TO 35-1-3 - Robins Air Force Base

TO 35-1-3
2.2.2.2 To scuff sand a composite surface for overcoating
only use medium grade (Grade C) abrasive mats (A-A-58054)
without powered tools for scuff sanding of painted composite
surfaces. Fine (Grade B) or very fine (Grade A) abrasive mats
may be used with an orbital sander. The abrasive mat can be
wet with fresh water, or diluted cleaning compounds listed in
Table 2-2 for light soils, to prevent clogging the pad.
2.2.3 Coating Removal on Metallic Surfaces. For areas of
several square inches, paint may be removed using abrasive
mats or flap brushes, taking care not to remove underlying
metal. Chemical paint removal, may be used for areas larger
than several square inches. Plastic media blasting or medium
pressure water blasting, may be used at organizational levels
of maintenance activities and depots to remove paint on equipment
with panel skins thicker than 0.0625 inches (16 gauge).
2.2.4 Grinding. Grinding is normally accomplished with
motorized grinding equipment and rubberized abrasive
wheels, discs or abrasive belts. Grinding is normally used to
remove heavy corrosion by wearing the corrosion away. Care
should be taken with this corrosion removal process as sound
metal is also removed with the corrosion product. The basic
steps in grinding are:
2.2.4.1 Protect adjacent components from scale, chips, and
corrosion products.
2.2.4.2 If grease or oil is present, clean areas with the appropriate
cleaner(s) listed in this TO prior to mechanical removal
operations. Ensure all oil and grease residues are removed
before proceeding.
2.2.4.3 Remove paint and corrosion until a corrosion-free
surface is reached. Continue grinding to remove coarse irregularities.
Use fine abrasive paper to polish the surface to the
desired finish.
2.2.4.4 Immediately apply the final protective paint or other
corrosion preventive finish.
2.2.5 Wire Brushing.
The use of goggles or face shield is mandatory when
using motor driven wire brushes since corrosion particles
can break loose and fly off. Conduct all painting
operations only in an approved spray booth
equipped with adequate ventilation and exhaust.
Do not use carbon steel or copper wire brushes on
aluminum surfaces. Carbon steel or copper particles
may become embedded in the aluminum causing galvanic
corrosion to occur.
Wire brushing is a mechanical cleaning operation usually
accomplished with a hand wire brush or a wire brush mounted
on a motor driven wheel. By using different types of brushes,
and various kinds, length, and gages of wire, a wide, range of
mechanical cleaning actions are possible. Wire brushing is
used to remove heavy corrosion and imbedded paint or dirt. A
typical wire brushing procedure follows:
2.2.5.1 Protect adjacent components from scale, chips, and
corrosion products.
2.2.5.2 If grease or oil is present, clean areas with the appropriate
cleaner(s) listed in this TO prior to wire brushing operations.
Ensure all oil and grease residues are removed before
proceeding.
2.2.5.3 Remove loose corrosion with a hand scraper or pneumatic
tools.
2.2.5.4 Wire brush area to a sound metal subsurface, ensuring
all of the corrosion deposits are removed from the corrosion
pits.
2.2.5.5 After mechanical cleaning and rework has been completed,
a final surface treatment and/or protective paint finish,
as listed in this TO, shall be applied as soon as possible.
2.2.6 High-Pressure Water (HPW) Paint Removal
Method.
HPW paint removal system can cause severe damage
to equipment and injury of personnel if instructions
are not followed properly.
High-pressure water (40,000 PSI) paint removal is authorized
for use at depot and field-level operations subject to meeting
all personnel training, safety, and technical data requirements.
HPW equipment is an excellent method for paint removal
from support equipment. The HPW system can be used with
or without blast abrasive such as bicarbonate of soda. These
instructions are not intended to be all-inclusive, but are general
guidelines to be used in conjunction with applicable system
specific equipment manuals and/or a definitive process
order.
Change 4 2-17