Fibegrlas Fracture And Patch Repairs - Piper PA-24 Comanche Service Manual

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PIPER COMANCHE SERVICE MANUAL
cellol)b.,. an::l allow to cute completely for 30 minutes to uhour. The pitch will shrink aliahtly
below the structure sunace u it cure••
(If
wax paper is ued. ucertaie wax is Iemoved from
surface.)
C. ROUlh up the bottom led edC- of tM hole with
the
electric burr attachment or rolllh sead
papet. Feather llole into .urrouedinc ,el coat. do not lIDd.rcut.
h. Pour out a .mall amount
of
mia• •4 catalyst and lIis thorOQlh1y, usinc I cuttincmotioR
rath.r than stimnc. Use no fibers.
i. USial the tip of a putty knife or fin,.r
tipl,
fill t . hole to about 1/16 inch above the
sutrOlIIldinc surface with tbe ..1 coat mixture.
i ,
Lay a piece of cellophane ewer the petch to stan the curia, process. Repeat atep f.
ttimminl patch _hen partially cured.
k. After trimlllinc the patCh. iaullediataly place another small Imout
of ..
1 coat
012
one edC'
of tbe patch and cover with cellopha•. Then. usiaC I .qu..... or the
back
of a ruor blade.
sqU"Cee level with area surroWldinl the patch; le.ve the cellopbaae on patch for aae to two
hours or overnight, for complete cure.
1. Aft.r tepair has cured for
24
hows, saad petched a..a. ailll I saadiDI block with fine
wet sandpaper. Finish by primine. IClin saadinl and applyiq color coat.
4-46. Filter,lal Fracture AMI
Pitch
Re,.ira.
a. Remove wax. oil and dirt from aroUlld the de_pel IntI with acetone. _thylethylketone
or equivalent.
b. Usil1C a Itey hal. aa•• elec:tric saber .... or sharp knife cut away raaed edps. Cl,lt
back to sound material.
c. Remove paint three ineb.. back from around dalll8pd area.
d. Workinc inside the structure. bevel the
eel...
to appn:ntimately a 30 deCree ancle and
rOUlh-sand the hole and the area lround it, usilll 80 lrit dry ,-per. Feather back for about two
inches all .round the hole. This rouchetlS the surface for
ItfOlll
boad with patch.
e. Cover a piece of car.fboard or metal with cellopba•• Tape it to the outside of the strue-
ture. covering the hole completely. The cellophane should face toward the i,.ide of the structure.
If the repair is on a slulrp contour or shaped area, a sbeet of Iluminum for_d to a sill1ilar con-
tour lIlay be placed over the area. The aluminum showd also be covered with cellophane.
f. Prepare a patch of fiber&1u rut and cloth to cov.r an area two illChes laraer than the
hole.
&. "'ix a small alllOUl1t of resin
.ad catalyst, enouch to be .. eli for one step at a time, ac ..
cording to kit instNCtiOns.
h. Thoroulhly wet mat and cloth with catalyzed resin. Daub resin on mat first. and then on
cloth. Ylat should be applied apiat structures lurface with cloth on top. Both pieCH may be
wet out on cellophane and applied as a sanet-ich. Enoqb fibercl" cloth and lIIat reicforcements
should be
I1sed
to at least replace the amount of reinforce_Dts removed in order to maintain
the orilinel Sttenlth. If damace occurted as a stress crack, an extra layer or two of cloth may
be used to Strenlthen am.
l , L.ay patch over hole on inside of structure, cover with cello
I'
han. , and squeegee from
center to
edges
to remove all air bubble. and
HaUfe
lIdhesion around
Idee
of hal•. Air bubbl.s
w
tll show white in the patch and they should all be worad out to the
edee.
Remove excess resin
beiore it gels on the
Plrt. Allow
patch to Cure completely.
j.
Remove cardboard or aluminum sheet from outside of hole and roulh-sand the I)_tch and
edge of hole. Feather edge of hole about two inches into- unda• •ed area.
STRUCTURE
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