Piper Cherokee LANCE, Service Manual

Page: 117 / 854

PIPER CHEROKEE SIX / LANCE SERVICE MANUAL
03/27/08 IV - STRUCTURES
1F9
Figure 4-4. Surface Scratches, Abrasions or Ground-in-Dirt
4-19b. GENERAL THERMOPLASTIC REPAIRS. The following procedure will assist in making field
repairs to items made of thermoplastic which are used throughout the airplane except for wheel and strut
fairing. A list of material needed to perform these repairs is given along with suggested suppliers of the
material. Common safety precautions should be observed when handling some of the materials and tools
used while making these repairs.
a. Surface Preparation:
1. Surface dirt and paint if applied must be removed from the item being repaired. Household
cleaners have proven most effective in removing surface dirt.
2. Preliminary cleaning of the damaged area with perchlorethylene or VM&P Naphtha will
generally ensure a good bond between epoxy compounds and thermoplastic.
b. Surface Scratches, Abrasion or Ground-in-Dirt: (Refer to Figure 4-4.)
1. Shallow scratches and abraded surfaces are usually repaired by following directions on
containers of conventional automotive buffing and rubbing compounds.
2. If large dirt particles are embedded in thermoplastic parts, they can be removed with a hot air
gun capable of supplying heat in the temperature range of 300° to 400° F. Use care not to
overheat the material. Hold the nozzle of the gun about 1/4 of an inch away from the surface
and apply heat with a circular motion until the area is sufficiently soft to remove the dirt
particles.
3. The thermoplastic will return to its original shape upon cooling.
c. Deep Scratches, Shallow Nicks and Small Holes: (Less than I inch in diameter.) (Refer to Figure
4-4a.)
1. Solvent cements will fit virtually any of these applications. If the area to be repaired is very
small, it may be quicker to make a satisfactory cement by dissolving thermoplastic material of
the same type being repaired in solvent until the desired paste-like consistency is achieved.