portionanddamage portion of grease, dirt, or talc. Useneutral soap and water solution, rinseclean,and dry with clean cloth. (2.) Washrepair area carefullywithcleanclothmoistenedin Toluol or Methylethylketone (MEK),FederalSpecificationTT-M-261. (3.) When routingarounddeicerinjury,removeorcoverall cement containersto prevent particlesfromgrindingstone from contaminating
cement. (4.) After buffingorroutingan area, removeall dust fromdeicerand table surfaces. (5.) Protect all completed repairsfrom dust and dirt withcleanpieceof holland cloth. Hold clothin place with masking tape. Removemaskingtapebeforecuring. (6.) Releaseallairtrappedbetweengum,fabric,anddeicer surfaces byinsertinghypodermic
needlethroughplyto air pocket. (7.) Removeall excess cementanddustparticlesby washing withsolvent. (8.) Useclean brushes whenmakingrepairs.CleancementbrusheswithBenzineor non-
leadedgasoline. (9.) Useapprovedsafetycanfor Toluol or MEK. Remove springandscreenout of solvent cansbeforefilling. (10.)Ensurecementsare applied in a thin smoothcoating.If partiallysetup or lumpy,addition
of proper solventrestoresusablecharacteristics. (11.)Do not attemptrepairsin temperature under40°F. (12.)Whenhumidityishigh,wipe moisture off with a solvent dampenedcleanclothbefore
proceedingwithrepair. (13.)Whenrepairingdeicers,keepmaterial,tools,equipment,and hands cleanat all times.
EFFECTIVITY:
040-999 Jan 10/9030-10-00
Jan 10/90
PIPERAIRCRAFT
PA-42-720(AdvancedTrainer)
MAINTENANCEMANUAL
A. Airfoil -Descriptionand Operation (continued)
(f) Curing
The vulcanizer listed in Chart 5 is adjusted at the factory to heat to 285 ° + 5°F, using line
voltagespecifiedon the name plate. All curing times in this manual are for 285°F. If line
voltageis low, the vulcanizer will not heat to 285°F and curing timesare longer than specified.
Sincecuringtime varies with type and position of repair, timesare given for each specifiedtype
of repair.
Curerepairas follows:
NOTE: Over-curingdestroysthe flexibility of deicer. Under-curing prevents proper bonding. Always watch cure time and temperaturecarefully.
(1.) Preheat vulcanizer.
(2.) Place sponge pad over bottom of unheatedplate.
(3.) Place piece of clean, unwrinkled (or silicone treated)paper over sponge pad and deicer
over hollandwith area to be cured centrally located over bottom platen. (Repairsideup.) (4.) Place another piece of smooth, clean holland over area.
NOTE: If holland or silicone treated paper is not available, spread thin coat of soapy water over surfaces of metal curingsheet and sponge pad. Allow to dry thoroughly.
(5.) Place metal curing sheet over holland and clamp heating element in place. Ensure metal
curingplate is at least 1 inch larger overall than heating plate. Hand tighten heater firmly. (6.) Cure full allottedtime for each repair. (7.) Test each repair thoroughly after it has cured. Flex and stretch area by hand several
times and in a tube; inflate to 25 psig.
(g) SurfaceScuffs
(1.) Wash surface, apply one coat of conductive cement,and allow to dry thoroughly. Add anothercoat and allow to dry. Dip finger in conductive cement solvent (Isopropyl Acetate) and rub down with light circular movement.
(2.) Wipe surface lightly with Isopropyl Acetatemoistenedcloth.
(3.) Allow to dry thoroughly. Dust lightly with soapstone.
(h) Deep Scuff ThroughNeopreneSurface
(1.) Mark area and carefully cut 0.010 inch Neoprene surface ply with knife. Prevent surface ply from peeling beyond marked area when using buffer. Ensure area includes full width of tube and approximately 1/2-inchbeyond scuff.
(2.) Using buffer, route down until all pits are removed. Buff 1/8-inch aroundouter edge of routedarea. Mask off outside of buffed area and cement. (3.) Using mill or putty knife, apply Neoprene putty. Fill cavity flush with surface and ensure cavity is completely filled. Remove masking tape and cure for 20 minutes. (4.) Restore conductive surface.
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