What is Primer Paint | Types of Primer used in Construction

What is Primer Paint?

Prior to the finish coat of paint, a specific kind of paint called a primer is applied. Primers serve as the base for your paint job and can be applied to plasterboard, wood, metal and concrete. Primer ensures that the painting surface has the right, homogeneous texture (slightly coarse) so that paint adheres properly, whether you’re painting interior or exterior surfaces. Primers also stop stains and previous colours from showing through your paint job by sealing up porous surfaces. After you’ve patched up holes and fixed damage, they also aid in levelling out walls.

While painted surfaces can be painted over without priming, it is typically preferable to prime so that your work is as strong and long-lasting as possible. Priming is required if you’re switching paint kinds while working on painted surfaces. For instance, changing the color scheme drastically or converting from oil-based to latex-based paints and vice versa. Priming can also fix any issues with your paint job (after you’ve done repairs and prepared the surface) if paint is chipping, crumbling, or if there is surface damage.

For interior surfaces, external surfaces, metals, and in particular hues, primers are created. Interior primer provides a homogeneous surface for walls and other surfaces, enhances adhesion, and seals. Exterior primers reduce the likelihood of cracking and mildew growth while shielding masonry surfaces against efflorescence and alkalinity. There are many formulations of exterior primers available for use on metal, masonry, or wood. Metal primers prevent corrosion and offer a strong bond between the surface and topcoat. Tinted primers enhance the final product of your painting project by enhancing colour highlights and enhancing the finish coat colour for a better-looking job.

Types of Primer

1. Oil Based Primer

Oil-based Primers made can be applied both inside and outside. It is mostly used to work with wood, including dry wood, new wood, and painted wood. It can also be applied to metal surfaces.

Alkyd primer is another name for oil-based primer. Both latex and oil-based paints will work with this primer. A final coat of paint film will either expand or contract as a result of temperature changes, and an oil-based primer will typically continue to be flexible after drying.

Therefore, the oil-based primer’s feature of being temperature-sensitive is particularly useful.

Mineral spirits are needed for cleaning and thinning, but they are excellent at creating barriers to stop the wood from bleeding through.

Good “Stain Killers” like oil-based primers keep stains from showing through your fresh coats of paint. They work well in preventing ink, nicotine, and water stains on your walls.

Advantages of Oil-Based Primer

• A flexible surface that is provided by oil-based primer helps prevent paint coats from expanding or contracting as a result of temperature changes.
• They stop stains from penetrating the fresh coats of paint.
• An oil-based primer is applied to wood to help seal the porous surface and stop tannins from leaking through the paint.
• Unfinished, previously varnished, and severely aged wood can all be painted with oil-based primer.

Disadvantages of Oil-Based Primer

• Significant amounts of volatile organic compounds (VOCs) are produced by oil-based primers, necessitating a well-ventilated work area and protective gear when applying them.
• They require more than 24 hours to dry completely.
• They are challenging to remove from painting tools.
• Applying oil-based primers straight on masonry will not work.

2. Latex-based Primer

Water-based latex primers are perfect for preparing unfinished plasterboard for painting. They are less brittle, more flexible, and quick to dry than oil-based primers, which makes them less likely to peel and split. They work well for priming galvanised metals, masonry, concrete, and softwoods like pine.

Because they level out the surface of the wallboard, any joint compound that has been applied to it, and any places that have been patched or mended, latex primers are suitable for plasterboard. They are less adept at concealing stains than oil- and shellac-based primers, but they can still cover and seal in prior light stains from smoke, lipstick, crayon, etc.

These primers may be easily cleaned because they are water-soluble. They are a healthier option to oil-based and shellac primers because they are also available in low- or no-VOC compositions.

Advantages of Latex Primers

• Latex primers are more flexible than oil-based primers and dry faster than oil-based primers, often in 3 to 4 hours.
• Latex primers can smooth out the surface and cover mended areas.
• Latex primers provide a healthy environment and don’t produce any volatile organic chemicals.
• Since latex primers are water-based, it is simple to remove them from tools or paint supplies.
• Compared to oil-based primers, latex primers offer a more durable paint surface.

Disadvantages of Latex Primers

The main drawbacks of a latex primer are staining and inadequate surface coverage.
For surfaces made of metal and timber, latex primer is not recommended.
The exceptional fracture resistance of latex primers.

3. Shellac Primer

The most popular primers for interior painting projects are of this type. These do a great job of protecting walls from stains, serious water damage, and smoke damage. It can be utilized with plastic, plaster, metal, wood, etc. Surfaces are painted with oil or latex paint that has been blended with shellac primer.

Advantages of Shellac Primer

• Compared to other primers, shellac primer dries quickly and is very sticky; it takes only one hour to dry.
• To stop obstinate tannin bleeding, pitch pockets, and wood knots, use shellac primer.
• It offers excellent stain resistance.

Disadvantages of Shellac Primer

• The main drawback of Shellac primers is that they are less adaptable than latex or oil primers and that they emit more toxic fumes.
• They need to be thinned with denatured alcohol (tinner), and the applicators need to be cleaned.