What Are The Different Types of Paints And Its Applications
Most of the materials required in building construction require a coating which is fulfilled by paints, varnishes, etc. Paint is a form of liquid which, on drying, forms a thin film on the substrate surface. The substrate can be concrete, wood, brick, plaster, metal, etc. It is applied in layers ranging from one to four layers to hide any imperfections of substrate wall and protecting from weathering action. Various types of paints are available in recent years with improved technology.
Applications and Uses of Paint :
- It can be applied on timber, brick or on any other materials.
- The main function of paint is to provide protection or decoration or both.
- Protect from weather, Sun, rain and makes it waterproof.
- Corrosion of Metals
- Mechanical stresses
- Paints conceal imperfections on the surface and gives surface protection.
- It increases life of the surface or product.
- It prevents wooden structures against warping, checking, or decay from termites, fungal growth, etc.
- Metals corrode if not painted at suitable intervals.
- Painting enables the masonry and concrete work to resist checking and disintegration, thereby extending life.
- It acts as a decoration and provides aesthetic value to the building.
- Paint modifies the reflection and transmission of light on a surface.
- Paints are also used as identifying any special equipment such as fire fighting lines are painted red to identify easily.
Qualities of good Paint
- Durable and long-lasting
- Ease of workability
- Surface coverage to be high with less usage of paint
- Uniform color and texture of paint on the applied surface
- Withstand weathering action making it waterproof
Composition of Paint
Paint is composed of base, pigment, organic binder and additives.
Pigment – Solid ingredient of paint and is used in the form of fine powder. Pigments provide color for the finished product. Provides film adhesion and protects the substrate from corrosion, weather, and abrasion. Its characteristics are Opacity, Color and Gloss.
Organic Binder – Liquid part of paint and it is called vehicle.
Additives – Modify the properties of the vehicle or pigment or both.
Commonly used Coatings:
- Applying the paint when the surface is dry is an essential factor to consider.
- A typical paint system consists of Primer and one or two top-coats. Primers are applied directly over the bare surface to improve adhesion of subsequent coats. Primer sealers and corrosion-resistant primers are commonly used type of primers.
- Fillers are used to fill and repair porous substrates before applying a paint material. Concrete block fillers for masonry surfaces and wood fillers for hardwoods are applied. Wall Putty acts as a filler or sealer.
- Varnishes and Lacquer are commonly referred as transparent finish.
Manufacture of Paints
- 1.Mix the basic ingredients in desired quantities.
- 2.Grinding the above mix of ingredients.
- 3.Thinning with solvent
Types of Paints
Type of paints vary based on solvents, application, sheen, etc.
Types of Paints Based on Solvent
- Water – Based Paints
- Oil – Based Paints
The solvent or binder used in water-based paints is almost water
- Low VOC’s emission
- Flexible and less susceptible to cracking
- More resistant to UV rays
- Can tolerate small amounts of moisture prior to application as it absorbs moisture.
- Takes less time to dry.
- Does not require a pre-treatment
- Stable color over time, doesn’t become yellow
- Lower sheen finish when compared to oil-based paints.
- Less tolerable to different variations in weather conditions.
Oil based paints use an organic solvent typically a mineral turpentine.
- Good for high moisture rooms.
- High durability and rich finish/sheen.
- Excellent resistance to wear and tear.
- More tolerant to differing weather conditions.
- Brushstrokes fill themselves-no strokes seen appearing smooth finish.
- Less flexible, likely to crack, become dry and brittle over time.
- High toxic emissions (VOC’s)may lead to health issues.
- If moisture is present on the surface, oil paints repel and does not create a strong bond.so the surface has to be completely dried.
- Take longer periods to dry.
- Turns yellow over time.
Types of Paints Based on Composition and Usage
They are water based paints and are most commonly used in interior surfaces. Distempers are oldest and cost effective paints. These paints have a distinctive odour composed of lime, chalk and water. They are easy to apply, durable, and generally gives a rustic finish compared to emulsion paints.
- Dry – It is available as dry powder and water is to added before applying.
- Synthetic – includes drying oils which help in increasing coverage area.
- Acrylic – It has acrylic co-polymer formulation
These paints are water-based paints and give a silken smooth finish with no odour. Expensive and durable than Distempers. Wide range of colors are available. It has scratch resistance and anti-fading properties.
Cement Based Paints
Type of water paint in which white or colored pigment and cement forms the base. Applied to exposed or plastered brick masonry and concrete work. It is weather proof.
Composed of cement, gypsum, sand, metal and binders. The coarse grains of gypsum and sand gives a rough texture to the wall. Distinct designs and style can be created with different kinds of textures.
In acrylic paints, pigments are suspended in acrylic polymer emulsion. These paints dry fast.
PU (Polyutharene) & Melamine
Protects timber from ultra-violet light and are durable with high resistance.
They are combinations of resins and oils/modified alkyd resins. Varnish helps to reveal wood grains thereby retaining natural wood color and enhancing it.
They are oil based paints. Made by adding pigments like white lead or zinc white to a binder which is varnish. Stand well with the adverse effects of atmosphere.
- General purpose
- Used for woodwork and metal surfaces.
- Made by mixture of aluminum powder and quick drying spirit varnish/slow drying oil varnish to suit requirements of surface.
- Weather resisting and waterproofing qualities, resistant to corrosive action of seawater.
- Mostly used for painting interior or exterior metallic surface, commonly applied on radiators.
- High reflective property.
- Used as a metal protection paint for preserving structural steelwork.
- Prevents from effect of acids, fumes, corrosive chemicals, resistant to rough weather conditions.
- Especially suitable for patchwork or stopping leakage in metal roofs.
- Used for painting gutters, flashings, etc. To prevent from rusting.
- Used for painting underwater structures, exterior brickwork and plastered surfaces.
- Alkali resistant and provide protection of iron and steel.
Rubber Base Paints
- The paint is made from rubber treated with chlorine gas which is dissolved in suitable solvents and mixed with other pigments.
- Excellent acid, alkali and moisture resistant properties. Commonly used as protective coating on cement concrete floors, interior or exterior masonry surfaces.
- Paint is made from celluloid sheets and amyl-acetate substitutes.
- Stands well with rough weather conditions.
- Hard, flexible and smooth.
- Due to its high costs, restricted to motor cars/vehicles.
- Casein is a protein substance extracted from milk curd which is mixed with a base consisting of white pigment.
- High opacity.
- Usually applied on walls, ceiling, wallboards, cement blocks to enhance the appearance of the surface.
Types of Paints Based on Finish/Sheen
- Low gloss and non-reflective finish (low gloss paint sheens absorb light).
- Mostly used for interior walls and ceilings of living, bedroom, dining, etc.
- Perfect for low traffic areas.
- Hides imperfections like chips or cracks in walls.
- Hard to clean handprints and other marks.
- Requires less no. of coats than glossy finishes.
- Low sheen, soft and velvety smooth like an eggshell.
- A kind of sheen between satin/glossy and gives a beautiful classic look.
- Perfect for low to mid traffic areas.
- Have little reflectivity.
- Provides pearl-like smooth and velvety finish.
- Easy to clean than low gloss finishes and resists chipping and peeling off.
- Works well in high traffic indoor areas.
- Reflect a bit of light.
- Shiny than satin finish, smooth and sleek.
- Less reflective than glossy finish and more reflective than matt and eggshell finishes.
- High resistant to moisture, suitable for high traffic areas.
- Bathrooms, kitchen cabinets, doors and windows etc.
- Highlight imperfections on walls.
Gloss Finish/High-Gloss Finish
- High reflective and glass-like finish (high gloss paints reflect light).
- Suitable for high traffic areas.
- Highlight imperfections on walls clearly.
- Common for furniture, cabinets, decorative trims, etc.
- Used on interior and exterior wooden moldings and metal surfaces.
Paints Application Method
Most common types of paints application methods are
- Painting with Brushes
- Spray Painting
- Roller Painting
Proper application of paints depends on several factor such as
- Surface Preparation
- Material selection
- Skill of the applicator
- Environmental Conditions
Commonly Used Paint Materials
- Paint – Easy to apply, often used on large and small wall surfaces. Flat, low-luster sheen.
- Enamel – Dries out fast, commonly used on small and smooth surfaces. Semi-gloss and High-gloss sheen.
- Stains – Generally used on wood surfaces, change the color of a surface and protect by penetrating the surface.
- Varnishes – Homogeneous mixtures of resins, oils, driers, and solvents.
- Lacquers – Dry quickly, film-forming solutions; mostly used on automobiles or furniture.