THRUSH AIRCRAFT, INC – MODEL S2R-R1340
AIRCRAFT MAINTENANCE MANUAL
Effective: 01/01/08
9-3
Figure 9-1: 400 Gallon Hopper
HOPPER REPAIR
Ref. Figure 9-2
Hopper repairs should be accomplished
as follows:
A. Fiberglass surfaces must be clean,
dry and free of oil, wax or other
foreign matter. If chemical erosion is
evident, sand rough areas and wash
with any good domestic detergent.
Rinse with clean water. Sand all
surfaces that are to receive a
polyester coating. Use Ashland
Specialty Chemical Company’s 7241
T15 AROPOL™ polyester resin or
equivalent for the hopper repair.
B. If damage consists only of surface
cracks, excessive abrasion or
chemical erosion, sand all affected
surfaces smooth. Extend the
prepared surface six inches beyond
the damaged area.
C. If damage consists of cracks or holes
extending completely through the
wall, sand the surfaces on both sides
deep enough to expose the first layer
of cloth.
D. Surface damage requires repairs
only to the eroded or cracked side.
Damage extending through the wall
requires repairs to both the inner and
outer surfaces of the hopper. The
number of layers in either case
should equal the original basic wall
thickness. (Figure 9-1) Highly
stressed areas, such as attach
points, require an extra layer of cloth
and mat on each side, in addition to
the basic wall thickness.
E.
Curing temperature is 70
°
F
minimum. Higher temperatures
