TO 1-1-700 - Robins Air Force Base

TO 1-1-700
11.6 3M CO. SCOTCH-BRITE FINISHING FLAP
BRUSHES.
11.8 POWERED WIRE BRUSHES.
Do not use flap brushes down to within two inches of
core (see Figure 11-2). Continued use beyond this
limit may cause gouging due to loss of flexibility of
fiber. When using flap brushes, apply minimal pressure
to the tool so that a minimum amount of metal
will be removed. Excessive pressure on flap brushes
will cause paint at the edge of the area being worked
to melt, gum up, and streak onto the work area. Do
not use on non-metallic surfaces.
11.6.1 Flap Brushes. Flap brushes are made of non-woven,
nylon webbing impregnated with aluminum oxide grit. The
brushes are very effective for removing mild surface corrosion
and prepping surfaces. It can also be used for mechanical
removal and feathering of paint systems. The brushes are comprised
of a series of flaps bonded to a cardboard core and
attached to a mandrel. Each flap impacts the surface as the
brush spins. When used correctly, the brushes will lead to
minimal metal removal. The flap brush and mandrel (refer to
Figure 11-1) shall be assembled so that the arrow painted on
the brush is facing the operator and points in the direction of
rotation (clockwise). To achieve maximum effectiveness, use
at the specified RPM, and do not exceed the maximum RPM
rating specified on the brush to prevent disintegration during
use and either damage to equipment or injury to personnel.
11.6.2 Abrasive Flap Wheels. Abrasive flap wheels come
in various types. One type is made of paper flaps impregnated
with aluminum oxide abrasive and mounted on a spindle (refer
to Figure 11-2). Another type is made from a resin reinforced
nylon mesh impregnated with aluminum oxide abrasive in a
convoluted flap form per A-A-59292, Class 1 or a unitized,
rigid, laminated form per A-A-59292, Class 2, both of which
are mounted on arbors. Depending on grit size, these wheels
can be used to remove medium to severe corrosion from thick
materials, but caution must be used to minimize the amount of
metal removal. For the most effective use of this equipment,
use at the specified RPM and never exceed the maximum
RPM rating specified on the wheel to prevent disintegration of
the wheel during use and either damage to equipment or injury
to personnel.
11.7 ABRASIVE CLOTH AND PAPER.
Aluminum oxide and silicon carbide cloth and paper can be
used with sanders and drill motors by cutting suitable pieces
from stock or using precut discs mounted on pad type holders.
Unless authorized and directed by the cognizant
equipment SPM, rotary wire brushes are not authorized
for corrosion removal on any metals except low
strength carbon steels. They can severely damage
softer metal alloys such as aluminum and magnesium
by leaving deep gouges in them and cause fatigue
problems in high strength steel and aluminum alloys
due to the stress risers created by the deep scratches/
gouges they leave on the surface.
Powered wire brushes are available with various types of wire
(straight, twisted, or crimped), various lengths of wire (short,
medium, or long), and various wire densities (light, medium,
or heavy). Different actions can be obtained by varying wire
type, trim length, and density.
11.9 ROTARY FILES.
Improper use of rotary files can rapidly damage aluminum
structures by creating thin spots that exceed
established damage limits. Their use is authorized
only for removal of severe intergranular exfoliation
corrosion by qualified structural repair technicians.
Do not use rotary files to remove corrosion from installed
fasteners.
Since they provide one of the fastest ways to remove corrosion
and underlying metal, rotary files should only be handled by
an experienced structural repair technician. This tool is a tungsten
carbide cylinder or cone into which cutting edges have
been machined. When installed in the chuck of a pneumatic
drill, rapid metal removal can be achieved.
11.10 3M CO. ROLOC DISC AND RADIAL DISC
ABRASIVES.
These tools are available in various grits and diameters to
cover all corrosion removal requirements from initial grind out
to final finishing/smoothing of the grind-out area. To achieve
maximum effectiveness with these discs, use at the specified
RPM, and never exceed the maximum RPM rating specified
on the disc to prevent disintegration of the disc during use and
either damage to equipment or injury to personnel.
11.10.1 Roloc Discs. Roloc Discs consist of a spindle
that screws into a disc pad that receives a screw on type paper
11-6