Can You Spray Paint Epoxy Primer?


spray paint cans

So you have just finished coating your project in a durable epoxy primer and have some time to rest while the primer dries. What’s next? Of course, after priming comes the topcoat, which is usually applied with a brush. But if you’ve had your fill of using a brush, you might wonder if you can simply use a spray can to do the rest of the job.

You can spray paint epoxy primer as spray paints usually contain acrylic or oil paint, both of which can bind with epoxy primer. It is advisable to wait for the primer to fully dry before spraying over it, as certain spray paints can chip off if not anchored properly in a primer.

In this article, you will learn more about spray paints and their relationship to epoxy primers. We will go over the pros and cons of spray painting epoxy primers alongside taking a deeper dive into what epoxy primers are and what advantages they present. Knowing the benefits of epoxy primer can help you decide if using a spray paint over one can offset or eliminate a key advantage of using epoxy primer. So let’s get started with what this primer is.

What is an Epoxy Primer?

Epoxy primer is a sealer that features epoxy. It is not a primer for epoxy resins and surfaces, though the name can mislead one to assume that. Epoxy primers are often used to coat steel and metals in general. It is also used as a final finish in some instances because it is not porous. 

Since epoxy is resilient, if this primer sticks to a surface, the overall integrity of the project is improved. Compared to epoxy resins, the primer layer is thinner and has better adhesion making it compatible with a wider range of surfaces. It can be sanded, painted over, and used as a solo coat, depending on what your project needs.

Benefits of Epoxy Primers

If you’re wondering whether epoxy primers can be spray painted, you already have one of two things: an epoxy primer or a spray paint. In case you have spray paint and may want to directly cover a surface, you should take a moment to internalize the advantages of using the epoxy primer. Remember, the application will be a little complicated and will take longer, but the benefits in this section serve as a reminder as to why epoxy primers are well worth the effort.

Prevent Water Damage

The key benefit of epoxy primers is that they protect a surface from water damage and rusting. When multiple coats of different types are applied over metal, epoxy primer is usually the first base coat because it can keep water from reaching the underlying material. 

Metals prone to rusting often need epoxy primers though galvanizing is a much better solution to prevent rust. Aside from protecting surfaces from water damage, the primer also strengthens the project overall.

Epoxy primers feature epoxy, which (in large quantities) cures to be nearly indestructible. However, a typical epoxy primer application doesn’t contain enough epoxy to make a surface impact-resistant. So, while these primers can theoretically protect surfaces from dents, avoiding scratches is the most they can do practically.

Conducive to most Topcoats

There are many hardening solutions that can lend strength and durability to your project but not each option is as open to being coated. An epoxy primer layer protects the surface underneath while providing a base upon which the topcoat can appropriately anchor. 

Since it is used on typically shiny metals, it is self-evident that the epoxy primer can hold onto smoother surfaces. The top layer isn’t usually that easy to directly anchor into surfaces like shiny metals. It’s not like sanding said metals would be prudent. 

The range of surfaces on which topcoats have a decent hold is quite limited, while epoxy primer can stick to almost everything. Since most topcoats can hold onto cured epoxy primer, the primer expands the usability of such coats.

Excellent over Bottom Coats

Epoxy primers are great at latching onto a surface and drying to maintain hold. As mentioned earlier, this helps them provide an excellent base for topcoats. But aside from being conducive to topcoats, these primers can also be great binding agents for bottom coats. Again, it’s their adhesion that’s to be lauded for this. No matter the type of coat, epoxy primers expand its coverage possibilities.

Concrete Coverage

Just like some paints cannot anchor into a wide range of surfaces, some surfaces aren’t conducive to most types of paint. Concrete is one such material. While one can certainly color over concrete, to appropriately lay a coat over it, one needs to bind a thick layer of paint to the concrete surface. 

Even paints that can cover concrete, direct coverage poses certain risks. Epoxy primer can act as a binding agent between concrete and the top layer, and since different types of paints can be applied to epoxy, the primer increases the coverability of concrete.

Smooth Finish

Finally, epoxy primers can provide an excellent finish as solo coats. In most cases, though, they aid in making a smooth finish possible by acting as the binding agent necessary for a surface that wouldn’t otherwise provide traction to an elusive top coat or a paint that wouldn’t have decent adhesion to a specific surface. 

A smooth finish is desirable in surfaces ranging from walls to furniture, and the fact that epoxy primers can help bring about a nice finish means it will never go to waste. The leftover primer will get used.

Benefits of Spray Painting

Now that you know the benefits of epoxy primer let’s look at the two options for coating it in paint. A paint brush or roller and spray paint. In this section, we will discuss the benefits of spray painting projects in general (with some instances of spray painting over epoxy primer) as compared to using a paintbrush.

Spray Painting is Quicker

The most obvious advantage of spray painting is that it is quicker than using a paintbrush. However, if you do not know what you’re doing, you’re going to spend as much time using a spray can as you would using a paintbrush. 

The real advantage of this relative quickness unlocks when the surface you plan to paint is larger. A small brushstroke requires the same amount of movement as a single spray pump. If the project is the size of an espresso cup, then a few brushes or an equal amount of spray pumps can do the job. 

However, as the area increases to the size of a table, the brush suddenly starts requiring more work. You need to keep returning to the bucket and dipping the paintbrush to refresh its paint supply. The spray can, on the other hand, has a non-stop supply that allows you to continuously coat a surface. That said, if speed is important, then using an epoxy primer might not be a good idea. 

Epoxy primer can dry in thirty minutes on a hot day and can take up to 3 hours to dry on cold and humid days. A fast-drying primer might be better suited for projects that need to be coated quickly. It dries almost instantly. You can start spraying over a quick-dry primer just as you finish applying it, though some waiting time is recommended regardless of how quick-drying a primer is positioned.

Better Reach, Which can Improve Coverage

There is a reason why perfumes and body sprays have atomizers and nozzle pumps instead of nail polish-type brushes. A spray has better reach in areas that one’s hand cannot go. In wearing deodorant, this means one can spray their back, but in DIY painting, this means that cracks and corners get coated in paint. 

Usually, the brush size and your arm length can both dictate how much of a certain project gets covered. If you’re painting a wall, and your arm doesn’t reach the top, then that area remains unpainted unless you get a ladder. But even if you get a ladder, it is possible that the brush is too big to reach the smaller crevasse at a corner. 

This would leave a gap that goes unpainted unless you get a smaller brush. A spray paint creates a jet of spray mist that, at its smallest, is as fine as a single droplet of paint. This means that no matter how small a corner or a crevasse is, the paint can reach it when sprayed.

Novice-friendly

The analogy of body sprays is relevant here once again because not many people have experience using a paintbrush or a brush of any sort. In contrast, almost everyone has used a spray can. That’s why spraypaint is novice-friendly. 

The accessibility of spray paints makes them versatile and useful for beginner to medium-tier projects. That’s not to say that you can be careless when spray painting because messing up a project is possible even when you use spray paint. We’ll expand upon this in the drawbacks section, though.

No Brush Marks

As mentioned earlier, spray paints are novice-friendly. However, using a paintbrush isn’t hard either. It is difficult to use it and have a professional look by the end unless you are a true pro. And the culprit that gives away amateur paint jobs is the brushmark. The residue of the paintbrush’s impact gets imprinted on the surface that’s being painted because of two reasons. 

Firstly, the paint takes some time to dry, and while it is wet, it takes the shape of any impact it receives, including that of the brush fibers. And the second is that it is laid too thick. When you paint too thick, the upper surface doesn’t have as much hold as the lower surface. 

As a result, the brush can dent the topmost area. This problem doesn’t exist with spray paints because you do not physically impact the layer of paint. That said, you have to be cautious of drip marks, which will be discussed in the drawbacks section.

Disadvantages of Spray Painting on Epoxy Primer

If you’re told of the advantages of spray painting only, you will not get the complete picture. In this section, we will go over the disadvantages of spray painting any surface. These apply to spraying over an epoxy primer but aren’t exclusive to that scenario. Even spraying over unprimed surfaces has the following risks.

Uneven Application

The most significant drawback of spray painting epoxy primers is that you’ll have an uneven finish. This has less to do with the primer’s presence and more with the spraying technique. Earlier, we invoked the analogy of a body spray to indicate that spray painting is novice-friendly since everyone has used a body spray at some point. 

The problem is that most people don’t have experience in applying even layers of spray since body spray, room freshener, and other spray bottles don’t function based on even application. You have to be careful when spray painting and must practice on a test surface to avoid ruining the project with an uneven coat.

Harder to Apply on Vertical Surfaces

Another drawback of using spray paint is that when you apply it to an upright surface, you run the risk of paint dripping down, creating a trail that signals amateur work. In most cases, the project can be laid flat and sprayed, but if you’re actually painting a wall, it might be better to use a roller.

Is More Expensive

Finally, the drawback that matters the most: a waste of money. While spray painting is easier and quicker, it costs more money because of two reasons. Firstly, it uses more paint. A lot of the paint is lost in the air and outside the scope of the project. 

Moreover, the actual paint is expensive when you get it in a can instead of a paint bucket. You pay for ten spray containers and get the same amount of paint as you would when paying for one paint bucket.

Final Thoughts

Spraying paint over epoxy primer is practical and possible, but it comes with a few caveats. The speed of spray painting is lost to the primer’s waiting time post-application, and the ease of its use is offset by how expensive it is. But if you’re comfortable with the cost and the technique of spray painting, then there’s no reason you should not spray paint epoxy.

Jedediah Arnold

Jedediah has been working with epoxy resin for a couple of years. When he started, he wanted to share everything he learned as he learned it which continues.

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