TM55-1500-345-23
must be curbed. Changing atmospheric condi-
3-12. FILM
THICKNESS
(AIRCRAFT
tions, during operations, may have to be conpen-
SURFACES).
sated for in order to continue applying a uniform
film. Frequent checks with a wet film thickness
Film applied either too thick or too thin
a.
gage, if available, should be made during painting
will have reduced effectiveness in service. (See
to ascertain and control film thickness. Thickness
MIL-C-46168 for recommended film thickness ap-
cannot be gaged accurately without instruments,
plicable to standard coatings for aircraft. Recom-
but, lacking these, the best assurance of consis-
mended minimal dry film thickness is 1.8 roils). At-
tent films is in correct initial adjustment of gun
taining proper coating thickness by spraying is a
and material and the use of good judgement.
matter of technique, plus periodically checking
the work. There is a limit to the thickness that can
be applied at one pass because of possible sagg-
NOTE
ing of the film, and often this must be considered
in obtaining the ultimate desired thickness of all
C a r e should be taken that proper
paints. Also, there is a tendency with coating
measurements are made when extreme.
materials of good hiding power to increase the
Iy rough texture paint is applied, e.g.,
spreading rate as the work progresses and this
MIL-C-46168 aircraft green.
