Technical data

13773-001
51-30
Page 730 Nov 2000
(3) Filler Thickness Inspection
Filler thickness is verified by inserting the pointed end of the toothpick into uncured filler. The wet
portion of the toothpick is then measured with a vernier caliper. The wet portion of the toothpick
is referred to as the filler thickness.
Note: If multiple layers of filler are used, each layer must be measured. Add the
thickness of each layer together for total filler thickness. Over large areas,
body filler thickness shall not exceed 0.13 inch (3.3 mm) No more than 15%
of the surface may be covered with body filler and no more than 5% of the
surface area shall have filler thicker than 0.10 inch (2.5 mm). Body filler
thickness in small local areas (less the 10 square inches) or at seams and
joints may exceed maximum filler thickness.
(a) Acquire necessary tools, equipment, and supplies.
(b) Push toothpick into uncured body filler until toothpick comes to rest against laminate.
(c) Measure wet portion of toothpick (body filler depth) using a vernier caliper.
Note: If body filler thickness exceeds the aforementioned specification, remove
body filler and repair the area with the proper composite repair procedures.
(Refer to 51-20)
(d) Fill inspection hole with body filler. Allow body filler to fully cure.
D. Sealer
Sealer prevents moisture from effecting the fillers and staining of the topcoat from chemicals released
by the fillers. Sealers should be applied over the final surfacer coat.
(1) Application of Sealer
WARNING:
Aircraft control surface balance is critical to safe flight. If any paint, body
filler, striping, or other material is added to a control surface, the control
must be re-balanced. Mask flight control hinge bushings and bearings prior
to applying surfacer or paint.
CAUTION: Cover any system that may be contaminated by sealer or where extraneous
sealer may cause the system not to operate properly (for example, the flight con-
trol system and the pitot/static system).
Note: When sealer is dry, top coat (paint) as soon as practical. It is not necessary to
abrade sealer prior to application of top coat as long as it is applied within the time
limit specified by the manufacturer.
Description P/N or Spec. Supplier Purpose
Vernier caliper, 6-inch - Any Source Check filler thick-
ness
Toothpick - Any Source Check filler thick-
ness