5-10. Wall and Ceiling Panels (cont).
Drill rivet holes in panel face sheet, using holes drilled in doubler as a template. Use drill and pin as a
stop by placing drill inside pin and setting drill in chuck so that 7/16 to 9/16 inch of drill is exposed when
pin is against chuck jaws. Temporarily insert a rivet in each hole as it is drilled to keep patch and
doubler from moving.
Remove doubler and patch. Remove all metal chips and remove burrs from drilled holes.
When machining foam core, be careful not to crush foam, since this results in water
absorption. Do not use a plane to machine foam.
Cut section of new foam core material to fit snugly in core cavity. Core material must be flush with inside
of both panel faces when installed. Use a single piece of foam.
Prepare bonding surfaces of face sheet, patch and doubler for bonding by sanding until oxide film is
removed and bright surface is exposed.
Wipe surfaces with clean cloth soaked in solvent. Immediately wipe solvent from surface with clean
cloth. Wear gloves to avoid contaminating surfaces with dirt, oil or fingerprints.
Prepare adhesive by mixing base material and hardener in accordance with manufacturers instructions.
Use materials within one year from date of manufacture.
Apply adhesive liberally to all surfaces of new core material and cavity and position core material in
Apply a thin, even layer of adhesive to bonding surfaces of face sheet, patch and doubler. Position
patch in place on doubler with sheet fasteners.
When repairing an external face sheet, before installing rivets, inject sealer into drilled
holes to prevent moisture from entering panels.
Rivet patch to doubler and doubler to face sheet. (Refer to paragraph 3-9.a for rivet installation
Wipe excess adhesive from outer surfaces of repaired area. Do not use solvent to remove adhesive.
Allow adhesive to dry.
Coat edges of doubler and rivet heads with sealer,
Touch up with paint as required (para 5-5).