Metal Fitting - Sealing Surfaces; Accessory Replacement; Defect Repairs Of Fuel Cell - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
9-62. METAL FITTING - SEALING SURFACES.
a. Rub off roughness of affected area with a fine file or fine emery cloth. Treat reworked area.
b. Clean metal surface using a clean cloth dipped in Methyl Ethyl Ketone. Moisten cleaned surface with
clean cloth dipped in water. Apply alodine 1200 solution, undiluted, to the affected area with a small nylon
brush. Allow solution to dry until a light golden color appears. When coating has been formed, remove excess
solution by wiping with a clean water-moistened cloth Allow coating to dry.
WARNING
Do not allow solution to come in contact with hands, eyes or
clothing.
9-63. ACCESSORY REPLACEMENT.
a. Obtain cured repair accessory from cell manufacturer.
b. Mark location of old accessory and preserve markings for guide lines to locate new part.
c. Remove old accessory by gradually loosening an edge with a blunt probe-like instrument
d. When a loose edge is created, grasp accessory by loose edge with pliers and gently pull accessory off
cell wall. Be careful not to pull cell lap open while peeling accessory off. Pull from blind side of a cell lap
toward the exposed edge.
e. Buff the cell surface under accessory with emery cloth to smooth roughness and prepare for cement
NOTE
Removal of old accessory will probably leave an uneven cavity
and surface.
f. Prepare replacement accessory by buffing and washing contact surface. Also wash cell surface (see
repair patch).
g. Apply mixed 80C27 repair cement to both surfaces being sure to level cavity left by removal of old
accessory.
h. Roll new accessory into place as with a repair patch and place suitable padded plates in position to
insure adequate pressure when clamped. Use cellophane separator to prevent cement sticking in the wrong
place.
i. Cure as with repair patch either cure method.
9-64. DEFECT REPAIRS OF FUEL CELL.
a. Blisters: Remove loose material by trimming. Apply an outside and inside repair patch.
b. Holes, Punctures, Cuts, Tears and Deep Abraded Areas: Trim away any ragged material and apply
an outside and inside repair patch.
c. Loose Seams: Buff loose edge and contact surface with emery cloth. Wash three times with
Methyl Ethyl Ketone. Apply 80C27 mixed cement two coats as with repair patch. Clamp and cure. Either
method may be used. See repair patch. Loose seams may be trimmed if minimum lap remains.d. L o o s e
Fitting Flange - Inside: Buff edge of flange and contact surface under flange. Apply 30C27 mixed repair
cement, cellophane, padded plates and clamp. Follow procedure as outlined for repair patch, except for patch
itself.
e. Looseness Against Metal: Prepare metal as per metal fitting - sealing surfaces. Apply 80C27
mixed cement and cure.
Revised: 3/31/94
FUEL SYSTEM
2Lll