(h) Fold cell so repair can be completed withoutrepositioning
WARNING: CEMENTS AND SOLVENTS ARE FLAMMABLE. MIX AND APPLY CEMENT IN WELL VENTILATED AREA.
WARNING: REPAIR CEMENT 5923C SHELF LIFE IS ONE YEAR FROM DATE ON CONTAINER. DO NOT USE OUT DATED CEMENT.
NOTE: Mix and apply cement at minimum temperatureof 70°F. Pot life of mixed cement is 20 minutesto one hour.
(i) Mix repair cement 5923C as follows:
(1.) Shake contentsof part 2. (2.) Pour contentsof part 2 into part 1. Stir thoroughly, makingsure entire contents of both containersareare blended completely.
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PIPERAIRCRAFT
PA42-720(Advanced Trainer)
MAINTENANCE MANUAL
A. Storage (continued)
17.Repair Patch (Air Cure Method) (continued)
NOTE:Rapid stirring or shaking will cause air bubbles to form. Air bubbles in cement can result in repair voids, pits, blisters, and leak paths.
(j) Apply one evencoat of 5923C cement on buffed area of cell to within 1/4inch of edge and on buffed side of patch. Allow to dry for 15 minutes.
CAUTION: COVER CEMENT CONTAINER BETWEEN APPLICATIONSTO MAXIMIZE POT LIFE.
(k)
Apply second coatof 5923C repaircementto cell and patch. If cement hasbecometoo thick to brush, mix new batch of cement. [Referto step (i).]
(I)
Allowcementto dry for 5 minutes.
(m)Center repair patch over damaged area. Lay patch carefully by rolling action from center of patchto edges to prevent trappingair. While surface is wet, slide repair patch by hand to improve lap
CAUTION: BE SURE PIECEOF CELLOPHANE IS LARGER THAN CEMENTEDAREA AND REMAINS IN PLACE. ENSURE FILM OBTAINS COMPLETECOVERAGE.
(n)
Tape piece of cellophane over patch.
NOTE: Aluminum plates must be larger than patch.
(o)
Coverone side of aluminum plate with 0.25 inch fabric-backedairfoam(fabric side out). Tape airfoam into place. Ensure airfoam coversedgesof plate for protection.
(p)Cuttwo backup boardslarger than cementedarea and smooth all edges.
CAUTION: ENSURE CELL IS NOT FOLDED BETWEEN PRESSURE PLATE AND BOARDS TO PREVENT PERMANENTCREASE.
CAUTION: ENSURE PATCH DOES NOT MOVE WHEN TIGHTENING CLAMP.
(q)
Fold cell next to patch. Placeplate with airfoamover patch.
(r)
Secureassemblyin place with C clamp. Wipe off any excess cementthat flows from pressure plates.
NOTE: A minimum of 72 hours curing time at 70°F is required per patch. A minimum of 144 hours is required to installan outside andinside patch. Add20 hours curetime for each 10°F drop in temperature. Never attempt to air cure at temperatures below 60°F.
(s)
Removeplateand boards fromcell. Dampencellophaneand remove fromcell.
(t)
Check for completeseal of patch edges.
(1.) Trim loose edgesif less than 1/8 inch.
(2.) Bond loose edgeswith cement and cure if more than 1/8/ inch.
(u) Repeatsteps(a) thru (t) for inside patch,exceptcutpatch 1/4 inch to 1/2 inch smallerthan outsidepatch.
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PIPERAIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCE MANUAL
A. Storage(continued)
18.RepairPatch (Quick Cure Method)
WARNING: REMOVE FUEL CELL FROM AIRCRAFT BEFORE PERFORMING QUICK CUREMETHOD.
CAUTION: USE EITHER HEAT CURE OR AIR CURE METHOD IF DAMAGE IS WITHIN 5/8 INCH FROM OUTSIDE DIAMETER OF METAL FITTINGS
(a)Cut repair patch from 3604N fabric material to size that extends 1.0 inch beyond injury in all directions
NOTE: It is recommended be used.
that a round patch 3 inches in diameter
WARNING: MEK IS FLAMMABLE. TAKE ALL NECESSARY PRE-CAUTIONS TO PREVENT SERIOUS INJURY TO YOURSELF AND/OR FELLOW WORKERS.
(b)Wash fuel cell approximately 12 inches beyond injury in all directions using a cloth dampened with MEK.
(c) Center fabric patch over injury. Mark cell 0.50 inch beyond patch in all directions.
CAUTION: BUFF FUEL CELL WITH CARE TO PREVENT DAMAGE BEYOND INJURY AND TO PROTECT CELL FABRIC REINFORCEMENT.
(d)Buff fuel cell inside marked area with a Scotch Brie pad or fine emery cloth to remove gloss/shinefrom cell.
(e)Wash buffed area using a clean, lint free cloth dampened with MEK. Repeat with a second clean cloth.
CAUTION: DO NOT MIX CEMENT BATCHES SMALLER THAN AS SUPPLIED AS UNRELIABLECURE CONDITIONS CAN RESULT.
(f) Mix82C32 cement as follows:
(1.) Pour contents of part 2 into container of part 1.
(2.) Thoroughly stir contents with a tongue depressor for about 5 minutes.
NOTE: Pot life of mixed 82C32 cement is about 20 to 30 minutes in and open container. Pot life can be extended up to 1 hour by recapping containerbetween applications.
EFFECTIVITY:
040-999
28-10-00PAGE
Jan10/90
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本文链接地址：夏延飞机维护手册 Cheyenne IIIA PA-42-720 AMM 1(133)
