Cut 6 pieces of 4-inch wide polyurethane tape 36 inches long.
Cut 2 pieces of 4-inch wide polyurethane tape 30 inches long.
Cut 2 pieces of 4-inch wide polyurethane tape 6 inches long.
Surface preparation and cleaning are the most important steps to insure proper
(4) Surface Preparation. Scuff the masked off area with 120 grit sandpaper. Only sand in a spanwise direction,
figure 3-1, sheet
of power sander
is permitted for this procedure.
Do not sand the bare metal skin of helicopter rotor blades. Sanding bare metal
skin on helicopter rotor blades reduces the structural integrity and fatigue life of
(5) Cleaning. Wipe the masked area several times with cheesecloth or machinery towel dampened with
isopropyl alcohol or denatured alcohol, then wipe once again with a clean, dry cloth.
Perform Steps (6) trough (9) for one blade at a time.
(6) Application of Adhesive Promoter. Apply a thin coat of No. 86 adhesive promoter to the masked area where
the first 6-inch long piece will cover, as shown in figure 3-21. Allow to dry at least five minutes, but not more than one
hour before applying tape.
(7) Polyurethane Tape Preparation. Apply alignment marks to outside surface of tape at the center. See figure
2. Peel back one
of the center (1-inch wide) backing strips from the
4" wide tape approximately
3 inches. See
(8) Tape Alignment. Align the tape in the position shown in figure 3-21 before pressing to blade.