Cessna 172 Maintenance Manual page 54

1. General
A. The following procedures are for parts which are constructed of epoxy prepreg glass fabric.
2. Tools and Materials
NOTE: Equivalent substitutes may be used for the following:
NAME
Fiberglass
Polyethylene sheet
Adhesive
Adhesive
Adhesive
Methyl Propyl Ketone
Sandpaper
Rubber sheet
3. Repair Of Glass Fabric Parts
A. The procedures listed below are for repairing of glass fabric parts. Refer to Figure 801 for an illustration
of a typical glass fabric repair.
(1) Cut and trim area immediately beyond damage. If parts were painted, remove paint and sand
clean an area at least 1-1/2 inches larger in diameter than the cut out section.
(2) Prepare necessary size and number of patches of glass fabric style No. 181.
WARNING: Always follow manufacturer's mixing instructions carefully to
(3) Mix sufficient amount of resin in accordance with manufacturers instructions.
(4) Ensure that hands are free from oil, grease, and dirt, and apply an even coat of resin on sanded
area.
(5) Impregnate all the glass fabric patches by laying them on a polyethylene sheet and working the
resin through the glass fabric with a small brush.
(6) Place larger patch over cutout area, working out all air bubbles and wrinkles.
(7) If cutout is large enough to cause the patch to sag, place a suitable support behind repair area.
(8) Apply a second patch over the first patch, working out all wrinkles and air bubbles.
(9) After all patches have been applied, brush the area with an even coat of resin and allow to cure.
Curing time is 24 hours at 77°F.
(10) Smooth patched area with 600-grit sandpaper until desired finish is obtained.
(11) Repaint finished area with matching paint. Refer to the applicable Maintenance Manual, Chapter
20, Exterior Finish - Cleaning/Painting for painting procedures.
CESSNA AIRCRAFT COMPANY
SINGLE ENGINE
STRUCTURAL REPAIR MANUAL
GLASS FABRIC REPAIR
NUMBER
181 weight
EA9394
EA9396
Epon 815
Various grits
ensure proper cure and prevent a spontaneous fire.
© Cessna Aircraft Company
MANUFACTURER
Hexcel
Commercially available
Loctite Aerospace
Bay Point, CA 94565
Loctite Aerospace
Loctite Aerospace
Commercially available
Commercially available
Commercially available
USE
Repair composite
structures.
Cover patches while
curing.
Adhesive resin.
Adhesive resin.
Adhesive resin.
Cleaning solvent.
Abrading, smoothing.
Cover patches when
applying pressure.
51-73-00
Page 801
Jun 1/2005