Hopper Repair; Hopper Gate Box Removal - Thrush Aircraft S2RHG-T65 TURBO THRUSH Maintenance Manual

THRUSH AIRCRAFT, INC – MODEL S2RHG-T65 TURBO THRUSH
Hopper repair may 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.
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 accelerate curing. A
maximum of 150°F for four hours is recommended followed by ten or more hours
at 70°F.
F. Brush the resin generously over the entire area.
fiberglass cloth and mat.
approximately one inch. After each layer is in place, use a squeegee and/or roller
to remove excess resin and air voids.
Remove the aircraft skins to gain access to hopper gatebox bolts and nuts. Disconnect
dump fork, spray tube, adapter box and vent, emergency shut off cable and spray pump.
Remove the nuts and bolts and pry off adaptor box.
If bolts do not drive out easily, turn bolts to break glue, and
then drive bolts out.
Clean off all old gasket material by scraping, being cautious not to gouge mating
surfaces.
Effective: 05/05/04
AIRCRAFT MAINTENANCE MANUAL

HOPPER REPAIR

(See Figure 9-1)
Use Ashland Specialty Chemical Company's 7241 T15
Each layer should overlap the preceding layer

HOPPER GATE BOX REMOVAL

(See Figure 9-4)
** CAUTION **
Apply alternate layers of
9-3