TM 1-1520-238-23
2-308
Change 1
2.88.
ROTOR SUPPORT MAST SUPPORT BASE REMOVAL/INSTALLATION – continued
(d) Immediately place impression material into wall cavities of the hole (hardening time is 2 to 3 MIN-
UTES).
(e) Work impression material hard by hand into metal to ensure penetration into any pits (1 MINUTE is
required). Cover a total distance of one half the total internal wall surface area (use centerline as
reference). Use flashlight and mirror to verify.
(2) Circular cavities:
(a) Make an applicator stick from wood 0.75 INCH in diameter by 12.00 INCHES long. Round one end to
0.25 INCH radius.
(b) Use two scoops of red putty with two scoops of white catalyst.
(c) Mix the two components by hand using fingers and roll in palms until a uniform dull red is formed. ONE
MINUTE is required to mix the components.
(d) Form into a 5.25 INCH long roll.
(e) Place impression material on rounded bottom of applicator stick extending on one side, approximately
5.00 INCHES. If compound adheres to applicator stick, apply lubricant to stick. Use petrolatum
(item 138, App F).
(f) Immediately place impression material into wall cavities of the hole (hardening time is 2 to 3 MIN-
UTES). Ensure impression material reaches bottom and runs the entire depth of hole extending
slightly over hole lip. Press impression material hard to ensure penetration into all pits (1 MINUTE is
required). Work to cover half the wall surface and half the bottom of cavity. Use applicator stick as a
rolling pin. Use flashlight and mirror to verify.
(3) Allow impression material to set for 2 MINUTES.
(4) Peel off hardened impression material.
(5) Use a magnifier to verify the deepest impression.
(6) Measure the depth of the depression. Use caliper.
(7) Record pits.
(8) Repeat impression process for each remaining side and bottom of triangular cavities and the other half of
each internal surface and bottom of circular cavities.
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