Adhesion Test; Deicers Maintenance; Agemaster No. 1 And Icex Application - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
14-83. ADHESION TEST. Using excess boot material trimmed from the ends of any wing and empennage
deicers, prepare one test specimen for each deicer installed. This specimen should be a 1 x 8 inch full
thickness strip of boot material cemented to the wing skin adjacent to installed boot following the identical
procedure used for installation. Leave one inch of the strip uncemented to attach a clamp. Four hours or more
after the installation, attach a spring scale to the un-cemented end of each strip and measure the force required
to remove strip at the rate of one inch per minute. The pull should be applied 180
°
to the surface. (Strip
doubled back on itself.)
A minimum of five pounds tension (pull) shall be required to remove the test strip. If less than five pounds
is required, than acceptability of the boot adhesion shall be based on the following tests:
a. Carefully lift one corner of boot in question sufficiently to attach a clamp.
b. Attach a spring scale to this clamp and pull with force 180
°
to the surface and in such a direction that
the boot tends to be removed on the diagonal.
c. If a force of five pounds per inch of width can be exerted under these conditions, the installation shall
be considered satisfactory. Remember, the width increases as the comer peels back.
d. Re-cement comer following previous procedure.
e. Failure to meet this requirement shall result in reinstallation of the boot.
NOTE
Possible reasons for failure are: dirty surfaces, cement not reacti-
vated properly, cement not mixed thoroughly. Corrosion of the
metal skin may occur if good adhesion is not attained, especially
around rivet heads and metal skin splices.
If these adhesion requirements are met, the airplane may be flown immediately. Do not inflate deicers
within 12 hours of installation or until adhesion strength of 8 to 10 pounds is obtained.
14-84. MAINTENANCE. Clean deicers when the airplane is washed with a mild soap and water solution. In
cold weather, wash the boots with the airplane inside a warm hangar if possible. If the cleaning is to be done
outdoors, heat the soap and water solution before taking it out to the airplane. If difficulty is encountered with
the water freezing on the boots, direct a blast of warm air along the region being cleaned, using a portable type
ground heater.
As alternates, use Benzol or non-leaded gasoline. Moisten the cleaning cloth in solvent, scrub lightly, and
then, with a clean, dry cloth, wipe dry so that the cleaner does not have time to soak into the rubber. Petroleum
products such as these are injurious to rubber and, therefore, should be used sparingly.
14-85. AGEMASTER NO. 1 AND ICEX APPLICATION. Agemaster No. I and Icex are chemical treat-
ments that will when properly applied increase the life and efficiency of the deicer boots. Although not
required it is recommended that both the Agemaster and Icex treatments be applied when treating boots.
Agemaster No. 1 is a chemical treatment that penetrates and bonds to the rubber surfaces. protecting them
effectively from ozone attack and premature deterioration. To insure proper protection of the deicer boots.
Agemaster No. 1 should be applied at 150 flight hour intervals and prior to Application of Icex.
Icex is a specially compounded silicone base material which effectively reduces the adhesion of ice to
rubber. This compound was developed for use on deicer boots, rubber abrasion boots and other rubber surfaces.
When properly applied and renewed at recommended intervals (at 150 flight hour intervals), Icex will increase
the life and efficiency of the deicer boots and provide a smooth polished film that evens out the microscopic
irregularities on the rubber surfaces to assist the boots in removing ice quickly and cleanly. Although not
required it is recommended that Icex treatments be applied when treating boots.
Revised: 3/31/94
ACCESSORIES AND UTILITIES
4G9