topic 3: coatings - participationandskills - home · web viewif you don’t use the correct coating...

Prepare Surfaces for PaintingCPCCPD3021A (D7385)

Topic 3:

Coatings

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ContentsIntroduction.................................................................................................................4What is Paint?..............................................................................................................4Paint Markets...............................................................................................................4Domestic & Commercial Paints....................................................................................5

Primers - Introduction.........................................................................................5Metal Primers - Functions....................................................................................5

Sacrificial Coatings.....................................................................................6Metal Primers - Types..........................................................................................7

Red Oxide / Metal Primer............................................................................7Zinc Rich Primer.........................................................................................7Metal Etch Primer.......................................................................................8Galvanised Iron Primer...............................................................................8

Wood Primers – Functions & Type.......................................................................8Pink/White Primer.......................................................................................9Red Lead Primer.........................................................................................9Acrylic Primer...........................................................................................10

Primers - Overall...............................................................................................11Sealers - Introduction........................................................................................11Sealers - Types..................................................................................................11

Water Based Sealers.................................................................................12Spirit Based Sealers..................................................................................12Oil Based Sealers......................................................................................12

Sealers - Overall................................................................................................13Undercoat - Introduction...................................................................................13Undercoat - Types.............................................................................................13

Oil Based Undercoat.................................................................................13Water Based Undercoat............................................................................14

Finish Coat - Introduction..................................................................................14Finish Coat - Types............................................................................................14

Oil Based Finish Coat................................................................................15Water Based Finish Coat...........................................................................15

Coating Systems........................................................................................................15Coating Systems - Examples.....................................................................................16Help – How to Read Coating System Tables..............................................................16

New Surfaces - Interior......................................................................................16 of 45

New Surfaces - Exterior.....................................................................................21Pre-Painted Surfaces - Interior..........................................................................24Pre-Painted Surfaces - Exterior..........................................................................27

Thickness Test...........................................................................................................29Wet Film Testing (WFT).....................................................................................29Dry Film Testing (DFT)......................................................................................30

Paint Inspection Gauge (PIG)....................................................................30Micrometre (Banana Gauge).....................................................................31

Painting Defects........................................................................................................32Painting Defects – Types............................................................................................32

Flaking & Peeling..............................................................................................33Blistering...........................................................................................................33Cracking or Crazing...........................................................................................34Moulds & Fungus...............................................................................................34Chalking or Fading............................................................................................35Efflorescence.....................................................................................................35Vanadium Staining............................................................................................35White Rust........................................................................................................36Loss of Gloss or Sinking....................................................................................36Flashing or Sheariness......................................................................................36Bleeding............................................................................................................37Grinning............................................................................................................37Cissing..............................................................................................................38Rain Spotting or Cratering.................................................................................38Runs, Sagging or Curtaining..............................................................................38

Conclusion.................................................................................................................39Credits - Funding.......................................................................................................39Credits - Images........................................................................................................39About the National VET E-learning Strategy..............................................................40

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IntroductionMain Painter: There are so many different types of paints!Helper Painter: To suit all kinds of surfaces and conditions. Not all paints are the same. Different types of paints, or coatings, are used in different situations.Main Painter: What do you mean?Helper Painter: For example, some coatings can only be used on specific surfaces or under certain conditions. If you don’t use the correct coating system, it may lead to problems with the work you’ve done.

What is Paint?Paint is a coloured liquid containing the following ingredients. Click on each ingredient to learn more:

PigmentPigments are either mined or manufactured. Their general appearance is similar to talcum powder when refined and are used to give paint its colour, opacity, body and provide UV protection.

BinderBinder can be an oil (e.g. linseed oil) or a resin. Oil paint resins are normally thick, shiny and honey-coloured. Other resins are manufactured chemically, designed for durability, water resistance and flexibility. The binder also holds the pigments together and adheres them to the surface.

SolventSolvents, also known as thinners, are used to dissolve resins or thin the coating to assist it being applied to a surface.Thinners also enable the coating to penetrate the substrate. On drying, it evaporates and leaves the coating.

DryerDryers are a mixture of cobalt, manganese and lead. They are commercially known as “Terebine”.They are added into oil-based paints to assist the binder to absorb oxygen and dry. Water and spirit based paints do not have dryers added as they dry by evaporation of their solvent.NOTE: Additional ingredients may include extender pigments (to give more body to the paint film); glycol or detergent (to break surface tension and assist

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spreading of paint); anti-foaming agents (to remove bubbles created by the glycol); and perfumes to improve the smell of paint.

Paint MarketsPaint is commonly used for the following markets:

Domestic & Commercial *These paints are suitable for houses and commercial buildings. They are easy to apply, and have a variety of finishes and colours.

IndustrialThese paints are highly durable, anti-corrosive, and have good covering qualities. They are suitable for extreme weather conditions. Anti-corrosive paints are also resistant to salt water, acid, alkali and water.

AutomotiveMade for the car industry, these paints are quick drying, have excellent durability and flexibility, good rematching qualities and good appearance.* For the purpose of this unit, we’ll be focusing on the Domestic & Commercial range of paints.

Domestic & Commercial PaintsThere are four main types of paint used in the domestic and commercial markets.Click on the following paints to learn more:

• Primer• Sealer• Undercoat• Finish Coat

Primers - IntroductionPrimers are usually used for metal and wood surfaces. They can:

• Provide a durable and protective coating which acts as a bridge between the surface and the paint system that follows.

• Satisfy the absorption of porous material, e.g. timber.• Provide adhesion on non-porous surfaces, e.g. zinc and aluminium.

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• Prevent the corrosion of ferrous metals and rotting of wood.

Metal Primers - FunctionsThe main functions of metal primers are:

• To gain adhesion to the metal – some metals are very smooth, and require primers specifically manufactured to adhere to these surfaces.

• To provide sacrificial protection against corrosion – most ferrous metal primers contain zinc. Metal primers act like a metal coating. Because some pigments (e.g. zinc) are higher on the galvanic series compared to the metal it is applied to (e.g. iron), they will protect the iron and sacrifice themselves if exposed to oxygen and water.

Sacrificial CoatingsWhen metals are exposed to the atmosphere, they are actually surrounded by an electrolyte (since the air contains water, dilute acids and salts) and corrosion occurs. This is especially common in industrial and coastal areas, where the atmosphere acts like a strong electrolyte; this explains why metals rust more rapidly in these areas.

Area Atmosphere Condition

Coastal Alkali Severe exposureIndustrial Sulphur Severe pollutionRural Normal Mild

Table 1 - Different geographical areas with separate columns for its location, its atmosphere properties and its condition.

Galvanic SeriesOne method of reducing corrosion is to apply a coating containing a metal which corrodes more rapidly than the substrate metal it is contact with. Metals are classified by their activity in the galvanic series.

Metal Activity

Aluminium Most unstable or active metals

ChromiumZincIronLead

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CopperSilverGold Most stable or noble metals

Table 2 - The Galvanic Series table showing the type of metal and its activity, listing (in order) the most unstable/active metals at the top and most stable/noble metals at the

bottom.

Metals at the top of the series are more active. If a coating containing a metal is applied to a substrate which is lower on the galvanic series, the metal in the coating will corrode rapidly, sacrificing itself for the substrate metal. Galvanising is the process of applying a zinc coating to iron to prevent corrosion.To protect metals against corrosion during the construction of buildings, ferrous metals are primed when they are fabricated (shaped) prior to leaving the factory.

Metal Primers - TypesClick on each type of metal primer below to learn more:

• Solvent Basedo Red Oxide / Metal Primer

o Zinc Rich Primer

o Metal Etch Primer

• Water Basedo Galvanised Iron Primer

Red Oxide / Metal PrimerExample:Dulux Professional Premium – Red Oxide Metal Primer

Type:Solvent based.

Properties:Red/brown or grey in colour.

Surfaces:May be used on all common ferrous metals.

Notes:Sometimes just referred to as a “metal primer”.

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Zinc Rich PrimerExample:Dulux Industrial – Metalshield Cold Galv

Type:Solvent based.

Properties:High zinc pigment content (up to 90%).

Surfaces:Used on prepared steel or as a ‘touch up’ primer for galvanised metal surfaces.

Metal Etch PrimerExample:Dulux Industrial – Metalshield Etch Primer

Type:Solvent based.

Properties:Formulated to etch and prime smooth metal surfaces where adhesion is a problem. The phosphoric acid in the primer slightly eats into the metal to roughen the smooth surface.

Surfaces:Mainly used on aluminium, copper, bronze, brass, zinc, lead and galvanised metals. Also used on prepared ferrous metals.

Notes:Sometimes known as “washed primers”.

Galvanised Iron PrimerExample:Dulux Quit Rust – All Metal Primer

Type:Water based.

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Surfaces:Used on all prepared galvanised surfaces. Can also be used on other metals (refer to manufacturer’s specifications).

Notes:• A metal pre-treatment should be applied for coatings exposed to extreme

conditions.• Do not apply when temperatures fall below 10°C as rain or dew will

damage the film during the drying period.

Wood Primers – Functions & TypeThe main functions of wood primers are:

• To satisfy the suction or the porosity of new, unpainted timber.• To protect against rot.• To seal sap stains.• To provide an ideal ‘key’ or base for following coats.

Click on each type of wood primer below to learn more:• Oil Based

o Pink/White Primer

o Red Lead Primer

• Water Basedo Acrylic Primer

Pink/White PrimerType:Oil based.

Properties:• Acts as a preservative.• Penetrates to provide an ideal base for following coats.• Excellent durability (as part of the complete system).• Dry film is non-toxic.• Provides a low gloss level (provides good hold out).

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Surfaces:Penetrates new, unpainted timber surfaces.

Notes:• By following manufacturer’s instructions, timber primers may be adjusted

to suit different timbers, e.g. hardwood vs. softwood.• This primer traditionally contained red lead, but is now tinted pink.

Red Lead PrimerType:Oil based.

Properties:• High concentration of lead; therefore very toxic.• Strong orange/red colour.

Surfaces:Prior to the 1980’s, this was used on both timber and metal surfaces.

Notes:• Care should be taken whenever removing old paint or when preparing old

surfaces. Strict guidelines for safety must be maintained when in contact with this coating.

• This primer is no longer manufactured due to lead content, but you will need to know about this primer for the purposes of this unit.

Please refer to the Occupational Health & Safety (OHS) topic for more information.

Acrylic PrimerExample:Dulux Professional Premium – Total Prep

Type:Water based.

Properties:• Formulated to seal open sap stains.• Used under acrylic and oil paint systems.• Quick drying, enabling same day recoating.

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• Good adhesion to properly prepared surfaces.• Dry film is non-toxic.• Tough flexible film.• Excellent chemical resistance.

Surfaces:Timber surfaces.

Notes:Apply using a brush or roller.

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Primers - OverallTypes of Primers Substrates

Timber

Metal(Ferrou

s)

Metal(Non-

Ferrous)Galvanise

d Iron

Red Lead # * *Red Oxide ^ *Zinc Chromate # * *Etch Primers (one and two pack) * *

Zinc Rich *Galvanised Iron *Pink/White Wood Primer *Acrylic Wood Primer *

Table 3 - Different types of primers and what substrates they can be painted on.

NOTE: ^ This primer is not suitable for galvanised surfaces. Other primers are specially made for galvanised metals.# Due to toxicity, these are no longer produced.

Sealers - IntroductionA sealer is used:

• To penetrate and provide adhesion.• To provide a barrier coat to prevent the penetration of alkali.• To satisfy the porosity of absorbent surfaces such as wallboards, masonry

and asbestos.• To bind powdery/chalky surfaces.• To prevent the bleeding of soluble stains into any following coats.

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Sealers - TypesThere are three main types of sealers. Click on each type of sealer to learn more:

• Water Based• Spirit Based• Oil Based

Water Based SealersSurfaces:

• New or previously painted masonry, gyprock, hardboard or timber surfaces.

• Ideal for sealing porous surfaces to prevent suction of subsequent coats.

Properties:• Fast drying.• Suitable for recoating of oil based paints.• Ideally formulated as part of an acrylic paint system.

Spirit Based SealersSurfaces:

• Surfaces that have a tendency to soften or bleed through after applying coats of paint.

• Bituminous, creosoted or water and smoke stained surfaces.

Properties:Can be used on previously painted surfaces that colours or inks bleed through.

Oil Based SealersExample:Dulux Prepcoat Sealer Binder (Oil Based)

Types:• Pigmented sealers• Binding sealers

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Pigmented:Pigmented sealers are used to seal porous surfaces and prevent alkali attack on subsequent coats. It is used for interior and exterior surfaces such as set plaster, masonry, cement, plaster glass, bricks, etc.

Binding:Binding sealers are intended for binding thin powdery films of kalsomine or chalky paint to the original surface to form a sound basis for further painting. Can be used on all types of interior and exterior surfaces provided that thick layers of kalsomine or chalky paint are first washed off, leaving a thin penetrable layer.

Sealers - OverallTypes of Sealers Substrates

Masonry Plasterboard Plaster

Oil Based Sealer – Pigmented (alkaline resistant) * *

Oil Based Sealer – Binding (alkaline resistant) * *

Water Based Sealer * *Table 4 - Different types of sealers and what substrates they can be painted on.

Undercoat - IntroductionUndercoats have the following properties and functions:

• Have good adhesion to the primer or sealer.• Provide good opacity.• Have good flow and levelling properties.• Provide satisfactory film build and filling properties.• Provide ‘key grip’ for the following coat.• Provide good sanding properties.

Undercoat - TypesThere are two main types of undercoat. Click on each type to learn more:

• Oil Based

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• Water Based

Oil Based UndercoatExample:Dulux Professional Premium – Oil Based Undercoat

Surfaces:• Any primed or sealed surface.• Interior and exterior.

Properties:• Heavily pigmented material.• Designed to be used under gloss paints.• Dries to a low gloss finish.

Water Based UndercoatExample:Dulux Professional Premium – Total Prep

Surfaces:• Correctly primed or previously painted timber.• Directly over new or previously painted masonry, hardboard, etc.• Can be applied to any primed or sealed surface.

Properties:• General purpose.• Quick drying.

Finish Coat - IntroductionFinish coats are the final coats of paint applied to a surface. Their functions are to:

• Protect the surface from weather, chemical attack and abrasion.• Decorate to appear pleasing to the eye.• Provide texture to a surface.• Provide colour to identify and label surfaces or to convey a message.

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• Enable the surface to be cleaned easily.

Finish Coat - TypesThere are two main types of finish coat. Click on each type of finish coat to learn more:

• Oil Based• Water Based

Oil Based Finish CoatExamples:

• Dulux Professional Premium – Semi Gloss Enamel Interior• Dulux Professional Premium – Full Gloss Enamel Interior/Exterior

Sheen Levels:• Flat• Semi Gloss / Satin• Gloss

Water Based Finish CoatExamples:

• Dulux Professional Premium – Flat Interior Acrylic• Dulux Professional Premium – Semi Gloss Interior/Exterior Acrylic• Dulux Professional Premium – Gloss Exterior Acrylic

Sheen Levels:• Flat• Matt• Low Sheen• Semi Gloss / Satin• Gloss

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Coating SystemsA coating system is the application of:

• A primer or sealer• An undercoat• Top coats

Coating systems are used because it is too difficult to apply a paint film of sufficient thickness in one operation to give the required appearance and performance.Examples of coating systems in different scenarios can be found in the Guide to the Painting of Buildings (AS/NZS 2311:2009). You can purchase this document at www.standards.org.au.

Coating Systems - ExamplesCoating systems can be categorised by surface type and location.

New Surfaces• Interior• Exterior

Pre-Painted Surfaces• Interior• Exterior

NOTE: The following coating systems are based on correct trade standards in Australia. However, due to technological advances in paint formulation, variations of these systems are possible.

Help – How to Read Coating System TablesThe following tables show examples of coating systems that you can use based on the type of substrate, surface and location you’re dealing with.NOTE: For multiple columns, you have a choice between the different types of coatings, but the subsequent coats in the same column must follow through.

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http://www.standards.org.au/

New Surfaces - InteriorTimber:

Paint

Oil Based

Coating System

1st coat Oil based wood primer2nd coat Oil based undercoat Oil based semi-gloss3rd coat Oil based gloss Oil based semi-gloss

Water Based

Coating System

1st coat Water based wood primer

2nd coat Water based undercoat Water based semi-gloss

3rd coat Water based gloss Water based semi-glossTable 5 - Example coating system for painting new interior timber surfaces, with separate

rows to indicate the type of coating system, number of coats, and the type of coatings.

Varnish

Oil Based

Coating System

Wood stain (if required)

1st

coat

Oil based varnish flat

Oil based varnish semi-gloss

Oil based varnish gloss

2nd

coat




3rd

coat




Water Based

Coating System


1st

coat

Water based varnish flat

Water based varnish semi-gloss

Water based varnish gloss

2nd

coat




3rd

coat




Table 6 - Example coating system for varnishing new interior timber surfaces, with separate rows to indicate the type of coating system, number of coats, and the type of

coatings.

Plywood / Hardboards / Particle Boards:Paint

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Oil Based

Coating System

1st coat Oil based primer2nd coat Oil based undercoat Oil based semi-gloss3rd coat Oil based gloss Oil based semi-gloss

Water Based

Coating System

1st coat Water based primer

2nd coat Water based undercoat Water based semi-gloss

3rd coat Water based gloss Water based semi-glossTable 7 - Example coating system for painting new interior plywood/hardboard/particle board surfaces, with separate rows to indicate the type of coating system, number of

coats, and the type of coatings.

Varnish

Oil Based

Coating System


1st

coat




2nd

coat




3rd

coat




Water Based

Coating System


1st

coat




2nd

coat




3rd

coat




Table 8 - Example coating system for varnishing new interior plywood/hardboard/particle board surfaces, with separate rows to indicate the type of coating system, number of

coats, and the type of coatings.

Brick / Set Plaster / Plaster Glass:Paint

Oil Based

Coating System

1st

coat Oil based sealer

2nd

coatOil based undercoat Oil based semi-gloss

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3rd

coat Oil based gloss Oil based semi-gloss

Water Based

Coating System

1st

coat Oil based sealer

2nd

coatWater

based flatWater based

low sheenWater based semi-gloss

Water based gloss

3rd

coatWater



Water based gloss

Table 9 - Example coating system for painting new interior brick/set plaster/plaster glass surfaces, with separate rows to indicate the type of coating system, number of coats, and

the type of coatings.

Gypsum Plasterboard (Gyprock):Paint

Oil Based

Coating System

1st

coat

Water based sealer

2nd

coat

Oil based undercoat Oil based semi-gloss

3rd

coat

Oil based gloss Oil based semi-gloss

Water Based

Coating System

1st

coat

Water based sealer

2nd

coat

Water based flat

Water based low sheen

Water based semi-gloss

Water based gloss

3rd

coat

Water based flat



Water based gloss

Table 10 - Example coating system for painting new interior gyprock surfaces, with separate rows to indicate the type of coating system, number of coats, and the type of

coatings.

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Galvanized Iron / Zincalume:Paint

Oil Based

Coating System

1st coat Oil based metal primer / Galvanized iron primer2nd

coat Oil based undercoat Oil based semi-gloss

3rd coat Oil based gloss Oil based semi-gloss

Water Based

Coating System

1st coat Galvanized iron primer2nd

coatWater



Water based gloss

3rd coat Water based flat



Water based gloss

Table 11 - Example coating system for painting new interior galvanized iron/zincalume surfaces, with separate rows to indicate the type of coating system, number of coats, and


Aluminium / Copper / Brass:Paint

Oil Based

Coating System

1st coat Etch primer2nd coat Oil based undercoat Oil based semi-gloss3rd coat Oil based gloss Oil based semi-gloss

Water Based

Coating System

1st coat Etch primer

2nd coat Water based flat



Water based gloss

3rd coat Water based flat



Water based gloss

Table 12 - Example coating system for painting new interior aluminium/copper/brass surfaces, with separate rows to indicate the type of coating system, number of coats, and


Iron / Steel:Paint

Oil Based Coatin

g Syste

m

1st

coat

Oil based metal primer

2nd

coat


3rd

coat


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Table 13 - Example coating system for painting new interior iron/steel surfaces, with separate rows to indicate the type of coating system, number of coats, and the type of

coatings.

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Polystyrene:Paint

Water BasedCoatin

g Syste

m

1st

coat

Water based primer

2nd

coat

Water based flat



Water based gloss

3rd

coat

Water based flat



Water based gloss

Table 14 - Example coating system for painting new interior polystyrene surfaces, with separate rows to indicate the type of coating system, number of coats, and the type of

coatings.

PVC:Paint

Water Based

Coating System

1st

coat

Water based flat



Water based gloss

2nd

coat

Water based flat



Water based gloss

Table 15 - Example coating system for painting new interior PVC surfaces, with separate rows to indicate the type of coating system, number of coats, and the type of coatings.

New Surfaces - ExteriorTimber:

Paint

Oil Based Coatin

g System

1st

coat

Oil based wood primer

2nd

coat

Oil based gloss

3rd

coat

Oil based gloss

Water Based

1st

coaWater based wood primer

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Coating

System

t2nd

coat

Water based gloss Water based semi-gloss

3rd

coat

Water based gloss Water based semi-gloss

Table 16 - Example coating system for painting new exterior timber surfaces, with separate rows to indicate the type of coating system, number of coats, and the type of

coatings.

Varnish

Oil Based

Coating System

1st

coat

Oil based exterior varnish gloss

2nd

coat


3rd

coat


Water Based

Coating System

1st

coat

Water based exterior varnish semi-gloss

Water based exterior varnish gloss

2nd

coat



3rd

coat



Table 17 - Example coating system for varnishing new exterior timber surfaces, with separate rows to indicate the type of coating system, number of coats, and the type of

coatings.

Brick / Stucco / Plaster:Paint

Water Based Coatin

g System

1st

coat



Water based gloss

2nd

coat



Water based gloss

Table 18 - Example coating system for painting new exterior brick/stucco/plaster surfaces, with separate rows to indicate the type of coating system, number of coats, and


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Cement Render & Sheeting:Paint

Water Based Coatin

g System

1st

coat



Water based gloss

2nd

coat



Water based gloss

Table 19 - Example coating system for painting new exterior cement render & sheeting surfaces, with separate rows to indicate the type of coating system, number of coats, and


Iron / Steel:Paint

Oil Based

Coating System

1st

coat Oil based metal primer

2nd

coat Oil based gloss

3rd


Water Based

Coating System

1st

coat Oil based metal primer

2nd

coatWater



Water based gloss

3rd

coatWater



Water based gloss

Table 20 - Example coating system for painting new exterior iron/steel surfaces, with separate rows to indicate the type of coating system, number of coats, and the type of

coatings.

Galvanized Iron / Zincalume:Paint

Oil Based

Coating System

1st

coat

Oil based metal primer / galvanized iron primer

2nd

coat

Oil based gloss

3rd

coat

Oil based gloss

Water 1st Galvanized iron primer

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Based Coating System

coat

2nd

coat

Water based flat



Water based gloss

3rd

coat

Water based flat



Water based gloss

Table 21 - Example coating system for painting new exterior galvanized iron/zincalume surfaces, with separate rows to indicate the type of coating system, number of coats, and


Aluminium / Copper / Brass:Paint

Oil Based

Coating System

1st

coat

Etch primer

2nd

coat

Oil based undercoat

3rd

coat

Oil based gloss

Water Based

Coating System

1st

coat

Etch primer

2nd

coat

Water based flat



Water based gloss

3rd

coat

Water based flat



Water based gloss

Table 22 - Example coating system for painting new exterior aluminium/copper/brass surfaces, with separate rows to indicate the type of coating system, number of coats, and


PVC:Paint

Oil Based Coatin

g Syste

m

1st

coat

Oil based gloss

2nd

coat

Oil based gloss

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Water Based Coatin

g Syste

m

1st

coat

Water based flat



Water based gloss

2nd

coat

Water based flat



Water based gloss

Table 23 - Example coating system for painting new exterior PVC surfaces, with separate rows to indicate the type of coating system, number of coats, and the type of coatings.

Concrete:Paint

Oil Based Coatin

g Syste

m

1st

coat

Paving paint low sheen Paving paint gloss

2nd

coat

Paving paint low sheen Paving paint gloss

Table 24 - Example coating system for painting new exterior concrete surfaces, with separate rows to indicate the type of coating system, number of coats, and the type of

coatings.

Pre-Painted Surfaces - InteriorWalls & Ceilings (with oil based paint on surface):

Paint

Oil Based Coatin

g Syste

m

1st

coat


2nd

coat


Water Based Coatin

g Syste

m

1st

coat

Water based semi-gloss Water based gloss

2nd

coat


Table 25 - Example coating system for painting pre-painted interior walls & ceilings with an oil based paint on surface, with separate rows to indicate the type of coating system,

number of coats, and the type of coatings.

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Walls & Ceilings (with oil based varnish on surface):Varnish

Oil Based Coatin

g Syste

m

1st

coat

Oil based varnish semi-gloss Oil based varnish gloss

2nd

coat


Table 26 - Example coating system for varnishing pre-painted interior walls & ceilings with an oil based varnish on surface, with separate rows to indicate the type of coating

system, number of coats, and the type of coatings.

Walls & Ceilings (with water based paint on surface):Paint

Oil Based Coatin

g Syste

m

1st

coat


2nd

coat


Water Based Coatin

g Syste

m

1st

coat

Water based flat



Water based gloss

2nd

coat

Water based flat



Water based gloss

Table 27 - Example coating system for painting pre-painted interior walls & ceilings with a water based paint on surface, with separate rows to indicate the type of coating


Walls & Ceilings (with water based varnish on surface):Varnish

Water Based Coatin

g Syste

m

1st

coat

Water based varnish semi-gloss Water based varnish gloss

2nd

coat


Table 28 - Example coating system for varnishing pre-painted interior walls & ceilings with a water based varnish on surface, with separate rows to indicate the type of coating


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Doors, Frames, Windows & Skirting (with oil based paint on surface):

Paint

Oil Based Coatin

g Syste

m

1st coat Oil based undercoat Oil based semi-gloss

2nd coat Oil based gloss Oil based semi-gloss

Water Based Coatin

g Syste

m

1st coat Water based undercoat2nd coat Water based semi-gloss Water based gloss

3rd coat Water based semi-gloss Water based gloss

Table 29 - Example coating system for painting pre-painted interior doors, frames, windows & skirting with an oil based paint on surface, with separate rows to indicate the

type of coating system, number of coats, and the type of coatings.

Doors, Frames, Windows & Skirting (with oil based varnish on surface):

Varnish

Oil Based

Coating System

1st

coat


2nd

coat


Table 30 - Example coating system for varnishing pre-painted interior doors, frames, windows & skirting with an oil based varnish on surface, with separate rows to indicate

the type of coating system, number of coats, and the type of coatings.

Doors, Frames, Windows & Skirting (with water based paint on surface):

Paint

Oil Based

Coating System

1st

coat


2nd

coat


Water Based

Coating System

1st

coat


2nd Water based semi-gloss Water based gloss of 45

coat

Table 31 - Example coating system for painting pre-painted interior doors, frames, windows & skirting with a water based paint on surface, with separate rows to indicate


Doors, Frames, Windows & Skirting (with water based varnish on surface):

Varnish

Water Based

Coating System

1st

coat


2nd

coat


Table 32 - Example coating system for varnishing pre-painted interior doors, frames, windows & skirting with a water based varnish on surface, with separate rows to indicate


Pre-Painted Surfaces - ExteriorWalls & Eaves (with oil based paint on surface):

Paint

Water Based

Coating System

1st

coat

Oil based undercoat (omit if sanded well)

2nd

coat

Water based

flatWater based


Water based gloss

3rd

coat

Water based

flatWater based


Water based gloss

Table 33 - Example coating system for painting pre-painted exterior walls & eaves with an oil based paint on surface, with separate rows to indicate the type of coating system,

number of coats, and the type of coatings.

Walls & Eaves (with water based paint/texture on surface):Paint

Water Based

Coating System

1st

coat

Water based

flatWater based


Water based gloss

2nd

coaWater based



Water based gloss

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t flatTable 34 - Example coating system for painting pre-painted exterior walls & eaves with a water based/texture paint on surface, with separate rows to indicate the type of coating


Pergola, Patios & Decking (with oil based varnish on surface):

Varnish

Oil Based

Coating System

1st

coat Oil based varnish gloss

2nd


Table 35 - Example coating system for varnishing pre-painted exterior pergola, patios & decking with an oil based varnish on surface, with separate rows to indicate the type of

coating system, number of coats, and the type of coatings.

Pergola, Patios & Decking (with water based varnish on surface):

Varnish

Water Based

Coating System

1st

coatWater based varnish

semi-gloss Water based varnish gloss

2nd

coatWater based varnish

semi-gloss Water based varnish gloss

Table 36 - Example coating system for varnishing pre-painted exterior pergola, patios & decking with a water based varnish on surface, with separate rows to indicate the type of

coating system, number of coats, and the type of coatings.

Doors, Frames, Windows & Weatherboards (with oil based paint on surface):

Paint

Oil Based Coatin

g Syste

m

1st

coat Oil based undercoat

2nd


3rd


Water Based Coatin

g Syste

m

1st

coat Oil based undercoat

2nd

coat Water based semi-gloss Water based gloss

3rd

coat Water based semi-gloss Water based gloss

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Table 37 - Example coating system for painting pre-painted exterior doors, frames, windows & weatherboards with an oil based paint on surface, with separate rows to

indicate the type of coating system, number of coats, and the type of coatings.

Doors, Frames, Windows & Weatherboards (with oil based varnish on surface):

Varnish

Oil Based

Coating System

1st


2nd


Table 38 - Example coating system for varnishing pre-painted exterior doors, frames, windows & weatherboards with an oil based varnish on surface, with separate rows to


Doors, Frames, Windows & Weatherboards (with water based paint on surface):

Paint

Oil Based Coatin

g Syste

m

1st coat Oil based undercoat2nd coat Oil based gloss

3rd coat Oil based gloss

Water Based Coatin

g Syste

m

1st coat Water based gloss

2nd coat Water based gloss

Table 39 - Example coating system for painting pre-painted exterior doors, frames, windows & weatherboards with a water based paint on surface, with separate rows to


Doors, Frames, Windows & Weatherboards (with water based varnish on surface):

Varnish

Water Based Coatin

g Syste

m

1st

coatWater based varnish semi-

gloss Water based varnish gloss

2nd

coatWater based varnish semi-

gloss Water based varnish gloss

Table 40 - Example coating system for varnishing pre-painted exterior doors, frames, windows & weatherboards with a water based varnish on surface, with separate rows to


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Thickness TestCoatings applied to surfaces provide protection from the environment and the elements. If not applied according to the manufacturer’s specifications, the coating could break down. Thickness testing is more common in industrial paint application. Manufacturers specify coating thickness in “microns” on their Product Data Sheets.There are two methods of determining the thickness of a paint coating. Click on the testing methods to learn more:

• Wet Film Testing (WFT)• Dry Film Testing (DFT)

Wet Film Testing (WFT)Purpose:To measure the thickness of a paint coating while still wet.

Surfaces:Can be used on any surface.

Tools:Wet film gauge.

Method:1. Immediately after applying the coating, place one side of the gauge to the

surface. Use the side with the lowest numbers first. Ensure the two outer feet firmly touch the surface.

2. Remove the gauge and check if all the teeth have paint on them. If so, wipe off the paint with a clean rag.

3. Turn the gauge to the next successive side and repeat process until one or more of the teeth remain clean.

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Readings:Observe the numbers above the tooth with paint, followed by the tooth without paint. Find the average between the two readings. The measurement represents the thickness of the coating in microns (µm), e.g. 127.5µm.

Dry Film Testing (DFT)Purpose:To measure the thickness of a paint coating after it has dried.

Tools:• Paint Inspection Gauge (PIG)• Micrometre (Banana Gauge)

Paint Inspection Gauge (PIG)Surfaces:Can be used on any surface.

Method:1. Place gauge with feet and diagonally positioned metal knives firmly on the

surface.2. Drag gauge over surface to cut the coating. 3. Turn on the gauge’s light, and place it over the cut surface.4. Observe a magnified view of the cut surface through the eyepiece.5. Note the measurement markings and line it up with the cut made. Take a

reading of each coating.

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Readings:The measurement represents the thickness of the coating in microns (µm).

Magnified View of Eyepiece:

Micrometre (Banana Gauge)Surfaces:Only magnetic surfaces.

Method:1. Apply gauge to metal surface with feet and magnetic arm housing placed

firmly on the surface.2. Turn the dial on the top of the gauge clockwise so that the magnetic arm

inside the housing is lifted off the surface. The brass indicator on top of the gauge should be sticking out.

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3. Turn the dial anti-clockwise until the magnetic arm attaches itself to the surface and the dial cannot be turned anymore. The brass indicator should now be sitting low.

4. Turn the dial clockwise again until you hear a click, indicating the magnetic arm is disconnected from the surface.

5. Note the reading on the side of the dial.

Readings:The measurement represents the thickness of the coating in microns (µm), e.g. 140 µm.

Video:Watch this video demonstrating how to use a micrometre.

Painting DefectsThe professional painter and decorator must be able to identify common painting defects in order to:

• Ensure quality work by maximising life of the coating system• Avoid incorrect diagnosis which can lead to premature breakdown of

the paint film and costly rectification• Gain the confidence of clients. If the contractor is unable to determine

the cause of the problem, this may be interpreted as unprofessional.

Painting Defects – Types• Flaking & Peeling• Blistering• Cracking or Crazing

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https://www.youtube.com/watch?v=YGWjdabpLqg

• Moulds & Fungus• Chalking or Fading• Efflorescence• Vanadium Staining• White Rust• Loss of Gloss or Sinking• Flashing or Sheariness• Bleeding• Grinning• Cissing• Rain Spotting or Cratering• Runs, Sagging or Curtaining

Flaking & PeelingBreakdown of adhesion resulting in paint or varnish lifting away from the surface in flakes.

Causes Preventions

Painting damp surfaces, especially wood.

Use a moisture meter to ensure that timber is dry.

Painting in humid conditions which promote condensation.

Do not paint in foggy, wet or frosty conditions.

Expansion and shrinkage of painted surfaces.

Select paints to suit nature of surface.

Lack of adhesion on smooth, shiny surfaces.

Wash and abrade the surface.

Formation of rust under paintwork. Ensure thorough preparation and use of a suitable primer.

Efflorescence forming under the paint film.

Remove all efflorescence by dry brushing before painting.

Table 41 - Causes and preventions for flaking and peeling.

BlisteringEruption of a paint or varnish film forming bubbles on the surface.

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Causes Preventions

Trapped moisture in wood made worse by heat, especially dark colours.

Use a moisture meter to ensure that timber is dry.

Resin exuding from knots due to heat or sunlight.

Seal knots prior to painting.

Trapped moisture in plaster or rendering.

Use permeable coatings or wait until surface is dry.

Using non-heat resistant paints adjacent to sources of extreme heat.

Use heat resistant paint. Light colours have more resistance to blistering by heat than dark colours.

Table 42 - Causes and preventions for blistering.

Cracking or CrazingSplitting of the surface due to the top coat of paint or varnish being unable to expand to the same degree as the previous coatings.

Causes Preventions

Applying hard drying coatings over soft, elastic coatings.

Choose correct paint system.

Recoating before undercoat has dried. Allow specified drying time before recoating.

Adding excessive driers. Add only the minimum amount of driers.

Paste and size over new paintwork. Remove all paste and size from paintwork immediately after paperhanging.

Table 43 - Causes and preventions for cracking or crazing.

Moulds & FungusMulti-coloured spots or patches on infected areas.

Causes Preventions

A variety of air-borne spores which multiply and feed on the organic matter in paints, papers, pastes and surface deposits.

Promoted by dampness

Trace and remedy cause of dampness.Remove mould and fungus by scraping and washing.Sterilise area with a proprietary fungicidal solution or three to one ratio (3:1) mixture of water and household bleach.

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and poor ventilation.Common in bathrooms, laundries, bakeries,

Observe for seven days for any reappearance of mould.Coat with paints containing a fungicide.

Table 44 - Causes and preventions for moulds and fungus.

Chalking or FadingFormation of a powdery deposit on the surface of the dry paint film, the powder being unbound pigment.

Causes Preventions

Paint deficient in binder due to over thinning.

Thin paints only when specified.

Prolonged exposure in sunlight.Painting insufficiently sealed on absorbent surfaces.

Seal absorbent surfaces and touch up filling.

Highly pigmented bright and dark paints with exterior exposure.

Correct choice of paint.

Use of interior paints on exposed surfaces.


Table 45 - Causes and preventions for chalking or fading.

EfflorescenceWhite, powdery deposit that forms on the surfaces of porous building materials such as bricks, mortar and concrete.

Causes Preventions

Paint deficient in binder due to over thinning.

Thin paints only when specified.

Prolonged exposure in sunlight.Painting insufficiently sealed on absorbent surfaces.


Highly pigmented bright and dark paints with exterior exposure.


Use of interior paints on exposed surfaces.


Table 46 - Causes and preventions for efflorescence.

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Vanadium StainingA green, yellow or reddish brown stain exuded from clay bricks. On painted brickwork it can be unsightly. If brickwork is painted without prior treatment, the stain may reappear and eventually breakdown the paint film.

Causes Preventions

Light coloured clays often contain traces of vanadium which appear on new brickwork as it is drying out.

Apply alkali resistant oil based sealer to prevent bleeding.

Table 47 - Causes and preventions for vanadium staining.

White RustWhite rust is actually zinc carbonisation of zincalume and galvanised iron, appearing as a fine white powder on the surface.

Causes Preventions

Zinc carbonisation is a natural process and evident on surfaces when insufficient coats have been applied.

They often appear on substrates painted with darker colours, as they are more likely to have less coats applied to achieve coverage.

All galvanised iron and zincalume surfaces should have an appropriate coating system of one priming of etch coat, one coat of oil based undercoat, followed by at least one finish coat.

Table 48 - Causes and preventions for white rust.

Loss of Gloss or SinkingFailure of paint or varnish to maintain its potential or original sheen or shine.

Causes Preventions

Painting insufficiently sealed absorbent surfaces.


Use of wrong paint system. Use correct primers and undercoats.Paint applied and temperature drops below manufacturer’s specifications.

Plan the work so that paint will dry in correct conditions.

Over thinning of product. Thin to manufacturer’s specifications.Wet paint film affected by damp weather or condensation.

Plan the work so that paint will dry in correct conditions.

Table 49 - Causes and preventions for loss of gloss or sinking.

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Flashing or ShearinessPatches of uneven sheen on flat or eggshell finishes.

Causes Preventions

Edge sets before overlapping of joins on ceilings, large wall areas or guttering.

Increase the number of painters in order to cover the work quicker or provide a running scaffold for guttering.

High room temperatures cause rapid setting.

Reduce room temperature. Use additives to slow drying.

Swift air movement accelerates drying process.

Close windows and doors during application to cut down air movement.

Application over too porous surfaces causes uneven sinkage.

Apply over well sealed and undercoated surfaces only.

Table 50 - Causes and preventions for flashing or sheariness.

BleedingDiscolouration of the finishing paint by some dissolvable matter on the surface being coated.

Causes Preventions

Painting surfaces coated with bitumen, oils and nicotine. Biro and spirit pens will also penetrate water based paints.

Use correct sealer.

Painting surfaces or paints containing lake pigments or dyestuffs.

Use correct sealer.

Painting knotty or resinous woods. Use shellac or correct sealer.Table 51 - Causes and preventions for bleeding.

GrinningThe previous surface colour shows through the finish coat.

Causes Preventions


Use correct sealer.

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Use correct sealer.

Painting knotty or resinous woods. Use shellac or correct sealer.Table 52 - Causes and preventions for grinning.

CissingThe paint or varnish coating film rolls back into globules, leaving small round bare patches.

Causes Preventions


Use correct sealer.


Use correct sealer.

Painting knotty or resinous woods. Use shellac or correct sealer.Table 53 - Causes and preventions for cissing.

Rain Spotting or CrateringCraters in the surface of a dry paint film.

Causes Preventions

Rain spots falling on the surface of the wet film.

Avoid painting exposed work when it is likely to rain.

Droplets of condensation on the wet paint film.

Avoid painting in damp or humid conditions.

Heavy dew forming on the wet paint film.

Paints should be applied so that they will be ‘touch dry’ before dew starts to fall. Plan your work so paint will dry in correct conditions.

Table 54 - Causes and preventions for rain spotting or cratering.

Runs, Sagging or CurtainingUneven paint film flows down the vertical surface along which wrinkling usually follows.

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Causes Preventions

Uneven application. Even application.Paint runs from the corners of mouldings and ornamental work or projections.

Avoid heavy coats on such areas.

A wet edge starts to set and when joined or lapped, the paint runs.

Plan the work so that the wet edge is kept open. Check over work to remove runs whilst applying.

Table 55 - Causes and preventions for runs, sagging or curtaining.

ConclusionMain Painter: So I guess… “paints ain’t paints”, right?Helper Painter: You said it! Remember, not all paints are the same, so you must be careful with what you use.

Credits - FundingThis project was made possible through funding from the National VET E-learning Strategy 2012-2015, a joint initiative of the Australian and state and territory governments (http://flexiblelearning.net.au).For further information on the National VET E-learning Strategy, please contact the FLAG Secretariat:

Phone: (03) 9954 2700 Email: [email protected] Website: flexiblelearning.net.au

Topic 3: Coatings (Prepare Surfaces for Painting), © Commonwealth of Australia (Department of Industry, Innovation, Climate Change, Science, Research and Tertiary Education), 2013. (http://creativecommons.org/licenses/by/3.0/au)

Credits - ImagesAll images of ‘Dulux’ products were used with permission from DuluxGroup. Disclaimer: All images of branded products were used for illustrative purposes only. Please note that other brands are available for purchase in your line of work.All other images used in this resource are owned by Polytechnic West. © Polytechnic West 2013

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mailto:[email protected]


Information within this resource was current at 2013.

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About the National VET E-learning Strategy This project was made possible through funding from the 2012-2015 National VET E-learning Strategy (‘the Strategy’). The Strategy is a joint initiative of the Australian and state and territory governments aimed at strengthening the Australian training sector’s use of new learning technologies; stimulating innovative approaches to increasing participation in training and employment, and improving the skill levels of the Australian workforce (http://flexiblelearning.net.au).

For further information on the National VET E-learning Strategy, please contact the FLAG Secretariat:

Phone: (03) 9954 2700

Email: [email protected]

Website: flexiblelearning.net.au

Topic 1: Surfaces (Prepare Surfaces for Painting), © Commonwealth of Australia (Department of Industry, Innovation, Climate Change, Science, Research and Tertiary Education), 2013.

With the exception of the Commonwealth Coat of Arms, the Department’s logo, any material protected by a trade mark and where otherwise noted all material presented in this document is provided under a Creative Commons Attribution 3.0 Australia (http://creativecommons.org/licenses/by/3.0/au/) licence.

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