ITEM 709 – PAINTS
709.1
Description
This
Item covers all paint materials including Vehicles, Pigment, Pastes, Driers,
Thinners and Mixed Paints for steel and wooden structures
709.2
Material Requirements
709.2.1
General
Paint,
except, aluminum paint, shall consist of pigments of the required fineness and
composition ground to the desired consistency in linseed oil in a suitable
grinding machine, to which shall be added additional oil, thinner and drier as
required.
Aluminum
paint shall consist of aluminum bronze powder or paste of the required fineness
and composition to which shall be added the specified amount of vehicle.
The
paint shall be furnished for use in ready mixed, paste or powder form. All
paint shall meet the following general requirements:
a.
The paint shall show no excessive settling and shall easily be redispersed with
a paddle to a smooth, homogenous state. The paint shall show no curdling,
livering, caking or color separation and shall be free from lumps and skins.
b.
The paint as received shall brush easily, possess good levelling properties and
shall show no running or sagging when applied to a smooth vertical surfaces.
c.
The paint shall dry to a smooth uniform finish free from roughness grit, uneveness
and other imperfections.
d.
The paint shall not skin within 48 hours in three quarters filled closed container.
e.
The paint shall show no thickening, curdling, gelling or hard caking after six
(6) months storage in full, tightly covered container at a temperature of 210C.
709.2.2
The
paint shall conform to the requirements of the indicated specifications as
follows:
Red Lead AASHTO
M 72Type I, II, III and IV
Ready-Mixed
Paint
Aluminum
Paint AASHTO
M 69 Type I and II
White
& Tinted Ready-Mixed Paint AASHTO
M 70
Foliage
Green Bridge Paint AASHTO
M 67
Black Paint for Bridges AASHTO
M 68
and
Timber Structures
Basic Lead Silicon Chromate, AASHTO M 229
Ready-Mixed
Primer
709.2.3
The
constituent parts of the paint shall meet the following specifications:
Red
Lead (97% Pb3O4) ASTM
D 83
Iron
Oxide (85% Fe2O3) ASTM
D 84
Aluminum
Powder and Paste ASTM D
962
Magnesium
Silicate ASTM
D 605
Mica
Pigment ASTM
D 607
Titanium
Dioxide ASTM
D 476
Chrome
Yellow ASTM
D 211
Calcium
Carbonate ASTM
D 1199
Basic
Lead-Silicon Chromate ASTM
D 1638
Basic
Carbonate White Lead ASTM
D 81
Zinc
Oxide ASTM
D 79
Chrome
Oxide Green ASTM
D 263
Carbon
Black ASTM
D 561
Lampblack
ASTM
D 209
Prussian
Blue ASTM
D 261
Boiled
Linseed Oil ASTM
D 260
Raw
Linseed Oil ASTM
D 234
Pale
Heat Bodied Linseed Oil Fed
Spec. TT-0-367
Alkyd
Resin Fed.
Spec. TT-R-266
Mineral
Spirit ASTM
D 235
Driers
ASTM
D 600
Turpentine
ASTM D 13
709.2.4
Drier
These
specifications cover both straight oil drier (material free from resins and “gums”),
and Japan drier (material containing varnish “gums”). The drier shall be composed
of lead manganese, or cobalt, or a mixture of any of these elements, combined
with a suitable fatty oil, with or without resins of “gums” and mineral spirits
of turpentine, or a mixture of these solvents. The drier shall conform to the following
requirements:
a. Appearance
- Free from sediment and suspended matter.
b. Flash
Point – (Tag close cup) not less than 300C
c. Elasticity
– The drier when flowed on metal and baked for 2 hours at 1000C shall
have an elastic film.
d. Drying
– It shall mix with pure raw linseed oil in the proportion of 1volume of drier
to 19 volumes of oil without curdling, and the resulting mixture when flowed on
glass shall dry in not more than 18 hours.
d. Color
– When mixed with pure, raw linseed oil in the proportion of 1volume of drier
to 8 volumes of oil, the resulting mixture shall be darker than a solution of 6
g of potassium dichromate in 13 cc of pure sulfuric acid (sp. gr. 1.84).
709.3
Proportion for Mixing
It
is the intent of these Specifications to provide a paint of proper brushing
consistency, which will not run, streak or sag and which will have satisfactory
drying qualities.
709.3.1
Aluminum Paint, Field Coats on Structural Steel
The
paint shall be mixed in the proportion of 0.242 kg of aluminum powder of paste per
liter of vehicle of long oil spar varnish producing a paint containing 21mass
percent pigment and 79 percent vehicle. The weighed amount of powder or paste
shall be placed in a suitable mixing container and the measured volume
of vehicle then poured over it. The paste or powder shall be incorporated
in the paint by vigorous stirring with a paddle. The powder or paste will
readily disperse in the vehicle. Before removing any paint from the container,
the paint shall be thoroughly stirred to insure a uniform mixture and the paint
shall be suitably stirred during the use. The amount of paint enough for one
day’s use only shall be mixed at one time.
When
two field coats of aluminum paint are specified, the first coat shall be tinted
with lampblack paste or Prussian blue paste in the quantity of 0.024 kg/L or
more of paints. The exact quantity used shall be sufficient to give a contrast
in color which can be readily distinguished. When three field coats of aluminum
paint are specified the second coat shall be tinted.
709.3.2
Aluminum Paint, Field Coats on Creosoted Timber
This
paint shall be mixed as specified for Aluminum Paint for Structural Steel except
that the proportions shall be 0.272 kg of aluminum powder or paste per liter
of vehicle.
Other
paint composition may be used when and as stipulated in the Special Provisions.
709.4
Containers and Markings
All
paints shall be shipped in strong, substantial containers plainly marked with
mass, color and volume in liters of the paint content, a true statement of the percentage
composition of the pigment, the proportions of the pigment to vehicle, the name
and address of the manufacturers and the stencil of the authorized inspecting
agency. Any package or container not so marked will not be accepted for use
under this Specification.
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