Paint primers are not always necessary in every painting project.  To know when you should use a primer you first have to:

  • understand what types of primers are available 
  • what they’re intended to be used for. 

The best way to understand their intended uses is to first look at them by primer categories.

Drywall Primer

New/bare drywall soaks up paint like a sponge. Consequently this causes it to cover better in some areas than others. This is especially true when you’re comparing drywall mud joints to the surrounding areas. To help achieve a consistent appearance with your final coat it is always a good idea to first use a paint primer. Besides, using a quality drywall primer is typically much less expensive per gallon than using multiple coats of a quality interior latex paint.

Wood Primer

Bare wood is among the more difficult substrates for a paint topcoat to adhere to.  In the past, there was no substitute for a good slow-drying, oil-based, primer on bare wood.  It takes a long time to dry. You must allow for plenty of time for it to soak into the wood. It sticks better than any other type of primer to wood. Even though old fashioned oil primer is still the best paint primer for this use, nobody likes to wait 24 hours for a primer to dry before they can topcoat it.  So, the paint manufacturers have developed new, faster-drying technology in both oil and latex-based products. These both dry quickly yet still aid in the proper adhesion of your paint topcoat.

Masonry Paint Primer

There are several reasons why it is a good idea to apply a masonry paint primer before paint. 

  • Some masonry surfaces can have a high pH level which will cause adhesion problems if you apply paint directly to the surface. 
  • A quality masonry paint primer will allow you to safely paint over a wider range of pH levels without risk of adhesion loss. 
  • Another problem is called efflorescence; which are unsightly white, crystalline deposits that can form on any masonry surface. 
  • Many masonry paint primers are efflorescent-resistant and do a great job of keeping it from becoming a problem.

Stain-Blocking Primer 

There are different types of stain-blocking paint primers for specific uses. However, some of the more common situations where their use is necessary are: 

  • keeping water and smoke stains/damage from bleeding through the finish coat
  • painting over top of crayon, marker, or grease; and making a dramatic color change – especially when painting a lighter color over a much darker color.

Bonding Primer

Some surfaces are especially “slick” and pose a unique challenge for even the best primers when trying to get a coating to stick to them.  Some examples would be:

  • ceramic tile
  • glazed block
  • surfaces with a high gloss finish.  

Choosing the correct bonding paint primer for your application assures great adhesion of your finish coat to the surface.

There are a couple of exceptions to these categories:

Multi-Purpose Primers have become very popular because of their universal application for a wide-variety of uses.  However, a word of caution: Some manufacturers tend to oversell these products for situations that they are not necessarily a good fit for. 

Before you grab a multi-purpose primer off of the shelf check the label. Make sure that it specifically states on the label that it can be used for your intended purpose. 

Paint & Primer in One products are one of the newest and most-popular DIY trends in the industry.  What a great idea!  Who wouldn’t want to make their painting project easier by using a product that primes while it paints?  
While this concept is wonderful in theory, it has limited applications when it comes to actually holding up well to the test of time.  Again, a good rule of thumb is to stick to the highest-quality manufacturers if you decide to use one of these products. Additionally, make sure you check the label to ensure it can be used for your intended application. 

Painting Over a Previous Paint Job

A paint project where you’re going over a previously-painted surface does not require the use of a primer.  In many cases all you’ll need to do is spot-prime any bare areas that need to be addressed before applying your finish.

Oil Base or Water Base – How do I Know?

If you’re coating over surfaces that have been painted before, but you’re not sure if it’s oil or water base paint, be sure to use Tru-swipe to make sure you what type of paint your dealing with. Whether you have a base of either oil base paint or water base paint requires the proper category of primer for your project.
If you’re not sure on what paint primer to use, you can always give us a call at Local SD Painting so we can help with your priming
and painting project please contact us for a free consultation and quote! (619) 586-5683