(19) Inspect the edge seal application for any small air bubbles and if any are found, they can be
relieved by pricking with a hypodermic needle.
(20) The rotor blade is ready to return to service after the sealant is well cured, and the 3M 8663
polyurethane protective tape has had time to reach a acceptable level of adhesion. This is achieved
after 24 hours at 72 degrees.
d. Tail Rotor Agcoat Coating Application.
TASK L-100 polyurethane pain may be used in place of agcoat. TASK
L-100 may also be used to repair agcoat.
(1) Cleaning. Clean area shown in figure 3-54 with cheesecloth or machinery towel dampened
with MEK, isopropyl alcohol or denatured alcohol.
Some rotor blades may be painted with acrylic lacquer, and MEK can
adversely affect this pain and the subsequent quality of the erosion
protection. In this case, MEK should not be used as a cleaning agent.
(2) Masking. Mask off area for polyurethane coating with Tuck tape as shown in figure 3-54.
Surface preparation and cleaning are the most important steps
to insure proper adhesion.
(3) Surface Preparation. Scuff the masked off area with 120 grit sandpaper. Only sand in a
(4) Cleaning. Wipe the masked area several times with cheesecloth or machinery towel
dampened with MEK.
(5) Mix Primer. Stir Part A of primer before using. Mix equal amounts (4 oz of each) of AGC
1201-7 primer Parts A and B in a beaker and stir well. Close can and bottle after pouring out required
Consult U.S. Army Environmental Hygiene Agency (U.S. AEHA) Technical
Guide 144 Guidelines for Controlling Health Hazards in Paint Operations
and the Material Safety Data Sheet (MSDS) for guidance. Use safety glasses,
gloves, and disposable (Tyvek) coveralls. Avoid skin contact. Always apply
coatings so that any spray or vapors are directed away from breathing zone
individuals. Use respirator protection components, table 3-32.
(6) Primer Application. Brush the primer on the blade in the area shown in figure 3-54 where the
coating will be applied. Allow the primer to dry a least one hour at 70 degrees F or above. Do not
handle the primed surface. If the primer surface becomes contaminated, lightly wipe it with denatured