Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 371 / 881

B. B u ff the area around the damage with buffing stick, Part No. 74-451-75, so that the surface is
thoroughly roughened.
C. Apply the patch to the deicer with the stretch in the widthwise direction of the inflatable tubes, sticking
edge of patch in place, working remainder down with slight pulling action so the injury is closed. Do
not trap air between patch and deicer surface.
3. LOOSE SURFACE PLY IN DEAD AREA (NON-INFLATABLE AREA). Peel and trim the loose surface
ply to the point where the adhesion of surface ply to the deicer is good.
A.
Scrub (roughen) area in which surface ply is removed with steel wool. Scrubbing motion must be
parallel to cut edge of surface ply to prevent loosening it. Scrub with steel wool and Toluol directly
over all edges, but parallel to edges or surface ply to taper them down to the tan rubber ply.
B. Cut a piece of surface ply material, Part No. 74451-23, to cover the damaged area and extend at least
one inch beyond in all directions.
C. Mask off the damaged boot area 1/2 inch larger in length and width than the size of surface ply patch.
Apply one coat of cement, Part No. 74-451 - 11, to damaged area and one coat to patch. Allow cement
to set until tacky.
Roll the surface ply to the deicer with 2 inch rubber roller, Part No. 74-451-74. Roll edges with stitcher-
r o l l e r, Part No. 74-451-73. Apply just enough tension on the surface ply when rolling to prevent
wrinkling and be careful to prevent trapping air. If air blisters appear after surface ply is applied,
remove them with a hypodermic needle.
D. Clean excess cement from deicer with solvent.
4. LOOSE SURFACE PLY IN TUBE AREA. Loose surface ply in tube area is usually an indication of the
deicer starting to flex fail. This type of failure is more easily detected in the form of a blister under the
surface ply when deicer is pressurized. If this type of damage (or void) is detected while still a small blister
(about 1/4 or 3/8 inch diameter) and patched immediately, the service life of the deicer will be appreciably
extended. Apply repair patch as outlined in Paragraph 1.
5. DAMAGE TO FABRIC BACK PLY OF DEICER DURING REMOVAL. If cement has pulled loose from
the wing skin and adhered to the back surface of the deicer, remove it with steel wool and MEK. In those
spots where the coating has pulled off the fabric, leaving bare fabric exposed, apply at least two additional
coats of cement, Part No. 74-451-24. Allow each coat to dry thoroughly.
VULCANIZED REPAIRS.
Due to the variety of boot damage possible, it is recommended that the B. F. Goodrich Company be contacted
so they can determine the extent of damage and whether it is repairable by the vulcanized method or not. The
overall condition of the deicer boot must be given careful consideration before deciding on any repairs. Damages
can vary from minor punctures which may be easily repaired, to extensive ripping of the tube or stretch areas
which may make repairs exceedingly difficult or actually impossible. The determination of just where this
division between repairable and unrepairable damage exists will depend upon the careful judgment of the
inspector. For this reason, we recommend contacting the B. F. Goodrich Company at Akron, Ohio.
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
3 0 - 1 3 - 0 8
Page 30-11
Revised: May 15, 1989
2D15
PIPER AIRCRAFT