Piper Cherokee LANCE, Service Manual

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PIPER CHEROKEE SIX / LANCE SERVICE MANUAL
07/15/06 IV - STRUCTURES
1F17
h. Thoroughly wet mat and cloth with catalyzed resin. Daub resin on mat first, and then on cloth. Mat
should be applied against structures surface with cloth on top. Both pieces may be wet out on
cellophane and applied as a sandwich. Enough fiberglass cloth and mat reinforcements should be
used to at least replace the amount of reinforcements removed in order to maintain the original
strength. If damage occurred as a stress crack, an extra layer or two of cloth may be used to
strengthen area.
i. Lay patch over hole on inside of structure, cover with cellophane, and squeegee from center to
edges to remove all air bubbles and assure adhesion around edge of hole. Air bubbles will show
white in the patch and they should all be worked out to the edge. Remove excess resin before it gels
on the part. Allow patch to cure completely.
j. Remove cardboard or aluminum sheet from outside of hole and rough-sand the patch and edge of
hole. Feather edge of hole about two inches into undamaged area.
k. Mask area around hole with tape and paper to protect surface. Cut a piece of fiberglass mat about
one inch larger than the hole and one or more pieces of fiberglass cloth two inches larger than the
hole. Brush catalyzed resin over hole, lay mat over hole and wet out with catalyzed resin. Use a
daubing action with brush. Then apply additional layer or layers of fiberglass cloth to build up patch
to the surface of structure. Wet out each layer thoroughly with resin.
1. With a squeegee or broad knife, work out all air bubbles in the patch. Work from center to edge,
pressing patch firmly against the structure. Allow patch to cure for 15 to 20 minutes.
m. As soon as the patch begins to set up, but while still rubbery, take a sharp knife and cut away extra
cloth and mat. Cut on outside edge of feathering. Strip cut edges of structure. Do this before cure is
complete, to save extra sanding. Allow patch to cure overnight.
n. Using dry 80 grit sandpaper on a power sander or sanding block, smooth patch and blend with
surrounding surface. Should air pockets appear while sanding, puncture and fill with catalyzed
resin. A hypodermic needle may be used to fill cavities. Let cure and resand.
o. Mix catalyzed resin and work into patch with fingers. Smooth carefully and work into any crevices.
p. Cover with cellophane and squeegee smooth. Allow to cure completely before removing
cellophane. Let cure and resand.
q. Brush or spray a coat of catalyzed resin to seal patch. Sand patch, finish by priming, again sanding
and applying color coat.
NOTE: Brush and hands may be cleaned in solvents such as acetone or methylethylketone. If
solvents are not available, a strong solution of detergent and water may be used.
4-23. SAFETY WALK REPAIR/REPLACEMENT.
4-23a. PRESSURE SENSITIVE SAFETY WALK.
a. Surface Preparation
The areas to which the pressure sensitive safety walk is to be installed must be free from all
contaminates and no moisture present. If liquid safety walk is installed the area must be prepared as
follows:
(1) Area must be masked off to protect painted surfaces.
(2) Apply suitable stripper MEK Federal Spec. TT-M-261, U.S. Rubber No. 3339 to wingwalk
compound. As compound softens remove by using putty knife or other suitable tool.