Cessna 188 Series Service Manual page 413

MODEL 188-& T188 SERIES SERVICE MANUAL
appropriate activator to the base with vig- b. Thin paint with T-7945 thinner to spray viscosity
orous stirring. Thinners shall be added (approximately one to one).
after base and activator have been mixed
c. Inspect for overspray and apply "burndown",
in the proper ratio.
T-7945 thinner, to any area showing overspray.
When an induction time is noted the mixed 18-9. MIXTURE AND APPLICATION OF CESSNA
material must be allowed to stand for a EPOXY COLOR (5400 Series.)
minimum of the time indicated before
a. Thoroughly stir and mix in original container
spraying. Failure to comply with this re-
to make sure all pigments are in solution.
quirement can cause the finish to fail in b.
Mix required amount of epoxy with T-6487 ad-
later service.
duct. Ratio is one part paint to one part T-6487 ad-
duct.
Pot lifes indicated are at 75°F. higher
temperatures will shorten the pot life. Do 18-10.
MIXTURE AND APPLICATION OF POLY-
not use any material that shows any in- URETHANE COLOR.
dication of premature gelation (lumps, a. Thoroughly stir and mix in original container
skins, markedly increased viscosity, ect.) to make sure all pigments are in solution.
even if the pot life has not expired b.
Mix required amount of 643-6-20 urethane with
X-310A Converter. Ratio is three parts paint to one
18-6. TOUCH UP OF URETHANE FINISHES TO
part X-310A converter. For Jet Glo Urethane Colors
BARE METAL. follow instructions in paragraph 18-5.
a.
Clean all surfaces to be finished with Naphtha.
Saturate a clean lint free cloth in Naphtha and wring 18-11.
PRIMING OF WELDED TUBULAR STEEL
out so no thinner is dripping from the cloth. Wipe STRUCTURE.
The welded tubular steel section of
the aircraft surface using the Naphtha saturated the aircraft is a sealed, air-tight unit, protected
cloth and immediatly following, wipe the surface with one coat of epoxy primer. After a welded re-
with a dry, lint free cloth,
pair has been made on any part of this structure, the
repair section shall be primed per paragraph 18-3.
NOTE
This also applies to any welded or brazed parts of
the aircraft.
It is important that the Naphtha is wiped
before it evaporates.
Change cloths often 18-12.
PRIMING OF TUBULAR STEEL COMPO-
so the aircraft surface is thoroughly clean- NETS.
Steel tubing parts which are not welded
ed and the surface is not contaminated
shut and cannot be sprayed on the inside shall be
from the use of a dirty rag. Always use
dipped in Red Iron Oxide Primer, and then sprayed
clean Naphtha for the final cleaning. Be
on the outside with epoxy primer per paragraph 18-3.
sure the Naphtha is disposed of when con- An example would be the flap control lever.
taminated.
18-13.
PRIMING OF ENGINE MOUNT. The engine
18-7. TOUCH UP PAINTING OF URETHANE
mount shall be primed with high temperature, Zinc
FINISHES. Rich primer.
a.
Because urethane finishes cannot be burnt in,
they should be applied in sections when being
18-14. PRIMING OF OPEN-END TUBING. If a re-
touched up. All sections should be marked off to pair necessitates the replacement of an open-end
skin laps, edges, or strip lines. The defect in the
steel tubing where barrel nuts are employed, the
section should be removed by sanding with 320
tubing shall be oiled on the inside. After installation
sanding paper. If possible, avoid sanding through
of the nut, seal the open end of the tube with Prets-
the primer to bare metal. If the defect is such that
tite 579.6 sealer (Presstite Engineering Company),
a surfacer is needed to repair the defect, an epoxy
then brush epoxy primer on the seal and tube.
surfacer is recommended.
b.
Minor defects to bare metal one (1) square inch 18-15.
PRIMING OF DETAIL PARTS. All alumi-
and larger should be repaired with wash primer,
num and alumunized steel detail parts shall receive
epoxy primer and urethane topcoat.
one coat of wash primer per paragraph 18-2, and
c. After the defect has been removed and the epoxy
one coat of epoxy primer per paragraph 18-3 before
surfacer has sufficiently cured, scuff sand the entire
assembly.
surface of the section to break the surface glase of
the finish. All surfaces to be painted should be tack- 18-16. PRIMING OF ASSEMBLIES.
All assemblies
ed off prior to application of the urethane finish. The
or sub-assemblies of metal shall receive a second
urethane finish should be applied in two or three wet coat of epoxy primer on all surfaces not exposed on
uniform coats for best results,
the exterior of the aircraft. This coat shall cover all
bare rivets, fasteners and any areas which may have
18-8.
MIXTURE AND APPLICATION OF CESSNA
been scratched or chipped during assembly.
ACRYLIC COLOR (Dupont Lucite Acrylic Lacquer.)
a.
Thoroughly stir (Dupont Lucite Acrylic Lac-
quer) to make sure all pigments are in solution.
Revision 1 18-3