A paint primer is used as an undercoat to prepare the walls or ceilings before painting. It helps to seal the pores of the surface leading to using less of the final paint. Primer paint helps the final paint adhere better, increases its durability and provides a layer of protection to the drywall surface before painting it with a colour. It is also used to block stains and remove smoke odours.
In this article we explain the need and use for a paint primer, as well as the differences between the different primer paints.
What Is A Paint Primer
A paint primer is a preparatory coating or a foundation that is painted onto surfaces before painting a paint colour. It is made up of 20%-30% synthetic resin, 60%-80% solvent and 2%-5% additive agent, and some also contain a plastic called polyethylene for better durability, and created a sealed layer that helps any paint finish go on better.
When To Use A Primer Paint
A priming paint product is used on newly installed drywall (gyproc) in newly built homes, or in a home addition or renovation project where new dyrwall has been installed. The manufacturers of paint products will always recommend you apply one to two coats of paint primer, the DIY painters will almost always want to skip the primer as it will save them money and labour, while painting companies will recommend at least one coat.
A paint primer is always needed on porous surfaces. With newly installed drywall as it is a high porous surface so too is the dried compound used to cover the joint seams. If the drywall is not new and has been previously painted it may need repairs and patching before painting, thus it is recommended to use a primer over dark colours, over high gloss paints.
Using a paint primer over dark colours before painting with light paint colours is recommended. Painting a coat of primer paint over a dark colour before applying a light paint colour will save you from having to paint more than three to four coats of the light colour in order to get the best coverage. One coat of paint primer, and two coats of coloured paint is typically enough to get professional looking results.
If painting a dark colour over a light paint colour you can paint a white primer or have it tinted at your paint store to match the darker colour you will be using. This will help create the adhering factor for any paint to be applied and gives you good paint coverage and helps reduce the amounts of colour coats to paint.
It is also recommended to use a primer if painting over a glossy finish/sheen as glossy paints are formulated differently than most others and do not hold paint well. Therefore one to two coats of a primer first will ensure complete adhesion of any other paint finish and good coverage over the colour.
When Is Paint Primer Not Used
The times when a paint primer is not used would be if you have clean walls. If they are in good condition and clean of any grease or stains the need for a primer can be eliminated.
You can clean walls before painting with a cleaner called TSP. This cleaner can be found at paint stores or any home improvement stores. TSP removes dirt, grease, and grime that may have previously stained the surface to be painted. It can be used on interior walls or ceilings, and exterior wood such as decks and siding. You can also clean the walls with a vacuum brush, making sure all cobwebs and dust are removed. You may additionally want to wash the walls with some light dish soap and water.
Another instance when you may not need to use a primer is if you repainting the area with the same or very close to the same colour. For example if you have walls that are painted in a simply white and want to paint a fresh coat of the exact same colour, then there is no need to apply a coat of primer first. Unless you have done extensive drywall repairs. You would then need to prepare the walls for painting and would be better off applying a coat of primer.
You can also skip the primer if you use one of the all in one paint and primer products. Since all in one paints already have the primer and finish coat combined.
Why Is Paint Primer Used
Paint primers are used so that problems with paint such as peeling, flaking or bubbling are avoided. Primer paint can correct flaws and uneven surfaces, it creates a smooth and consistent layer to which the paint can be spread and adhere to and helps the final paint colour look better and last longer.
The Difference between A Paint Primer and the All In One Paints
The all in one paints or also known as self-priming paints and it is just paint that is thicker than regular paint. Although most DIY’ers have been lead to believe that using a all in one paint and primer will be faster, cheaper and less laborious. Professional painters do not use the all in one products. In the end it still requires the same amount of work but does not give the same professional end result. The difference between paint primer and all in one is that the colour and primer are mixed together in one. You will still need to apply at least 2 to 3 coats of the all in one to give you good coverage. Calculate the costs of painting and the cost of buying paint before deciding on which is the best for your next painting project.
More information can be found in the articles below about different types of paint products
Preparing Drywall for Painting
Water Based Paints vs Solvent Based Paints
The importance of preparation before painting
How a painting company can rip you off
Cracking or Flaking paint problems
Professional Painters Tips and Advice
This post was originally published on Jan 14, 2018 at 12:27 and edited on Feb 02, 2020 at 20:02