MIL-HDBK-1110
rising, to prevent moisture from condensing on the surface of the
wet paint film. The specification should state how frequently
temperature and dew point measurements should be taken.
Spray painting should also be restricted during times
of moderate to heavy winds. Painting at such times may not only
produce unsatisfactory films of coating but also result in
overspray onto automobiles or other structures in the area.
8.3.3.2
Surface Preparation. It is always best to describe the
desired prepared surface condition, using standards such as SSPC
SP 6, if available, rather than telling the contractor how to
prepare the surface. It is inappropriate to specify both the
desired condition and how to achieve it. These requirements may
cause legal problems if the surface cannot be obtained using the
directions specified. For example, it is much more effective to
require a "SSPC SP 10, Near-White Blast Cleaning" without
specifying how the blaster achieves it. However, if the
specification calls for abrasive blasting of steel at 90 to 100
psi using a venturi nozzle held 8 inches from the surface, then
there can be no requirement for a particular degree of
cleanliness other than that which is achieved when the specific
directions are followed.
Care must also be taken to use only standard terms such
as "brush-off blast cleaning" which is defined in SSPC SP 7
rather than "brush blast," "sweep blast," "shower blast," or some
other undefined term. Also avoid other vague terms such as
"heavy abrasive blasting" that are subject to interpretation.
8.3.3.3
Coating Application. Normally, painters are permitted
to apply their materials by brush, roller, or spray, unless the
material can only be applied satisfactorily by one or two of
these methods. Thus, zinc-rich coatings should be applied by
spray using an agitated pot and following the instructions of the
coating supplier. SSPC PA 1 may be referenced as an industrial
standard for shop and field painting. Local transfer efficiency
requirements may prevent the use of some types of spray
application (e.g., airless or conventional air spray).
Currently, requirements for transfer-efficient methods of
application are limited to shop work. Any thinning of paints
should be limited to thinner and the amount recommended by the
supplier. It should also be within the limits set by local air
pollution authorities.
8.3.3.4
Inspection. In the inspection section, inspection
requirements should be listed. By referring to standard test
procedures, details of both the procedures and their requirements
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