Cessna 172 Maintenance Manual page 53

Preparing Riveted Aluminum Structure For Repair
1.
A. To prepare an area for repair, examine and classify the damage. Make a thorough check before
beginning repairs. In some cases, a damaged part may be classified as needing replacement;
however, after removal, closer inspection indicates the part may be repaired.
(1) Remove all ragged edges, dents, tears, cracks, punctures, and similar damages.
(2) Stop-drill all cracks using a No. 30 (0.128 inch) drill.
(3) Leave edges, after removal of damaged area, parallel to any square or rectangular edges of the
unit.
(4) Round all corners
Smooth out abrasions and dents
(5)
(6) Deburr all edges of repair and ensure that no nicks or scratches remain
(7) Brush all aluminum parts having rough edges with a solution of Iridite or alodine mixed in a ratio
of one ounce of Iridite or alodine to one gallon of water, and rinse thoroughly.
(8) To restore original paint and corrosion protectant properties to factory standards, refer to
appropriate Maintenance Manual, Chapter 20, Exterior Finish - Cleaning/Painting for refinishing
procedures and required materials.
NOTE:
CESSNA AIRCRAFT COMPANY
SINGLE ENGINE
STRUCTURAL REPAIR MANUAL
RIVETED ALUMINUM STRUCTURE REPAIR
Damage adjacent to a previous repair requires removal of the old repair and inclusion
of the entire area in the new repair.
© Cessna Aircraft Company
51-71-00
Page 801
Jun 1/2005