Technical data

* = These solvents are composed of a mixture of photochemically reactive hydrocarbons and oxygenated hydro-
carbons and have a maximum vapor pressure of 7 mm Hg at 20° C (3.75 in H2
O
at 68° F). There are no re-
porting requirements or containment controls on the use of these solvents. NOTE: These solvents evaporate
slowly and must be completely dried prior to application of paint.
FL 3 = These solvents are exempt from any reporting and controls under the NESHAP. Not all local state au-
thorities have granted these exemptions.
FL 4 = Alcohol’s are not compatible with polyurethane’s. Make sure they are totally removed before applying
polyurethane’s.
FL 5 = Most vendor’s products which meet specifications are NESHAP compliant, but some are not. Check ven-
dor’s MSDS to determine if composite vapor pressure is 45 mm Hg or less and therefore compliant.
FL 6 = See Glossary for definitions of “Organic Coatings” and “Solvent Resistant Coatings”.
3.1.6 Reactivation of Newly Applied Primer or
Tiecoat. All standard organic coating systems consist of an
approved primer and topcoat or tiecoat and topcoat. In the
application process, many times it is critical that topcoats be
applied to the primer before the primer completely cures.
Specific coating cure times are listed in Chapter 6. When the
cure time is exceeded, the primer or tiecoat must be reacti-
vated to assure adhesion of the topcoat. Reactivation may be
accomplished either through a solvent wipe or by scuff
sanding. Solvent wipe for reactivation is normally allowed
within a specified window during the curing process and is
not effective for fully cured coatings. When solvent wipe is
permitted, wipe the entire aircraft surface with a white
lint-free, cotton cloth (CID A-A-59323) conforming to A-A-
2522, Grade A, color 1 (PN AA 522-A1) or cotton gauze/
cheese cloth conforming to CCC-C-440, Type II or III wetted
with one of the solvents approved for this process in Table
3-2. Ensure surfaces are completely wetted to soften the
coating and promote reaction between the solvents and
binders in the topcoat with the primer or tiecoat for adhesion.
Scuff sanding for reactivation shall be accomplished using
320 or 400 grit sandpaper, A-A-58054, Type I, Class 1, Grade
B abrasive mat, or hook and loop or roloc mounted surface
condition discs “very fine” grade (3M Co.) to reactivate the
primer or tiecoat for adhesion of the topcoat. Surfaces shall
be scuff sanded 100% using procedures in Paragraph 3.1.3
followed by a solvent wipe per Paragraph 3.1.4.
3.1.7 Surface Preparation, Unpainted Surfaces. The
final step in surface preparation for coatings application is the
inspection and treatment of unpainted metal surfaces, i.e.;
areas of peeled or damaged coatings; depainted surfaces; or
new repairs or fabricated components. A thorough inspection
for corrosion shall be conducted over the entire surface to be
painted. All areas requiring mechanical and chemical corro-
sion removal will be identified and marked.
3.1.8 Corrosion Removal, Chemical and Mechani-
cal. All chemical and mechanical corrosion removal re-
quired for treatment of corrosion damage shall be accom-
plished in accordance with the System Specific Corrosion
Control technical Order and TO 1-1-691. All corrosion
removal and treatment shall be accomplished prior to per-
forming prepaint processes in this manual.
NOTE
All work requirements, repairs, mechanical cor-
rosion removal, and sealing requirements (sealant
cured completely) shall be completed, inspected
and have all defects corrected prior to prepaint
cleaning and surface preparation. Failure to com-
ply with the above requirement will cause paint
adhesion problems and severe delays in painting
operations.
3.1.9 Preparation for Prepaint Treatment, Unpainted
Surfaces. Prior to application of corrosion removal com-
pounds on aluminum or magnesium, all surfaces to be treated
shall be thoroughly cleaned of dirt, grease, and contamina-
tion. Immediately prior to prepaint treatment evaluate sur-
faces and clean as follows:
3.1.9.1 Conduct a thorough inspection over the complete
surface to be treated to ensure all foreign matter that may
have been retained in seams, or oily deposits that may have
accumulated during or after cleaning, have been removed.
Also, all corrosion that is to be chemically treated during the
prepaint surface preparation must be identified.
3.1.9.2 All surfaces shall be regarded as dirty even if there
is no visible dirt. Carefully wash the aircraft or surfaces to be
treated per TO 1-1-691 and spot clean using solvent wipe per
Paragraph 3.1.4.
3.1.9.3 Water break tests shall be conducted on represen-
tative areas to be treated immediately prior to application of
corrosion removal prepaint solutions.
3.1.10 Water Break Inspection. The following proce-
dures shall be used to comply with the water break inspec-
tion. A Water Break Free Kit (NSN 6850-01-524-8291) is
available, which contains all the items needed to complete the
test. A mist of distilled or clean tap water is atomized on the
surface to be coated employing any convenient small atom-
izing spray device. If the water gathers into discrete (sepa-
rate) droplets within 25 seconds, that is, if the surface shows
a water break within this time, the surface shall be considered
as failing the test. If the water forms a continuous film by
TO 1-1-8
3-7