Type of paint 5

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Level 2 Diploma in Painting and Decorating

Type of paint

Unit 216: Applying paint systems by brush and roller to complex areas



Learning outcomes •  Understand how to prepare and apply waterborne and solventborne

coating by brush and roller, in line with manufacturers' instructions, to complex areas.

•  Be able to prepare and apply waterborne and solventborne coatings by brush and roller to complex areas in line with manufacturers' instructions.

•  Understand the properties of paint coatings.


Level 2 Diploma in Painting and Decorating Surface coatings Paint is a pigmented or coloured liquid, used to preserve, decorate, sanitize and identify.

Stain is semi-transparent and a varnish is transparent – they are used to enhance the beauty of the timber grain in hardwoods.

The classification of coatings are generalised as waterborne and solventborne.



Primers and sealers The primer or sealer coat on a new surface is the base of the paint system. The coating combines with the surface material to form a key with that surface. The paint mechanically grips the surface. If the primer is incorrect, the durability of the paint system will be reduced. Functions of a primer: 1. Provides a base for the paint system to adhere to (stick). 2. Helps to protect the surface. 3. Evens out porosity. 4. Seals the surface. 5. Forms a barrier between the surface and subsequent paint system. Research the types of primers available for timber, plaster and metal.



Stains

Decorative stains are available in a variety of types. They are used to enhance the beauty of the timber grain in hardwoods. They can be used on softwoods and building boards of certain types, and can be used by specialist decorators to imitate the grain of timbers. Oil-based interior wood stains have pigment in a mixture of resin/solvent, like oil paints. These take a long time to completely dry – up to 24 hours. Water-based interior wood stains are similar to latex paint in that they have pigment in a resin/water mixture. Unlike oils, these stains do not take much time to dry. Opaque stains These stains are used for general work such as the protection of fences, garden sheds etc. They are high build.


Level 2 Diploma in Painting and Decorating Varnishes Varnishes are clear coatings which offer a hard, chemical-resistant protective layer over stains and some paints. Varnishes are either very hard and brittle, or soft and elastic. Finishes: matt, satin and gloss. Polyurethane varnishes are typically hard, abrasion-resistant and durable coatings. Alkyd varnishes are chemically modified vegetable oils that operate well in a wide range of conditions. Acrylic varnishes are waterborne, quick drying and do not yellow. Discuss in groups the types of varnishes available for use.



Types of primers Solventborne Plaster – alkaline-resistant primer Timber – aluminium wood primer, universal primer Timber boards – aluminium wood primer, universal primer Metal – zinc phosphate, etch, red oxide, micaceous iron oxide Waterborne Plaster – thinned emulsion, acrylic, resin-based combined primer Timber – acrylic primer Timber boards – thinned emulsion, acrylic primer Metal – acrylic metal primer



Undercoats An undercoat is the coating that offers high build to the paint system; it also has good covering power due to the high pigmentation levels in the paint make-up (obliterates) – the undercoat adheres to the primer key coat.

Discuss in groups the types of undercoats available for use.

A high solid – like alkyd interior undercoat –demonstrates excellent coverage, grip and sealing properties. May be top coated with either latex or alkyd finishes.



Undercoats

•  Latex paint is non-toxic and has less odour than other paints, such as oil-based paint.

•  When used indoors, fumes from oil-based paint may

linger for several weeks. •  On the other hand odours from latex paint dissipate

quickly after the paint has dried. •  However, adequate ventilation is always necessary

when painting indoors, regardless of the type of paint used.



Finishes There are many different types of interior paint finishes. Flat and matt paint finishes have no real sheen when the paint has dried. Rather than reflect light, flat and matt paint finishes absorb it. Both paint finishes are good for hiding small surface imperfections and imperfections in application. Silk emulsion is an attractive high sheen paint with light reflecting properties, making it the ideal choice if you want to make a room look bigger. It is washable, making it ideal for kitchens and bathrooms.



Finishes An eggshell paint is a mid sheen but has a tiny amount of sheen to it when dried.

It is a good choice for interior walls and washes slightly better than flat wall paint (available in water and oilborne).



Finishes A satin paint finish is often the glossiest paint finish a decorator will recommend for any room apart from the kitchen and bathroom. It is not a high-gloss finish but has a smooth, velvety shine when dry.

Satin paint finishes do not hide imperfections in surfaces or application as well as matt finishes.



Finishes

High gloss paint finishes are at the other end of the spectrum and reflect the most light of any paint finish when dried. High gloss is a great choice for high traffic areas and exterior areas.

Image reproductions courtesy of Decorating Warehouse and Axminster.



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Type of paint 5