Carrier 69NT40-541-001 Operation And Service page 127

7.24 MAINTENANCE OF PAINTED SURFACES
The refrigeration unit is protected by a special paint system against the corrosive atmosphere in which it normally
operates. However, should the paint system be damaged, the base metal can corrode. In order to protect the refrig-
eration unit from the highly corrosive sea atmosphere, or if the protective paint system is scratched or damaged,
clean area to bare metal using a wire brush, emery paper or equivalent cleaning method. Immediately following
cleaning, spray or brush on zinc-rich primer. After the primer has dried, spray or brush on finish coat of paint to
match original unit color.
7.25 COMPOSITE CONTROL BOX REPAIRS
7.25.1 Introduction
This procedure provides instructions for repair of the Carrier Transicold composite control box. Damage to the control
box may be in the form of a chip or hole, a crack, a damaged thread insert or damage to the door hinge inserts. Gen-
erally, the object of the repair must be to ensure sufficient strength is restored to the damaged area and the repair
must keep the box water tight. Information on repair kits and repair procedures for each type of damage is provided in
the following paragraphs. Ambient temperature must be above 7°5C (45°F) for proper curing of epoxy repairs.
7.25.2 Cracks
Cracks in the control box are repaired using a fiberglass patch over the damaged area. Materials required are
included in the Fiberglass Patch Kit supplied with Crack Repair Kit, Carrier Transicold part number 76-00724-00SV
(see Table 7–2).
a. The surface must be clean and dry. Roughen the surface with sandpaper to ensure a good bond.
b. Cut the fiberglass cloth to allow a 25mm (1-inch) overlap around the area to be repaired.
c. Stretch and position the cloth over the area to be re paired and secure it with masking tape.
d. Make up sufficient epoxy glue to cover the cloth by mixing equal parts of resin and hardener. Saturate the
cloth with the epoxy glue, spreading evenly.
e. Remove the tape and overlap the edge of the cloth approximately 6 to 12 mm (1/4" to 1/2") with glue.
f. Epoxy will dry in 45-60 minutes. When completely cured (12 hours), use sandpaper to smooth edges of the
patch.
7.25.3 Chips And Holes
Chips and holes in the control box are repaired using a piece of aluminum or stainless steel to cover the damaged
area. The material can be cut to suit and riveted in place. An adhesive sealant must be used to make the repair
watertight. The adhesive sealant (Sikaflex 221) is included in Crack Repair Kit Carrier Transicold part number 76-
00724-00SV (see Table
gar-like odor).
a. To make up the patch, cut a piece of aluminum or stainless steel so that it will overlap the damaged area by
at least 40 mm (1 1/2") on all sides.
b. Choose rivet locations and drill the rivet holes in the corresponding locations on the control box and patch
piece.
c. Apply the adhesive sealant around the damaged area to form a seal between the control box and the patch
piece.
d. Rivet the patch piece in place.
e. File smooth any rough edges (including rivets) that may come into contact with wires.
7.25.4 Inserts
The threaded brass inserts that are molded into the control box will need to be replaced if the threads become
stripped, or if the insert becomes loose. The inserts and epoxy are contained in repair kit, Carrier Transicold part
number 76-50084-00 (see
the locations of the various inserts.
An epoxy application gun is also needed, Carrier Transicold part number 07-00391-00.
7–2). Do not use an acetone based silicone sealant (Which can be identified by a vine-
Table 7–3). There are 6 different inserts used in the control box. Refer to
NOTE
7–39
Figure 7.31 for
T-316