TM-1-1500-344-23-2
AIRCRAFT VOLUME II
TECHNICAL MANUAL; CLEANING AND CORROSION CONTROL
APRIL 2009
TM-1-1500-344-23-2 - Page 102 of 240
5-4
NAVAIR 01-1A-509-2
TM 1-1500-344-23-2
15 April 2009
Coating, Chemical Conversion
7
MIL-DTL-81706
b. Immediately following cleaning, use the TNP pen
to apply a chemical conversion coating solution in
overlapping parallel strokes (see Figure 5-3). Do not
over apply the solution or allow puddles, drips, or runs
to form.
c. Apply one coat of solution and allow coating to dry
for 5-10 minutes.
CAUTION
The newly formed conversion coating is soft
and can be easily damaged. Do not disturb the
coated surface until coating is completely dry.
d. The treated surface does not require rinsing or
wiping-off, and can be air or forced dried with hot air.
Maintain drying temperatures below 140
°
F to avoid
compromising the integrity of the film. Minimum dry time
is one hour. Once completely dried, the coating is ready
for subsequent priming and/or painting.
e. If bare surface areas still exist, repeat paragraphs
b through d.
f. If treated surface does not turn to an iridescent
yellow color shortly following application, re-clean
surface and re-apply (paragraphs a through d).
5-5.6. POWDERY CONVERSION COATING. Allowing
the chemical conversion coating to dwell too long on the
aluminum surface can result in a powdery coated surface.
Aluminum prepaint treatments shall be rinsed
immediately after the allotted pretreatment time. A
brownish color, or dry/matte finish indicates too long a
dwell time and produces a powdery coating. This will not
provide a good surface to which the paint system can
adhere. If a powdery coating is formed, clean the
surface in accordance with paragraph 5-2 and reapply
the solution with a shorter pretreatment time.
5-6. AMS-M-3171 CHEMICAL CONVERSION
COATING FOR MAGNESIUM ALLOYS.
CAUTION
Aluminum conversion coating solution (MIL-
DTL-81706 Type I) is not authorized for treating
magnesium surfaces.
5-6.1. AMS-M-3171 TYPE VI. This material, also known
as Dow #19, is a brush-on chemical surface treatment
for magnesium alloys that provides corrosion protection
and improved paint adhesion. This material is primarily
used to touch-up and repair small areas on magnesium
parts such as transmission housings and gearboxes. It
is available in ready-to-use plastic bottle kits (see
Figure 5-4). Each kit contains an 8 ounce bottle of
premixed magnesium surface treatment solution, two
250 ml polyethylene beakers for dispensing material to
prevent contamination of the 8 ounce
bottle, a 16 ounce
trigger spray bottle for water rinsing, and two reusable
nylon brushes. If the premixed AMS-M-3171 Type VI
solution is not readily available, the solution may be
prepared using the mixing instructions provided below.
Figure 5-3. Application of TNP Pen on
Aluminum Substrate
Figure 5-4.Magnesium Treatment Kit
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