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Understanding Primers


Welcome to our comprehensive guide on paint primers, specifically tailored for exterior painting projects in the Phoenix area. If you’re planning to give your home a fresh coat of paint, you’ve come to the right place. This blog post will serve as your go-to resource, providing you with all the essential information you need about paint primers.

Why focus on paint primers, you might ask? Well, a primer is a crucial first step in any exterior painting project. It not only helps the paint adhere better to the surface but also enhances the durability and appearance of the paint job. This is especially important in a climate like Phoenix, where the intense sun and heat can take a toll on your home’s exterior.

In this blog, we will delve into the world of paint primers. We’ll start by understanding what paint primers are and why they’re so important. We’ll then explore the different types of primers available—oil-based, shellac-based, and water-based—and discuss their pros and cons.

We’ll also talk about Volatile Organic Compounds (VOCs) in primers, a topic that’s often overlooked but is vital for your health and the environment.

Next, we’ll guide you on how to choose the right primer for your home, considering factors like UV resistance, durability, and VOC levels. We’ll also discuss how to prime different substrates—wood, metal, fiberglass, and masonry—and share some common mistakes to avoid when applying primer.

So, whether you’re a seasoned DIY enthusiast or a homeowner looking to hire professional painters, this blog will equip you with the knowledge you need to ensure your exterior painting project is a success. Let’s dive in!


Understanding Paint Primers

Before we dive into the specifics, let’s start with the basics. What exactly is a paint primer, and why is it so important?

A paint primer is a preparatory coating put on materials before painting. Priming ensures better adhesion of paint to the surface, increases paint durability, and provides additional protection for the material being painted.

Think of primer as a base layer that helps the paint stick to the surface more effectively. Without a primer, paint may peel, crack, or chip, especially when exposed to the elements. This is particularly true for exterior painting projects, where the painted surfaces are subjected to a variety of weather conditions.

In the context of Phoenix, where the climate is predominantly hot and dry, using a primer becomes even more critical. The intense sun can cause the paint to fade quickly, while the heat can lead to cracking or blistering. A good primer can help mitigate these issues, enhancing the longevity of your paint job and keeping your home looking fresh and vibrant for longer.

Types of Primers: Oil-Based, Shellac-Based, and Water-Based

Now that we understand the importance of primers, let’s explore the different types available. The three main types of primers are oil-based, shellac-based, and water-based, each with its own set of advantages and disadvantages.

Oil-Based Primers:

Oil-based primers are a popular choice for many painting projects due to their durability and versatility. Let’s delve deeper into their pros and cons:

Pros of Oil-Based Primers:

High Durability:

Limited Stain Blocking:


Cons of Oil-Based Primers:

Longer Drying Time:

Higher VOC Levels:



Shellac-Based Primers:

Shellac-based primers are renowned for their adhesion and stain-blocking capabilities. They have unique properties that make them suitable for a variety of applications. Let’s explore their pros and cons in more detail:

Pros of Shellac-Based Primers:

High Adhesion:

Stain Blocking:

Fast Drying:

Sealing Properties:

Cons of Shellac-Based Primers:

Strong Odor:

High VOC Levels:



Water-Based Primers:

Water-based primers, also known as latex or acrylic primers, are a popular choice for many painting projects due to their ease of use and environmental friendliness. Let’s delve into their pros and cons:

Pros of Water-Based Primers:

Easy Cleanup:

Low VOC Levels:

Quick Drying:


Cons of Water-Based Primers:

Stain Blocking:

Surface Preparation:

Not Suitable for All Surfaces:



Understanding VOCs in Primers

Volatile Organic Compounds, or VOCs, are chemicals that are released into the air from products like paints and primers. They can have harmful effects on your health and the environment, which is why it’s important to consider the VOC content when choosing a primer.

Short-term exposure to VOCs can cause symptoms like headaches, dizziness, and irritation to the eyes, nose, and throat. Long-term exposure can lead to more serious health problems like damage to the liver, kidneys, and central nervous system. VOCs also contribute to air pollution, as they can react with other gases in the air to form ground-level ozone, a key component of smog.

Many manufacturers now offer low-VOC or zero-VOC primers, which are a healthier and more environmentally friendly choice. These primers are especially worth considering if you’re sensitive to chemicals or have young children or pets at home.

Exterior Painting in the Phoenix Area

Phoenix’s climate poses unique challenges for exterior painting. The city experiences intense sun and heat for much of the year, which can cause paint to fade, crack, or blister. Dust storms, known locally as “haboobs”, can also damage the paint over time.

A high-quality primer can help protect your paint job from these harsh conditions. It provides an extra layer of protection against the sun’s UV rays, helps the paint withstand temperature fluctuations, and makes the paint more resistant to dust and dirt.

Choosing the Right Primer for Phoenix Homes

When choosing a primer for exterior painting in Phoenix, there are several factors to consider. You’ll want a primer that’s highly durable, UV-resistant, and suitable for the type of surface you’re painting. The primer’s VOC content is also an important consideration, for the reasons we discussed earlier.

Oil-based primers are a popular choice for their durability and stain-blocking capabilities, but they have higher VOC levels and a longer drying time. Water-based primers have lower VOC levels and dry quickly, but they may not be as effective at blocking stains. Shellac-based primers offer high adhesion and stain-blocking, but they have a strong odor and high VOC levels.

Ultimately, the best primer for your needs will depend on your specific circumstances, including the type of surface you’re painting, your budget, and your personal preferences.

Priming Different Substrates: Wood, Metal, Fiberglass, and Masonry

Different substrates indeed require different priming approaches. Let’s delve into each one:

  1. Wood: Wood is a porous material and can absorb the primer, so it often requires multiple coats to ensure a smooth, even surface for painting. Before priming, it’s important to ensure the wood is clean, dry, and free from any loose paint or rot. Oil-based primers are often a good choice for wood, as they penetrate the wood fibers and seal the surface effectively. They also help to prevent tannin bleed, a common issue with certain types of wood.
  2. Metal: Metal surfaces need a primer that can prevent rust and provide good adhesion for the paint. This is especially important for iron and steel surfaces, which are prone to rusting. A rust-inhibiting primer can help protect the metal and extend the life of the paint job. It’s also important to properly clean and prepare the metal surface before priming, to remove any rust, dirt, or grease.
  3. Fiberglass: Fiberglass surfaces require a primer that can adhere well to the smooth, non-porous surface. A high-adhesion primer is typically recommended. Before priming, the fiberglass should be thoroughly cleaned to remove any wax or mold release agents, which can interfere with adhesion.
  4. Masonry: Masonry surfaces, such as brick, concrete, and stucco, need a primer that can resist alkali and efflorescence, which are common issues with these materials. Alkali-resistant primers are designed to withstand the high pH levels found in new masonry and concrete. They also help to seal the surface and prevent efflorescence, a white, powdery substance that can form on the surface and cause paint to peel or flake.

Remember, no matter what type of substrate you’re working with, proper surface preparation is key. This includes cleaning the surface, making any necessary repairs, and allowing the surface to dry fully before priming. By taking the time to choose the right primer and prepare the surface properly, you can ensure a successful paint job that lasts.


Common Mistakes to Avoid When Applying Primer

Applying primer may seem straightforward, but there are several common mistakes that homeowners often make. Avoiding these pitfalls can help ensure that your primer does its job effectively, setting the stage for a successful paint job.

  • Skipping Primer: This is perhaps the most common mistake. Many people are tempted to skip the priming step to save time and money, but this can lead to problems down the line, such as peeling or chipping paint.
  • Not Preparing the Surface: Before applying primer, it’s crucial to properly clean and prepare the surface. This means removing any dust, dirt, or loose paint, and repairing any cracks or holes. Failing to do so can prevent the primer from adhering properly.
  • Applying Too Thin a Coat: Primer needs to be applied in a thick enough coat to effectively seal the surface and provide a good base for the paint. Applying too thin a coat can compromise these benefits.
  • Not Allowing Enough Drying Time: Primer needs time to dry fully before you apply the paint. If you paint too soon, the primer may not be able to do its job effectively.
  • Using the Wrong Type of Primer: As we discussed earlier, different substrates require different types of primer. Using the wrong type can lead to problems like poor adhesion or inadequate stain blocking.

By avoiding these common mistakes, you can ensure that your primer serves as an effective foundation for your paint, helping to enhance the longevity and appearance of your paint job.


Choosing and applying the right primer is a crucial first step in any exterior painting project. This is especially true in Phoenix, where the intense sun and heat can take a toll on your home’s exterior. By understanding the different types of primers available, considering factors like VOC content, and avoiding common mistakes, you can help ensure a successful paint job that stands the test of time.

We hope this blog post has provided you with valuable insights into the world of paint primers. Whether you’re a seasoned DIY enthusiast or a homeowner looking to hire professional painters, we believe that armed with this knowledge, you’ll be well-equipped to make informed decisions about your exterior painting project.