Technical data

causing contamination or damage to equipment, sys-
tems, or structure. All surfaces where tape is to be
applied shall be wiped down with isopropyl alcohol,
TT-I-735 or acetone, O-A51/ASTM D 329. The solvent
used during the wipe down operation shall not be
allowed to evaporate from the surface, but shall be
wiped from the surface with a dry, clean cloth. Masking
shall be accomplished according to instructions in Para-
graph 2.3 step c and step d of this technical order and the
applicable system-peculiar aircraft or equipment techni-
cal order for the item being stripped, such as the aircraft
system-peculiar -23 corrosion manual or the definitive
process order. In addition to masking and sealing such
areas as fiberglass components, windows, radomes, and
composite structures, drain holes shall be plugged prior
to stripping.
c. Areas which are covered by the barrier tape may be
hand stripped with an environmentally compliant
chemical remover prior to masking for the complete
paint removal operation provided the procedures in this
technical order are strictly followed. Narrow seams
around emergency doors, hatches, entry doors, and other
doors on the aircraft shall be protected from the blast
stream.
2.12.2 Paint Removal Operations. All MPW paint
removal shall conform to the following parameters:
• Bicarbonate of soda blast media shall not
exceed one half pound per minute on the
exterior of any aircraft.
• It is very important to prevent intrusion of the
bicarbonate of soda blast media in areas where
it can become entrapped in the aircraft struc-
ture. It may become corrosive if left within the
aircraft structure. A thorough inspection for
media intrusion shall be performed and a
thorough rinsing with hot water after blasting
shall be accomplished to prevent media from
being retained in the aircraft.
a. The MPW equipment shall have the following operating
parameters: water pressure of 15,000 PSI; water flow
rate of 3 GPM, bicarbonate of soda blast media flow rate
1/4 to 1/2 lb per minute.
b. The nozzle stand-off distance shall be within the range
of 2 to 4 inches from the tip of the nozzle to the working
surface.
c. The angle of incidence between the nozzle and the work
surface shall be within the range of 40 to 60 degrees
(measured from the surface being stripped).
d. In order to limit the amount of time the medium pressure
water and abrasive strikes or hits any given surface
(dwell time) and prevent possible damage, the nozzle
shall be moved across the surface at a minimum rate of
4 inches every second.
2.12.3 Post-Paint Removal Cleaning. Proceed as fol-
lows.
a. When the finish system has been completely removed
by the MPW method, all surfaces of the aircraft,
equipment or component shall be rinsed with hot water
(not to exceed 140° F) to remove all media residue.
b. Remove masking and sealing materials and, if neces-
sary, hand clean protected areas. Allow entire area to
thoroughly dry. Open and flush all covers and/or crev-
ices to eliminate media residue. The aircraft, equipment,
or component shall be thoroughly washed in accordance
with TO 1-1-691.
2.12.4 Operational Safety Requirements. The fol-
lowing is required for safety.
a. All sources of ignition shall be kept a minimum of 50
feet away from the area when MPW paint removal is in
progress.
b. All MPW equipment, work stands, and the aircraft,
equipment, or components being stripped shall be elec-
trically grounded per TO 00-25-172 and the applicable
aircraft or equipment manual during the entire paint
removal operation.
c. All power shall be removed from the aircraft or equip-
ment while MPW paint removal is in progress.
d. The facility used for MPW paint removal shall have
adequate air flow/ventilation. The Base Bioenvironmen-
tal Engineer shall be consulted for proper ventilation
requirements.
e. Personnel involved in MPW paint removal shall wear
ear plugs, ear muffs, goggles, or full face shield,
wet-weather suit, water-resistant hoods, chemical-
resistant boots, and shin and instep guard assemblies.
The shin and instep guard assembly shall be puncture
resistantaluminumwitha5inchwideby6inchlong
instep section attached by a hinge assembly to a shin
section of at least 20 inches in length. Ellwood Safety
Appliance Co. Model No. 3235P is one product that
meets these requirements. All personnel entering the
removal area while MPW stripping is in progress, even
though not involved in the operation, shall also comply
with these personnel protection requirements. The local
base Bioenvironmental Engineer shall define the MPW
paint removal area when the MPW equipment is located
within a larger facility and is not segregated from other
TO 1-1-8
2-26