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Illinois Urban Manual
Instructions For Use of Construction Specification 82
PAINTING METALWORK
List
of Construction Specifications
Table of Contents
1. Applicability
Construction Specification 82 is applicable to the
painting of metalwork including structural metal, water control gates,
piping, pumps and other metal equipment and machinery.
The durability of paint films on metal depends upon the
exposure condition, the types of paints used, the thickness of the coating
and the method of preparing the metal surface prior to the application of
primers and paint. To a large extent the type of paint required is dictated
by the exposure condition and the required surface preparation is dictated
by the type of paint to be applied. Each paint system specifies the type and
quality of paint, the number of coats or minimum paint film thickness
required and the finish (gloss, semi-gloss, flat, etc.).
The paint systems are not equivalent optional methods.
Each paint system is designed to provide protection for a particular
exposure condition or to produce a particular finished appearance or both.
The criteria for selection of the appropriate paint system and surface
preparations for that finish are summarized in Table A-82 of these
instructions.
Where a minor amount of painting is to be performed, and
it is not required for protection, use a simple note on the drawings rather
than Construction Specification 82.
2. Material Specifications
Material Specification 583, Coal Tar-Epoxy Paint, is
complementary to Construction Specification 82 when Paint System F is
specified. References to the Steel Structures Paint Council (SSPC) for
surface preparation are summarized. Refer to SSPC for full text as
appropriate. There are no other material specifications complementary to
this specification. Any material requirements are to be specified in Section
10.
3. Items to be Included in
Contract Specifications and Drawings
a. Indicate by notes on the drawings, the surfaces and
items to be painted.
b. Designate the paint system (by letter) to be used for
painting each indicated item. If all metalwork is to be painted by the same
paint system, one standard note to that effect will be sufficient.
c. Waiver of the requirement that the Contractor furnish a
plan and materials list, if the plan is not necessary.
d. Provide color requirements, finish (gloss, semi-gloss,
etc.) and any special requirements as appropriate.
e. Instructions for painting, surface preparation or other
special conditions or methods not covered by the standard specification.
f. Surface preparation for needed maintenance painting may
be limited to those spots or areas having loss of protection by corrosion
and/or wearing surfaces. A clean sound paint surface provides a good base
for added layers.
g. Provide tinting requirements as appropriate. Various
coatings have a unique tolerance for pigmentation. Under or
over-pigmentation can produce poor cover quality (hide) and less than
desirable performance.
h. Note in Section 10 if the Contractor is to provide
paint specification information to the Engineer which is to be shared with
the owners to use for their responsibility for operation and maintenance.
4. Discussion of Methods
Select the method or methods for surface preparation that
are appropriate for the durability and length of service required. Refer to
Table A-82 for surface preparation recommendations. The quality of surface
preparation diminishes as the Method number increases and the expected
surface life is reduced accordingly. The small cost increase in selecting a
higher quality preparation can significantly reduce O&M costs and
untimely coating failure.
TABLE A-82
PAINT SYSTEMS FOR METALWORK
Paint
System
|
Type of Paint
Material
|
Description and Conditions for Use
|
Example Applications
|
Surface Preparation
|
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A
|
Alkyd Primer
(Type 1)
Alkyd Enamel (Type 2)
Gloss or
Semi-gloss (Type 3)
|
A good interior and exterior system. It is not intended for humid or
damp environments. System A should not be applied to surfaces that
constantly sweat or are immersed in water. It will chalk or oxidize
when subjected to sunlight.
|
Interior and exterior surfaces of buildings, piping, pumps, and
machinery above operating floors, doors, frames, tanks, etc.
|
Method 2 or 3,
Commercial Blast or Brush-off Blast
|
|
B
|
Single package moisture cured urethane primer
(Type 9)
Alkyd Enamel
(Type 2)
Gloss or
Semi-gloss (Type 3)
|
Similar to the qualities of System A. Urethane primer allows system to
be applied over poorly prepared surfaces particularly in areas where
proper preparation is difficult or impractical. It is a good system
for repainting over old existing paint for rehabilitation.
|
Exterior or interior surfaces of buildings, piping, pumps, and
machinery above operating level. Good rehabilitation system when
preparation is minimal.
|
Method 2 or 3, Commercial Blast or Brush-off Blast
|
|
C
|
Epoxy
Polyamide
(Type 4)
Epoxy
Polyamide
(Type 5)
|
An excellent system for constant or intermittent immersion in salts or
fresh water. Excellent for surfaces exposed to constant humidity and
sweating. Excellent chemical resistance and available in almost all
colors. Will chalk or oxidize when exposed to sunlight.
|
Trash racks and guards or flap gates, stop logs and guides, pumps,
piping, machinery, storage tanks, etc.
|
Method 1, near white Blast.
|
|
D
|
Epoxy Polyamide Primer
(Type 4)
Epoxy Polyamide
(Type 5)
Acrylic Polyurethane Gloss (Type 6) or Semi-gloss (Type 7)
|
Same as System C except is topcoated with acrylic polyurethane. Not
recommended for immersed metals. Excellent interior or exterior in
humid or arid environment. High abrasion resistance. Excellent color
and gloss retention (15 times greater than Systems A, B, or C).
Excellent on steel that sweats. Available in either gloss or
semi-gloss. Should be considered for long-term exposure to sunlight or
when esthetics are a factor.
|
Exterior surfaces of building such as drains, overflows, gutters and
piping exposed to either humid or arid conditions. Any metal items
that gather condensation and/or have high exposure to sunlight.
Interior surfaces such as walls, ceilings, structural steel,
equipment, piping, etc.
|
Method 2 or 3, Commercial Blast or Brush-off Blast
|
TABLE A-82 PAINT SYSTEMS FOR METALWORK (Continued)
|
Paint
System
|
Type of Paint
Material
|
Description and Conditions for Use
|
Example Applications
|
Surface Preparation
|
|
E
|
Single package moisture cured Urethane Primer
(Type 9)
Acrylic
Polyurethane Gloss (Type 6) or Semi-gloss (Type 7)
|
Good system for dry humid environments. Excellent color and gloss
retention. Cannot be used for coating immersed metals and is not as
good as System D in constant moisture. Excellent long-term esthetics.
|
Structural steel, siding, doors, frames, piping, machinery, storage
tanks, etc.
|
Method 2 or 3, Commercial or Brush-off Blast
|
|
F
|
Coal Tar
Epoxy
(Type 10)
|
Excellent in constant or intermittent immersion in salt or fresh
water. Excellent also for buried steel surfaces. Available in black
only – will change to brown when exposed to sunlight, but sunlight
does not adversely effect performance. Excellent chemical resistance
and dependability exhibited in extensive use throughout the water and
wastewater treatment industry.
NOTE: Galvanized surfaces require a pre-treatment vinyl acid wash
primer prior to applying paint, as noted in Type 8 Paints.
Sandblasting or aged galvanized surfaces do not require a vinyl
wash treatment.
|
Trash guards, water control gates, pipes, steel piling, stop logs and
guides, water tanks, flumes, etc.
|
Method 1, Near White Blast
|
|
G
|
Epoxy Polyamide Primer
(Type 4)
Single package Moisture Cured Urethane
(Type 9)
|
Excellent system for repair of damaged galvanized metal in humid or
arid environments. Will provide protection for surfaces exposed to
constant humidity and sweating.
|
Trash guards, CMP, stop logs and guides, and other galvanized
metalwork.
|
Method 4 or 5, Hand Tool or Solvent Clean
|
|
H
|
Vinyl Acid
Wash
Treatment
(Type 8)
|
For use as a pre-treatment wash for galvanized and non-ferrous metals
that require painting.
|
Trash guards, CMP, stop logs and guides, gutters, downspouts, and
other galvanized or non-ferrous metals.
|
Steam Clean with TSP, or Solvent clean, regularly changing rags.
|
a. All surface preparation referred to herein shall be
performed in accordance with SSPC (Steel Structures Painting Council).
b. All painting and coating shall be performed per SSPC
Good Painting Practices and paint manufacturer’s recommendations.
c. Coated steel subjected to potable water service shall
be coated in accordance with American Water Works Association (AWWA)
provisions and directions. Said coatings shall meet United States National
Sanitation Foundation (US-NSF) requirements.
d. When special protective coatings or other specific
painting recommendations are necessary, refer to the Paint Manual, United
States Department of Interior (USDI), Bureau of Reclamation or paint
manufacturer’s data.
e. Surface preparation indicated is the method that will
provide coating quality appropriate for exposure conditions. Methods that
produce a greater or a lesser quality can be chosen to produce the quality
of work that is necessary. Hand Tool Cleaning (Method 4) and Solvent
Cleaning (Method 5) are applicable for field applications, small areas
requiring coating, or in making repairs to factory coatings.
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