Do I need Primer before Paint? – A Guide
If you are beginning a paint project, you will typically start evaluating which coating you may use and then learn more about applying the given coating and what if any paint application equipment makes sense. One key step in determining a proper coating will be to determine if you need primer before paint or can you use a primer/ paint combination instead. Choosing improperly can result in issues with coating performance including even coating failure. While the following tips will help you, you should always coordinate with your paint representative to ensure that the solution your considering will work.
Drywall
If you are painting new build drywall it has a tendency to absorb a lot of coating which can create issues in producing a consistent coating build across the surface. It can also easily result in high volumes of coating being used. For new drywall using a primer first will help reduce the total costs of painting as primer is generally less expensive than paint and will help provide a smooth consistent coating while reducing paint use.
Aluminum Siding
If the bare metal of the siding is exposed due to wear of the existing coating on the siding or any other reason you will typically want to consider a primer. If the metal is not exposed you do not have to use a primer though using a primer will help in ensuring a uniform coating appearance.
Wood
Unfinished wood is typically porous and without a primer to properly fill In the pores of the wood the finish coat of paint will appear less smooth. So for unfinished wood you should consider using a primer first as this will provide a smooth base for the finish coat to be applied to which will help provide a better final finish appearance. Common options for wood primers include latex base and oil based, the best one for you will typically depend on the wood your finishing and should be determined by consulting your coating provider.
Metal
If you are painting a metal surface that has rust or exposed metal you will typically want to consider a primer. Without a primer the surface will rust or rust further if already rusted. If the metal surface is already painted and the underlying paint is in good condition you often do not need a primer. This is a general overview and you should always confirm with a coatings provider to ensure that your particular application will not need a primer for proper coating performance. Metal can include a variety of applications that often will have special coating requirements and is why you should speak with your coating company to ensure they do not have additional or different recommendations as metal can have strong protective requirements depending on where it will go.
Masonry
Masonry projects may require a primer but it will often depend on the ph of the mason substrate as well as any concerns you may have with efflorescence which is white deposits that can sometimes form on masonry. If the masonry is a high ph and/or you want to ensure you reduce the risk of efflorescence you will usually need to consider a primer. Without a proper primer with a high PH substrate there is greater risk for coating failure. Similarly, primers often are what help provide protection against efflorescence with brick substrates.
Covering Up Stains
If you have a stain in an area of your home from water damage, smoke exposure, or any reason at all a primer will be more effective at properly concealing the stain then paint alone. Without properly priming the stain before applying paint you can have issues where the stain appears through the paint after application.
Significant Changes in Paint Color
If you will be significantly shifting to a new color (especially a light color over a dark color) primer will help ensure that the new color will not take excessive applications to achieve the proper appearance.
Tough Surfaces to Bond
Certain surfaces can be challenging to have a coating adhere to. Common surfaces that can be hard to achieve good adhesion include glazed surfaces, tile, and plastics. In these situations, a primer can provide adhesion that the finish coat of paint will then be able to properly bind to. This will help reduce the likelihood of issues with coating failure.
Additional Details
When choosing a primer, you want to ensure that the primer is designed for the surface you will be painting over. Some primers come in a multi-use format and you will want to verify that they can be used with your surface. Additionally, if you are considering a paint and primer in one you will want to check with the coating provider to determine if they are effective as well as if they will provide similar quality and durability when your painting is finished as using a primer that is separate from your paint.
By considering these steps, you can better determine if a primer before your paint will help provide a better end result. You can also check out the additional resources below for more information.
Additional resources
Do You Need a Metal Paint Primer