TM55-1500-345-23
(3) Catalytic action begins immediately
Use with adequate ventilation.
on mixing. An eight hour pot life can be an-
Avoid prolonged breathing of vapors.
Avoid prolonged or repeated contact
ticipated after mixing. Ideally, mixed paint should
with skin.
be used in six hours, to assure the capability for
complete system purging and cleaning to preclud-
Failure to observe these precautions can result in
ed equipment damage.
serious injury or systemic poisoning of personnel.
(4) Assure complete mixing when
NOTE
manaul mixing is used.
The wrong thinner may destroy certain
(5) To avoid the possibility of incom-
characteristics of a coating material
patibility of materials under the same specifica-
w i t h o u t immediately giving visual
tion but of different manufacturers, such
evidence in the wet state.
materials shall not be mixed. Primers and top-
Reduced material which has increased in viscosit-
coats from different manufacturers, under the
ty due to evaporation will require corrective addi-
same specification, will not be mixed, but may be
tions. However, some coating materials which
applied separately to areas which are to be over-
undergo chemical processes, such as polymeriza-
coated. Every effort shall be made, however, to
tion to create a film, cannot be thinned beyond a
assure that an entire topcoat is restricted to the
certain point and remain useable; nor can they be
product of a single manufacturer and, where
brought back to the correct viscosity by thinning
possible, to the same batch in order to maintain
after the chemical action has progressed beyond
uniformity of color, finish, etc.
a critical point. This is the case with epoxy and
polyurethane.
(6) Application and mixing equipment
must be thoroughly purged and cleaned after use.
Thinning shall be controlled by weight,
b.
volume or viscosity measurement to obtain and
maintain proper and uniform consistency. If there
is no specification covering the material, thin ac-
Mixing should always be done in areas
cording to manufacturer's instructions.
that are well ventilated and away from
any source of open flame.
NOTE
Do not mix materials of the same
specification but supplied by different
THINNING.
manufacturers during application. This
When thinning is necessary, always add
a.
will avoid problems of incompatibility in
thinner to the coating material. Adding coating
the liquid and curing phases.
material to thinner may result in an irreversible
c.
Strain all material to be used in spray
separation or degradation of some of the coating
equipment through clean 60-90 mesh metal
ingredients. Thinner should be added slowly with
strainers in accordance with paint or equipment
continual stirring to obtain complete mixing. For
manufacturers' instructions.
all thinning, use only thinners authorized in ap-
plicable instructions in this technical bulletin or
3-9. APPLICATION EQUIPMENT.
pertinent specifications or, in the absence of
these instructions, those recommended by the
a.
Application Systems. The application
manufacturer. MEK can be used in cold weather.
equipment plays a key role in the overall success
Other thinners may be needed in hot weather.
of painting aircraft and aircraft components. Se-
lection of application systems and care thereafter
are essential considerations in the painting pro-
cess, whether the system is an automated (robo-
METHYL ETHYL KETONE
tics) or a manual type. No description or details
Keep away from heat and open flame.
are provided herein because of the wide variances
Keep container closed.
