Common Paint Troubles; Storage; Painting Facility - Piper Dakota Maintenance Manual

7. Old acrylic finishes may be refinished with new acrylic provided old coating is thoroughly softened
using acrylic nitrocellulose thinner before paint touchup.
8. Damage to epoxy finishes can be repaired using more epoxy. Neither lacquer finish will stick to epoxy
surfaces. In some instances, air drying enamels may be used for touchup of epoxy coatings if edges of
damaged areas are first roughened with abrasive paper.

COMMON PAINT TROUBLES

l. Poor Adhesion - Paint properly applied to correctly pretreated surfaces should adhere satisfactorily.
When thoroughly dry, paint should not be easily removed. Poor adhesion results from one of the
following:
a. Inadequate cleaning and pretreatment.
b. Inadequate stirring of paint or primer.
c. Coating at incorrect time intervals.
d. Application under adverse conditions.
e. Bad application.
2. Spray Dust - Spray dust is caused by atomized particles becoming dry before reaching surface being
painted and thus failing to flow into a continuous film. Usual causes are incorrect air pressure or
distance gun is held from work.
3. Sags and Runs - Sags and runs result from applying too much paint. This causes film of wet paint to
move by gravity and present a sagging appearance. Incorrect viscosity, air pressure, and gun handling
are frequent causes. However, inadequate surface preparation may also be responsible.
4. Spray Mottle - Sometimes known as orange peel or pebble, is usually caused by incorrect paint
viscosity, air pressure, spray gun setting, or the distance the gun is held from the work.
5. Blushing is one of the most common troubles experienced. It appears as a "clouding or "blooming" of
the paint film. It is more common with cellulose than synthetic materials. It may be caused by
moisture in the air supply line, adverse humidity, drafts, or sudden changes in temperature.

STORAGE

Paint, enamel, and other finishing material must be stored in a dry place away from direct sunlight and
heat. Mark each container with a code and color number identifying material.
Storage facilities must conform to Occupational Safety and Health Act (OSHA) requirements regarding air
circulation, lighting, and fire protection. It must also be locked to prevent children and unauthorized personnel
from getting inside.
Invert pigmented materials at every inventory so pigments will not have as much of an opportunity to pack
to bottom of can. Dispose of empty containers properly.
Useful life of some finishes is limited, use older materials first.
Storage area temperatures must be approximately 50°-90°F. If finishes are stored in temperature extremes,
allow them to come to room temperature before using.

PAINTING FACILITY

Do not breath paint fumes as they deplete the oxygen supply
required by the body.
PIPER AIRCRAFT
PA-28-236
MAINTENANCE MANUAL
—WARNING—
1F2
20 - 25 - 00
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Reissued: August 1, 1986