cement, and nonsilaceous materials; solvent formulations used oil
bricks and noncalcareous masonry.
8.4B ituminous Paints
There are two paints in this category: asphaltand coal tar.
8.4.1 Asphalt Paint
Asphalt paint consists of solids from crude oil refining suspended in
aliphatic solvents.
1. Resistance: Good moisture resistance; good resistance to weak
acids, alkalies, and salts; better weathering properties than coal tar.
2. Temperature resistance: Softensa t1 008 F/388 C.
3. Limitations:Heavy,d ark color hides corrosion under coating.
4. Applications: Used in above-groundw eathering environments
and chemical fume atmospheres.
8.4.2 Coal Tar
Coal tar is adistilled coking by-product in an aromatic solvent.
1. Resistance: Excellent resistance to moisture; good resistance to
weak acids and alkalies, petroleum oils, and salts.
2. Temperature resistance: Will soften at 100 8 F/388 C.
3. Limitations: Will be degraded by exposure to UV light and
weathering.
4. Applications: Usedo nsubmerged or buried steel and concrete.
8.5Z inc-Rich Paints
Zinc-rich paints owe their protection to galvanic action. Whereas all of the
preceding coatings owe their final film properties, corrosionresistance, and
environmental resistance to the composition of their resin or binderr ather
than their pigment, the highamount of zinc dust metal pigmentinzinc-rich
paints determines the coating’sf undamental property: galvanic protection.
Manyofthe previous coatings, chlorinated rubber and epoxies in particular,
Specific Organic Coatings
495
CAT8247—CHAPTER 8—17/10/2006—14:20—SRIDHAR—XML MODEL B–pp. 487–507
bricks and noncalcareous masonry.
8.4B ituminous Paints
There are two paints in this category: asphaltand coal tar.
8.4.1 Asphalt Paint
Asphalt paint consists of solids from crude oil refining suspended in
aliphatic solvents.
1. Resistance: Good moisture resistance; good resistance to weak
acids, alkalies, and salts; better weathering properties than coal tar.
2. Temperature resistance: Softensa t1 008 F/388 C.
3. Limitations:Heavy,d ark color hides corrosion under coating.
4. Applications: Used in above-groundw eathering environments
and chemical fume atmospheres.
8.4.2 Coal Tar
Coal tar is adistilled coking by-product in an aromatic solvent.
1. Resistance: Excellent resistance to moisture; good resistance to
weak acids and alkalies, petroleum oils, and salts.
2. Temperature resistance: Will soften at 100 8 F/388 C.
3. Limitations: Will be degraded by exposure to UV light and
weathering.
4. Applications: Usedo nsubmerged or buried steel and concrete.
8.5Z inc-Rich Paints
Zinc-rich paints owe their protection to galvanic action. Whereas all of the
preceding coatings owe their final film properties, corrosionresistance, and
environmental resistance to the composition of their resin or binderr ather
than their pigment, the highamount of zinc dust metal pigmentinzinc-rich
paints determines the coating’sf undamental property: galvanic protection.
Manyofthe previous coatings, chlorinated rubber and epoxies in particular,
Specific Organic Coatings
495
CAT8247—CHAPTER 8—17/10/2006—14:20—SRIDHAR—XML MODEL B–pp. 487–507