how to select the right paint system - cio … to select the right paint system guidelines for...

HOW TO SELECT THE RIGHT PAINT

SYSTEM

GUIDELINES FOR COATING PROTECTION IN

ACCORDANCE WITH ISO 12944

What is Corrosion?

• Corrosion is the gradual destruction of materials,

usually metals, by chemical reaction with its

environment. In the most common use of the word,

this means electrochemical oxidation, of metals in

reaction with an oxidant such as oxygen. Rusting,

the formation of iron oxides, is a well-known

example of electrochemical corrosion.

How to prevent corrosion?

• 1. Barrier effect

• 2. Inhibitor effect

• 3. Galvanic effect

1. Barrier effect:

• Paints with very low water permeability.

• Bitumen, Tar or Epoxy at High DFT

• Flake formed pigments – Low DFT

• Parallel orientation of flakes, Complicated

and longer path around pigments.

2. Inhibitor effect:

Primers containing Inhibitors to suppress

corrosion process.

Water soluble

Top Coated with Barrier Product

Not suited for prolonged immersion

3. Galvanic effect:

Protection of steel through the galvanic effect (Cathodic

protection)

Paint containing large amounts of metallic zinc.

Metallic contact between the zinc particles and the steel.

Absolutely clean steel surface

Zinc silicates, are initially rather porous.

Pores are filled and a barrier is formed.

Not suited immersion service

Favoured protection in solvent tanks.

ESTABLISH THE EFFECT OF ENVIROMENTAL

CORROSIVITY BY CONSIDERING:

• HUMIDITY AND TEMPERATURE (SERVICE TEMPERATURE

AND TEMPERATURE GRADIENTS)

• THE PRESENCE OF UV RADIATION

• CHEMICAL EXPOSURE (eg. SPECIFIC EXPOSURE IN

INDUSTRIAL PLANTS)

• MECHANICAL DAMAGE ( IMPACT, ABRASION ETC)

• BURRIED STRUCTURES, POROSITY & GROUND CONDITIONS

• DAMPNESS, Ph & BIOLOGICAL EXPOSURE

• CHEMICAL COMPOSITION OF WATER

THE CORROSIVE AGGRESSIVENESS OF THE

ENVIROMENT WILL HAVE AN EFFECT ON:

• TYPE OF PAINT USED FOR PROTECTION

• TOTAL THICKNESS OF A PAINT SYSTEM

• THE SURFACE PREPARATION REQUIRED

• MINIMUM AND MAXIMUM RECOATING INTERVALS

• THE MORE CORROSIVE THE ENVIRONMENT, THE MORE

THOROUGH THE SURFACE PREPARATION REQUIRED

• RECOATING INTERVALS MUST ALSO BE STRICTLY

OBSERVED.

5 BASIC CATEGORIES RELATING TO

ATMOSPHERIC CORROSION

CORROSIVITY CATEGORY ENVIRONMENT EXAMPLES

EXTERIOR INTERIOR

C1

VERY LOW -

HEATED BUILDINGS WITH A

CLEAN ATMOSPHERE SUCH AS

OFFICES, SHOPS, SCHOOLS,

HOTELS.

C2

LOW

ATMOSPHERE CONTAMINATED TO A

SMALL EXTENT, MAINLY RURAL

REGIONS.

BUILDINGS WHICH ARE NOT

HEATED, WHERE CONDENSATION

MAY OCCUR E.G. STOREHOUSES,

SPORTS HALLS.

C3

MEDIUM

INDUSTRIAL AND URBAN

ATMOSPHERE WITH AN AVERAGE

SULPHUR OXIDE (IV) CONTAMINATION

LEVEL. INSHORE AREAS OF LOW

SALINITY.

PRODUCTION SPACE OF HIGH

HUMIDITY AND CERTAIN AIR

CONTAMINATION E.G. FOODSTUFF

PLANTS, LAUNDRIES,

BREWERIES, DAIRIES.

C4

HIGH

INDUSTRIAL AREAS AND INSHORE

AREAS OF MEDIUM SALINITY.

CHEMICAL PLANTS, SWIMMING

POOLS, SHIP REPAIR YARDS.

C5-I

VERY HIGH

(INDUSTRIAL)

INDUSTRIAL AREAS OF HIGH

HUMIDITY AND AGGRESSIVE

ATMOSPHERE.

BUILDINGS AND AREAS OF

ALMOST CONSTANT

CONDENSATION AND HIGH

CONTAMINATION.

C5-M

VERY HIGH

(MARINE)

INSHORE AREAS AND OFFSHORE

AREAS OF HIGH SALINITY.

BUILDINGS AND AREAS OF

ALMOST CONSTANT

CONDENSATION AND HIGH

CONTAMINATION.

THE CATEGORIES FOR WATER AND SOIL

CORROSIVITY CATEGORIES ENVIRONMENT EXAMPLES OF ENVIRONMENTS AND

STRUCTURES

IM1 FRESH WATER RIVER INSTALLATIONS,

HYDROELECTRIC POWER PLANTS

IM2 SEA OR BRACKISH WATER

SEAPORTS WITH THE FOLLOWING

STRUCTURES: SLUICE GATE, LOCKS

(WATER STEPS), WATER STILTS,

PIERS, OFFSHORE STRUCTURES

IM3 SOIL UNDERGROUND TANKS, STEEL

STILTS, PIPELINES

THE TYPE OF SURFACE TO

BE PROTECTED

• STEEL, HOT DIPPED GALVANIZED STEEL, SPRAY-

METALIZED STEEL, ALUMINIUM OR STAINLESS STEEL.

• THE PAINT PRODUCTS USED (PARTICULARLY THE

PRIMER)

• TOTAL SYSTEM THICKNESS

THE DURABILITY REQUIRED FOR A

PAINT SYSTEM

• THE LIFETIME OF A PAINT SYSTEM IS ASSUMED TO BE THE

PERIOD OF TIME WHICH PASSES UNTIL MAINTENANCE IS

REQUIRED FOR THE FIRST TIME AFTER APPLICATION.

LOW – L 2 to 5 years

MEDIUM – M 5 to 15 years

HIGH - H more than 15 years

Planning the paint application process

• BUILDING SCHEDULE, VARIOUS STAGES OF

CONSTRUCTION, DETERMINE HOW AND WHEN

APPLICATION TAKES PLACE

• PREFABRICATED BOTH OFF AND ON SITE AND WHEN

BUILDING STAGES ARE COMPLETE.

• SURFACE PREPARATION AND THE CURING TIME OF PAINT

PRODUCTS IN RELATION TO TEMPERATURE AND HUMIDITY

ARE CONSIDERED.

• WORKSHOP/SITE, RECOATING INTERVALS MUST ALSO BE

TAKEN INTO ACCOUNT.

SURFACE PREPARATION

STANDARD SURFACE PREPARATION GRADES FOR PRIMARY SURFACE PREPARATION

BY ABRASIVE BLASTING METHODS

Sa 3

BLAST-CLEANING TO VISUALLY CLEAN STEEL

WHEN VIEWED WITHOUT MAGNIFICATION, THE SURFACE SHALL BE FREE FROM VISIBLE

OIL, GREASE AND DIRT, AND SHALL BE FREE FROM MILL SCALE, RUST, PAINT COATINGS

AND FOREIGN MATTER. IT SHALL HAVE A UNIFORM METALLIC COLOUR.

Sa 2 ½

VERY THOROUGH BLAST-CLEANING


OIL, GREASE AND DIRT, AND FROM MILL SCALE, RUST, PAINT COATINGS AND FOREIGN

MATTER. ANY REMAINING TRACES OF CONTAMINATION SHALL SHOW ONLY AS SLIGHT

STAINS IN THE FORM OF SPOTS OR STRIPES.

Sa 2

THOROUGH BLAST-CLEANING


OIL, GREASE AND DIRT, AND FROM MOST OF THE MILL SCALE, RUST, PAINT COATINGS AND

FOREIGN MATTER1. ANY RESIDUAL CONTAMINATION SHALL BE FIRMLY ADHERING.

Sa 1

LIGHT BLAST-CLEANING


OIL, GREASE AND DIRT, AND FROM POORLY ADHERING MILL SCALE, RUST, PAINT

COATINGS AND FOREIGN MATTER.

SURFACE PREPARATION

STANDARD PREPARATION GRADES FOR PRIMARY SURFACE PREPARATION

BY HAND & POWERTOOL CLEANING

St 3

VERY THOROUGH HAND AND POWER TOOL CLEANING

AS FOR ST 2, BUT THE SURFACE SHALL BE TREATED MUCH MORE

THOROUGHLY TO GIVE A METALLIC SHEEN ARISING FROM THE METALLIC

SUBSTRATE.

St 2

THOROUGH HAND AND POWER TOOL CLEANING

WHEN VIEWED WITHOUT MAGNIFICATION, THE SURFACES SHALL BE FREE

FROM VISIBLE OIL, GREASE AND DIRT, AND FROM POORLY ADHERING MILL

SCALE, RUST, PAINT COATINGS AND FOREIGN MATTER.

WATER JETTING

Wa 1

LIGHT HIGH-PRESSURE WATER JETTING

WHEN VIEWED WITHOUT MAGNIFICATION, THE SURFACE SHALL BE FREE FROM VISIBLE OIL AND

GREASE, LOOSE OR DEFECTIVE PAINT, LOOSE RUST AND OTHER FOREIGN MATTER. ANY RESIDUAL

CONTAMINATION SHALL BE RANDOMLY DISPERSED AND FIRMLY ADHERENT.

Wa 2

THOROUGH HIGH-PRESSURE WATER JETTING

WHEN VIEWED WITHOUT MAGNIFICATION, THE SURFACE SHALL BE FREE FROM VISIBLE OIL,

GREASE AND DIRT AND MOST OF THE RUST, PREVIOUS PAINT COATINGS AND OTHER FOREIGN

MATTER. ANY RESIDUAL CONTAMINATION SHALL BE RANDOMLY DISPERSED AND CAN CONSIST OF

FIRMLY ADHERENT COATINGS, FIRMLY ADHERENT FOREIGN MATTER AND STAINS OF PREVIOUSLY

EXISTENT RUST.

Wa 2½

VERY THOROUGH HIGH-PRESSURE WATER JETTING

WHEN VIEWED WITHOUT MAGNIFICATION, THE SURFACE SHALL BE FREE FROM ALL VISIBLE RUST,

OIL, GREASE, DIRT, PREVIOUS PAINT COATINGS AND, EXCEPT FOR SLIGHT TRACES, ALL OTHER

FOREIGN MATTER. DISCOLORATION OF THE SURFACE CAN BE PRESENT WHERE THE ORIGINAL

COATING WAS NOT INTACT. THE GREY OR BROWN/BLACK DISCOLORATION OBSERVED ON PITTED

AND CORRODED STEEL CANNOT BE REMOVED BY FURTHER WATER JETTING.

L

LIGHT FLASH RUST

A SURFACE WHICH, WHEN VIEWED WITHOUT MAGNIFICATION, EXHIBITS SMALL QUANTITIES OF A

YELLOW/BROWN RUST LAYER THROUGH WHICH THE STEEL SUBSTRATE CAN BE SEEN. THE RUST

(SEEN AS A DISCOLORATION) CAN BE EVENLY DISTRIBUTED OR PRESENT IN PATCHES, BUT IT WILL

BE TIGHTLY ADHERENT AND NOT EASILY REMOVED BY GENTLE WIPING WITH A CLOTH.

M

MEDIUM FLASH RUST

A SURFACE WHICH, WHEN VIEWED WITHOUT MAGNIFICATION, EXHIBITS A LAYER OF

YELLOW/BROWN RUST THAT OBSCURES THE ORIGINAL STEEL SURFACE. THE RUST CAN BE

EVENLY DISTRIBUTED OR PRESENT IN PATCHES, BUT IT WILL BE REASONABLY WELL ADHERENT

AND IT WILL LIGHTLY MARK A CLOTH THAT IS GENTLY WIPED OVER THE SURFACE.

H

HEAVY FLASH RUST

A SURFACE WHICH, WHEN VIEWED WITHOUT MAGNIFICATION, EXHIBITS A LAYER OF RED-

YELLOW/BROWN RUST THAT OBSCURES THE ORIGINAL STEEL SURFACE AND IS LOOSELY

ADHERENT. THE RUST LAYER CAN BE EVENLY DISTRIBUTED OR PRESENT IN PATCHES AND IT WILL

READILY MARK A CLOTH THAT IS GENTLY WIPED OVER THE SURFACE.

MAXIMUM SERVICE TEMPERATURES:

HEMPEL PAINTS / GENERIC TYPES

HEMPEL OFFERS THE FOLLOWING MAIN TYPES OF

PAINT:

- ONE COMPONENT:

A) ALKYD

B) ACRYLIC

C) POLYSILOXANE (FOR HIGH TEMPERATURE

SERVICE)

- TWO COMPONENTS:

A) EPOXY (PURE AND MODIFIED)

B) POLYURETHANE

C) ZINC SILICATE

D) POLYSILOXANE HYBRIDS

CORROSIVITY CATEGORIES

• C1/C2 CORROSIVITY CATEGORY

• C3 CORROSIVITY CATEGORY

• C4 CORROSIVITY CATEGORY

• C5-I CORROSIVITY CATEGORY

• C5-M CORROSIVITY CATEGORY

• IMMERSED STRUCTURES

• HEAT RESISTANT STRUCTURES

C1 / C2 CORROSIVITY CATEGORY:

Lifetime System No Paint Type Hempel Paint System Samples Thickness (micron)

0-5 Years

1

SB Alkyd 1x HEMPAQUICK PRIMER 13624 40

SB Alkyd 1x HEMPAQUICK ENAMEL 53840 40

Total DFT 80 μm

2

WB Alkyd 1x HEMULIN PRIMER 18310 40

WB Alkyd 1x HEMULIN ENAMEL 58380 40

Total DFT 80 μm

3 SB Polyurethane 1x HEMPATHANE HS 55610 80

Total DFT 80 μm

Lifetime System No Paint Type Hempel Paint System Samples Thickness (micron)

5-15 Years

1



Total DFT 120 μm

2



Total DFT 120 μm

3 SB Epoxy 1x HEMPADUR MASTIC 45880 120

Total DFT 120 μm


Total DFT 120 μm

C1 / C2 CORROSIVITY CATEGORY:

Lifetime

> 15 Years

System No Paint Type Hempel Paint System Samples Thickness

(micron)

1



Total DFT 160 μm

2



Total DFT 160 μm

3

WB Acrylic 2x HEMUCRYL PRIMER HB 18032 120

WB Acrylic 1x HEMUCRYL ENAMEL HB 58030 40

Total DFT 160 μm


Total DFT 160 μm

5

SB Epoxy 1x HEMPADUR QUATTRO 17634/

HEMPADUR 17410 100

SB Polyurethane 1x HEMPATHANE HS 55610 60

Total DFT 160 μm

6

WB Epoxy 1x HEMUDUR 18500 100

WB Polyurethane 1x HEMUTHANE ENAMEL 58510 60

Total DFT 160 μm

C3 CORROSIVITY CATEGORY:

Lifetime System No Paint Type Hempel Paint System Samples Thickness

(micron)

0-5 Years

1



TOTAL DFT: 120µm

2



TOTAL DFT: 120µm


TOTAL DFT: 120µm


TOTAL DFT: 120µm


(micron)

5-15 Years

1

WB Acrylic 1x HEMUCRYL PRIMER HB 18032 100

WB Acrylic 1x HEMUCRYL ENAMEL HB 58030 60

TOTAL DFT: 160µm

2

SB Epoxy 1x HEMPADUR 17410 100


TOTAL DFT: 160µm

3



TOTAL DFT: 160µm

C3 CORROSIVITY CATEGORY:


(micron)

>15 Years

1

WB Acrylic 2x HEMUCRYL PRIMER HB

18032 140

WB Acrylic 1x HEMUCRYL ENAMEL HB

58030 60

TOTAL DFT: 200µm

2



TOTAL DFT: 200µm

3


WB Polyurethane 1x HEMUTHANE ENAMEL

58510 60

TOTAL DFT: 200µm

4

SB Zinc Epoxy 1x HEMPADUR ZINC 17360 40



TOTAL DFT: 160µm

C4 CORROSIVITY CATEGORY Lifetime System No Paint Type Hempel Paint System Samples

Thickness

(micron)

0-5 Years

1

WB Epoxy

2x HEMUCRYL PRIMER HB 18032 140

WB Polyurethane 1x HEMUCRYL ENAMEL HB 58030 60

TOTAL DFT: 200µm


TOTAL DFT: 200µm


(micron)

5-15 Years

1



TOTAL DFT: 240µm

2



TOTAL DFT: 240µm

3




TOTAL DFT: 200µm

4

WB Zinc Epoxy 1x HEMUDUR ZINC 18560 60



TOTAL DFT: 200µm

C4 CORROSIVITY CATEGORY

Lifetime System No Paint Type Hempel Paint System

Samples

Thickness

(micron)

>15 Years

1



TOTAL DFT: 280µm

2




TOTAL DFT: 240µm

4

WB Zinc Epoxy 1x HEMUDUR ZINC 18560 60


WB Polyurethane 1x HEMUTHANE ENAMEL

58510 60

TOTAL DFT: 240µm

5

SB Zinc Silicate 1x HEMPEL's GALVOSIL

15700 60

SB Epoxy 1x HEMPADUR MASTIC

45880 120

SB Polyurethane 1x HEMPATHANE HS 55610

60

TOTAL DFT: 240µm



Samples

Thickness

(micron)

5-15 Years

1 SB EPOXY

2x HEMPADUR QUATTRO

17634 300

TOTAL DFT: 300μm

2

SB ZINC EPOXY 1x HEMPADUR ZINC

17360 60

SB EPOXY 1x HEMPADUR 17410 120

SB POLUYRETHANE 1x HEMPATHANE HS

55610 60

TOTAL DFT: 240μm

3

WB ZINC EPOXY 1x HEMUDUR ZINC 18560 60

WB EPOXY 2x HEMUDUR 18500 120

WB POLUYRETHANE 1x HEMUTHANE ENAMEL

58510 60

TOTAL DFT: 240μm



Samples

Thickness

(micron)

>15 Years

1

SB EPOXY 2x HEMPADUR MASTIC

45880 260

SB POLYURETHANE 1x HEMPATHANE HS

55610 60

TOTAL DFT: 320μm

2


17360 60



55610 60

TOTAL DFT: 320μm

3




58510 60

TOTAL DFT: 320μm

4

SB INORGANIC ZINC

SILICATE

1x HEMPEL's GALVOSIL

15700 60


45880 200


55610 60

TOTAL DFT: 320μm

C5 M CORROSIVITY CATEGORY


Samples

Thickness

(micron)

5-15 Years

1 SB EPOXY

2x HEMPADUR MASTIC

45880 300

TOTAL DFT: 300µm

2


WB POLYURETHANE 1x HEMUTHANE ENAMEL

58510 40

TOTAL DFT: 280µm

3

SB ZINC EPOXY 1x HEMPADUR ZINC 17360 40


SB POLUYRETHANE 1x HEMPATHANE HS 55610 80

TOTAL DFT: 240µm

4




58510 60

TOTAL DFT: 240µm

C5M CORROSIVITY CATEGORY Lifetime System No Paint Type

Hempel Paint System

Samples

Thickness

(micron)

>15 Years

1


45880/W 260


55610 60

TOTAL DFT: 320µm

2


17360 60



55610 60

TOTAL DFT: 320µm

3




58510 60

TOTAL DFT: 320µm

4

SB INORGANIC ZINC

SILICATE

1x HEMPEL's GALVOSIL

15700 60


45880 200


55610 60

TOTAL DFT: 320µm

IMMERSED STRUCTURES


(micron)

5-15 Years

1

Epoxy HEMPADUR QUATTRO 17634 160


TOTAL DFT: 320µm

2

Epoxy HEMPADUR MASTIC 45880 160

Epoxy HEMPADUR MASTIC 45880 160

TOTAL DFT: 320µm

3

Epoxy GF HEMPADUR MULTI-STRENGTH

GF 35870 400

TOTAL DFT: 400µm

1. For Steel Structures immersed in water (excluding potable water) or buried in soil

IMMERSED STRUCTURES


(micron)

>15 Years

1




TOTAL DFT: 500µm

2

Epoxy HEMPADUR MULTI-STRENGTH

45751/3 150


45751/3 175


45751/3 175

TOTAL DFT: 500µm

3


GF 35870 300


GF 35870 300

TOTAL DFT: 600µm

4 Epoxy HEMPAUDR 87540 800

TOTAL DFT: 800µm

IMMERSED STRUCTURES


Samples Thickness (micron)

5 - 15 Years

1

Epoxy (solvent free) HEMPADUR 35560 200

Epoxy (solvent free) HEMPADUR 35560 200

TOTAL DFT: 400µm

2

Epoxy

(solvent free) HEMPADUR 35560 400

TOTAL DFT: 400µm

2. For Steel Structures immersed in potable water (drinking water)

Paint Type Hempel Paint System Sample Thickness (micron)

Epoxy (Phenolic) HEMPADUR 85671 100



TOTAL DFT: 300µm

3. Tanklining for fuels (Crude oil, Jet fuel, Gasoline etc.)

3. Tanklining for fuels (Crude oil, Jet fuel, Gasoline etc.)

HEAT RESISTANT STRUCTURES


Zinc Silicate HEMPEL’S GALVOSIL 15780 75

Silicon HEMPEL'S SILICONE ALUMINIUM 56910 25


TOTAL DFT: 125µm





TOTAL DFT: 125µm

Paint Type Sample Hempel Paint System Thickness (micron)

Zinc Silicate HEMPEL’S GALVOSIL 15700 80

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