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Fundamentals of Corrosion
7.9 Selecting a Paint System
The first step in selecting a paint system for corrosion protection is to determine the environment around the structure or item to be painted. Is the
environment predominantly a weathering environment subject to heat,
cold, daily or seasonal temperature changes, precipitation, wind (flexing),
exposure to sunlight, or detrimental solar rays? If the structure or item is
located outdoors, are there chemical plants nearby, or pulp and paper mills,
or other industrial facilities that are apt to discharge airborne pollutants? Is
color, gloss, and overall pleasing effect more important than corrosion protection, or are the normal grays, whites, and pastels of the more corrosionresistant paints satisfactory? If located in a chemical facility, what specific
chemicals are used nearby? Is there any chance of a chemical spill on the
painted surface?
Because surface preparation is an important factor in the selection of a
paint system, the suitability or availability of the surface for specific preparation techniques must be known. In some instances, certain types of surface preparation may not be permitted or practical. For example, many
companies do not permit open blast cleaning where there is a prevalence
of electric motors or hydraulic equipment. Refineries, in general, do not
permit open blast cleaning or any other method of surface preparation that
might result in the possibility of a spark, static electricity buildup, or an
explosion hazard.
If a new facility is being constructed, it is possible that during erection many areas may become enclosed or covered or so positioned that
access is difficult or impossible. These structures must be painted prior to
installation.
When all this information has been collected, appropriate paint systems may be selected. In most instances, it will not be practical or possible to select one single coating system for the entire plant. There will be
areas requiring systems to provide protection from aggressive chemicals,
whereas other areas may require coating systems simply for aesthetics.
If an area is a combination of mild and aggressive conditions, a coating
system should be selected that will be resistant to the most aggressive
condition.
Several typical industrial areas have been illustrated that coating systems
may be exposed to, with recommendations for paint systems to be used in
these areas. The paint systems are shown in Table 7.13 through Table 7.18
with the appropriate surface preparation. These tables have been arranged
based on surface preparation. Each coating system shown in a particular
table requires the same surface preparation.
Fundamentals of Corrosion
7.9 Selecting a Paint System
The first step in selecting a paint system for corrosion protection is to determine the environment around the structure or item to be painted. Is the
environment predominantly a weathering environment subject to heat,
cold, daily or seasonal temperature changes, precipitation, wind (flexing),
exposure to sunlight, or detrimental solar rays? If the structure or item is
located outdoors, are there chemical plants nearby, or pulp and paper mills,
or other industrial facilities that are apt to discharge airborne pollutants? Is
color, gloss, and overall pleasing effect more important than corrosion protection, or are the normal grays, whites, and pastels of the more corrosionresistant paints satisfactory? If located in a chemical facility, what specific
chemicals are used nearby? Is there any chance of a chemical spill on the
painted surface?
Because surface preparation is an important factor in the selection of a
paint system, the suitability or availability of the surface for specific preparation techniques must be known. In some instances, certain types of surface preparation may not be permitted or practical. For example, many
companies do not permit open blast cleaning where there is a prevalence
of electric motors or hydraulic equipment. Refineries, in general, do not
permit open blast cleaning or any other method of surface preparation that
might result in the possibility of a spark, static electricity buildup, or an
explosion hazard.
If a new facility is being constructed, it is possible that during erection many areas may become enclosed or covered or so positioned that
access is difficult or impossible. These structures must be painted prior to
installation.
When all this information has been collected, appropriate paint systems may be selected. In most instances, it will not be practical or possible to select one single coating system for the entire plant. There will be
areas requiring systems to provide protection from aggressive chemicals,
whereas other areas may require coating systems simply for aesthetics.
If an area is a combination of mild and aggressive conditions, a coating
system should be selected that will be resistant to the most aggressive
condition.
Several typical industrial areas have been illustrated that coating systems
may be exposed to, with recommendations for paint systems to be used in
these areas. The paint systems are shown in Table 7.13 through Table 7.18
with the appropriate surface preparation. These tables have been arranged
based on surface preparation. Each coating system shown in a particular
table requires the same surface preparation.