TO 35-1-3 - Robins Air Force Base
TO 35-1-3 - Robins Air Force Base
TO 35-1-3 - Robins Air Force Base
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<strong>TO</strong> <strong>35</strong>-1-3<br />
with AMS 3367, Class A or B or PR-1773, Class B sealant or<br />
Av-DEC TM HT39<strong>35</strong>-7 or HT3000FR sealant tape in the joints<br />
as specified by the system specific maintenance manual. In<br />
addition to faying surface sealing, fillet seal all interior seams<br />
and all exterior seams (those exposed to the outside environment)<br />
that would allow water intrusion using MIL-PRF-<br />
81733, Type II, Class 1 or 2, Grade A sealant.<br />
NOTE<br />
The following does not apply to parts that are lubricated<br />
in the joint areas immediately before or after<br />
installation, or to close tolerance bolts and parts that<br />
are removed frequently for maintenance requirements.<br />
3.8.3.3.1 Attaching parts, such as nuts (standard, speed, and<br />
self-locking), bushings, spacers, washers, screws (standard<br />
and self-tapping), sleeves for shake-proof fastener studs,<br />
clamps, bolts, etc., do not need to be painted in detail except<br />
when dissimilar metal or wood contact is involved with the<br />
materials being joined or exposure to a corrosive interior environment<br />
or the exterior environment will occur in service.<br />
However, all parts shall be installed wet with sealant. For permanent<br />
installations, use MIL-PRF-81733, Type I or IV, Class<br />
1 or 2, Grade A sealant and coat the entire mating surface of<br />
the parts. For removable installations, use SAE AMS 3367,<br />
Class A or PR-1773, Class B sealant and coat only the lower<br />
side of the heads of screws and bolts with sealant. For removable<br />
installations, do not coat the threads and shanks of screws<br />
and bolts or the holes into which they are inserted because this<br />
will make future removal almost impossible without damaging<br />
the parts. As an alternate for removable installations, the<br />
shanks, threads, and lower side of the heads of standard<br />
screws and bolts may be coated with MIL-PRF-63460, MIL-<br />
PRF-16173, Class II, Grade 3 before they are installed. Close<br />
tolerance bolts and parts shall be coated with corrosion inhibiting,<br />
solid film lubricant. Use MIL-L-23398 or MIL-PRF-<br />
46147 (air curing type) on aluminum parts and on all types of<br />
metallic parts. The solid film lubricant shall be applied and<br />
completely cured prior to assembly. Bolts shall be coated on<br />
shanks and threads only. A thin bead of sealant shall be<br />
applied under the bolt head to impart a wet seal.<br />
3.8.3.3.2 All rivets shall be installed wet with MIL-PRF-<br />
81733, Type I or IV, Class 1 or 2, Grade A sealant. In fuel<br />
contact areas, the exposed rivet head and approximately 1/4-<br />
inch of the adjacent structure shall be brush over coated with<br />
SAE AMS-S-8802 Class A sealant.<br />
3.8.3.3.3 All machine screws, countersunk fasteners, bolts<br />
(head end) and nuts which are used in contact with magnesium<br />
shall be installed with 5056 aluminum alloy washers. These<br />
parts, including the washers, shall be installed wet with MIL-<br />
PRF-81733, Type II, Class 1, Grade A sealant and shall be<br />
completely fillet sealed with the same material after installation.<br />
3.8.3.3.4 Adjustable parts, such as tie rod ends and turnbuckles<br />
shall be installed as follows: (1) If possible, surfaces and<br />
threads shall be lubricated and protected before assembly with<br />
a film of MIL-L-23398 or MIL-PRF-46147 (air curing type)<br />
corrosion inhibiting, solid film lubricant which shall be completely<br />
cured prior to assembly. After installation, apply a thin<br />
coating of MIL-PRF-63460; MIL-PRF-16173, Class II, Grade<br />
3; or MIL-PRF-81309, Type II, water displacing, corrosion<br />
preventive compound (CPC), to all surfaces of these parts. (2)<br />
If solid film lubricants cannot be applied, use a thin coating of<br />
MIL-PRF-63460; MIL-PRF-16173, Class II, Grade 3; or MIL-<br />
PRF-81309, Type II water displacing, corrosion preventive<br />
compound (CPC) after assembly.<br />
3.8.3.3.5 When practical, slip fit parts shall be assembled<br />
with mating surfaces wet with MIL-PRF-81733, Type I or IV,<br />
Class 1 or 2, Grade A sealant. If this process is not practical,<br />
coat the interior diameter (ID) of the holes in the receiving<br />
part, which is normally the larger structure with a corrosion<br />
inhibiting, solid film lubricant conforming to MIL-L-23398 or<br />
MIL-PRF-46147 (air curing types) and the outer diameter<br />
(OD) of the mating part with one conforming to MIL-L-23398<br />
or MIL-PRF-46147 (air curing types). The solid film lubricant<br />
shall be applied and completely cured prior to assembly.<br />
3.8.3.3.6 All cut edges and holes drilled or reworked for<br />
bolts, screws, rivets, studs, and bushings of aluminum alloy<br />
structures or parts shall receive a chemical conversion coating<br />
treatment prior to the installation of the fasteners or bushings<br />
and prior to installing or refinishing the structure or parts.<br />
Apply a conversion coating to aluminum surfaces, using<br />
Touch-N-Prep pen containing Alodine TM 1132. On steel surfaces<br />
use the appropriate primer to coat the cut edges of holes<br />
prior to reinstallation of the parts.<br />
3.8.3.4 Sealant may be applied by brush, spatula, or caulking<br />
gun application.<br />
3.8.3.5 To prevent sealant from contacting adjacent areas<br />
during application and smoothout, outline the areas being<br />
sealed with masking tape (AMS-T-21595, Type I) so that each<br />
tape strip is 1/8 to 1/4 inch from the edge of the seams.<br />
3.8.3.5.1 Apply the sealant between tapes with a nonmetallic<br />
spatula or spreader, brush or caulking gun. Avoid the entrapment<br />
of air. Work sealant into recesses by sliding the edge of<br />
the spatula firmly back over the recesses. Smoothing will be<br />
easier if the nonmetallic spatula is first dipped in water.<br />
3.8.3.5.2 Remove masking tape after the sealant has been<br />
applied and before it begins to set. Cure time will depend upon<br />
the application life of the materials used.<br />
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