base
Adhesives
-
Open containers
and check
for
base
compound
or curing
agent.
However,
sample
gelling
and/or
contamination.
Check
for spreading
and buttons
containing
spots,
streaks,
discoloration
and/or
drying.
variations
in uniformity
of
color are
acceptable
if these
(c)
Class
V Silicone
Rubber
Adhesives
-
spots,
streaks,
etc.,
are tack
free
upon inspection.
All
Examine
adhesive
for hardness.
If adhesive
is still
soft
mixed
sealant
should
be as
void free
as possible.
and can
be spread,
it is
acceptable.
Verify
that
5.
Contaminated
sealant,
premixed
sealant
adhesive
will harden.
that have
been thawed
and
refrozen
shall
be
(d)
Class VI
Solvent
Bonding
Solvents-
discarded.
Check
for
signs
of apparent
contamination.
Solvents
6. Type
1, Class
A sealants
should
be
checked
should
be clean
and clear
with
no signs of
cloudiness.
for
appearance,
application
time,
tack-free
time,
cure
(e)
Class
VII
Cyanoacrylic
Base Adhesives
time,
and
adhesion.
- Verify
that product
is still
liquid with
no visible
signs
7. Type
I, Class B
sealants
should be
checked
of
contamination.
for appearance,
applicatiion
time, cure
time, tack-free
(
Class
VIII Pressure
Sensitive
Materials
time,
and adhesion.
In addition,
Class
B-2 and
B-4
- Open
containers
and inspect
for
hardening,
gelling
sealants
should
be checked
for
initial
flow.
amount
of adhesive.
Verify
that adhesive
sets up
for
appearance,
application
time,
cure
time
and
properly
adhesion.
In
addition, Class
C sealants
should
be
(g) Class
X Acrylic
Adhesives-
Inspect base
tested
to determine
that they
ARE NOT
at a
tackfree
material
to ensure
that
it is still
liquid.
Mix
a small
condition
at the
end of their
rated
work
life (squeeze
amount
of the
components
and verify
that
it sets
up
out
life).
properly.
9. Type
II sealants
should
be
checked
for
3.
In general,
if
these materials
exhibit
normal
appearance,
application
time,
tack-free
time
and cure
physical
properties,
with no signs
of hardening,
time.
gelling or
contamination
and set
up and/or
harden
10.
Type III
sealants should
be easily
thinned
properly
as applicable,
the shelf
life may
be extended
with
MEK,
when difficulty
is
encountered
in thinning
as specified
in
Table 1-7.
the
sealant,
it should
be discarded
e. Testing
of
Overaged
Sealants
11.
Type
IV sealants
should
be
checked
for
appearance,
application
time,
tack-free
time
and cure
NOTE
time.
12.
Type V and
VI sealants
should
be checked
Overaged
sealants
are those
that
have
for appearance,
tack-free
time
and cure
time.
exceeded
their original
shelflife
and
13
Type
VII sealants
should
be checked
for
must
be tested
prior
to use
and/or
given
appearance,
application
time,
tack-free
time
and
cure
extended
shelf life
time
14
Type
VIII
sealants
should
be
checked
for
1. For identification
ofsealants
Classification,
appearance,
application
time, tack-free
time,
cure
refer
to Fuel,
Weather,
Pressure
and High-
time
and adhesion
Adhesion
to aluminum
should
be
Temperature
Sealing
-
Maintenance
Practices.
(peel)
less
than
two-pounds
per
inch of
width.
2 Overaged
sealants
to be
tested for
possible
Revision 2
1-19