Painting metal can be a tricky business. However, a metal primer will make the job much easier. But how many coats of primer do you need?
You should apply two coats of primer on metal. It is crucial to cover every inch of the metal to promote paint adhesion and prevent corrosion. Apply the primer in short, straight lines to ensure an even application. Wait for 24 hours before applying the second layer.
A metal paint job does not have to be complicated. This article will describe why you should be using primer on metal, how to prep the metal for the application, and how many coats you need. By the end of this article, you will be a pro at metal primer.
What Is the Purpose of Primer?
A primer is a type of liquid coating that can go on a variety of different surfaces. Primer, or sometimes called an undercoat, is the first layer you apply when painting materials.
Using a primer will increase the adhesion quality of the next few layers of paint. Furthermore, primers will increase the paint’s durability and add an extra layer of protection to whatever you are painting.
Why You Have to Put a Primer on Metal
While many people use primers for basic paint projects, some will wonder whether you should use primers on metal or not, and if so, why?
Not all metals need primer, but a lot of them do. The reason is that any moisture in the air will encourage a metal to oxidize. When metal oxidizes, it will start to rust. Oxidation will also weaken the metal, so it is important to prevent corrosion in metal that you use for infrastructure.
Metal primers have elements that will help prevent oxidation, therefore preventing rust from taking over the metal.
Furthermore, metal is probably one of the hardest materials to paint without any sort of primer. When the paint dries, it will come off in flakes since there is nothing for the paint to stick to. Metal primers have binding agents that will help the paint adhere to the flat, smooth surface.
You may also need to use a metal primer if the metal surface you are painting is in poor condition. While there are a few ways to clean rusty metal surfaces, you may not have the opportunity or means to do so. If that is the case, you can use a specific kind of metal primer to convert the rust into metal salts.
How to Properly Use a Metal Primer
Before you know how many primer coats a metal needs, you will need to know what sort of prep the material needs for the primer to apply properly.
Use Mineral Spirits to Remove Grease
The surface needs to be clean before applying the primer. Use mineral spirits, such as the Oil Eater AOD1G35437 Original 1 Gallon Cleaner/Degreaser, to remove grease from the metal. You should also remove any dust and dirt from the metal so the primer will go on smoothly.
If there is any loose rust, take a brush and remove as much as you can. If there is rust you can not get rid of yourself, then use a rust converter primer. Check out the Corroseal Water-Based Rust Converter Metal Primer if you are going with this route.
Choose the Correct Primer
Before you apply the primer, make sure to choose the right one. A few factors to consider will be how you want the metal to look, what kind of environment the metal will be in, and how durable you need the primer to be.
If you are painting a metal like aluminum that prevents paint adhesion, then use a galvanized primer. You can also use zinc chromate primers and iron oxide primers—these will work for just about any metal.
Apply Two Coats of Primer
Normally, two coats of primer will be enough. The most important thing with a metal primer is that you cover every inch of the metal—there needs to be no spot that rust can develop.
- Hold the can about ten inches (25.4 cm) away from the metal and spray in even short strokes.
- Take your time to cover the entire surface.
- Check the instructions to see how long it needs to dry.
- Apply a second coat.
- If the can doesn’t specify, wait for 24 hours before applying another coat.
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You should apply two coats of primer on metal to be safe. Since primer will prevent rust and strengthen the paint’s adhesion, you need to make sure to cover the whole surface area. Take your time applying every coat, and spray about 10 inches (25.4 cm) from the metal. Once you have waited for 24 hours for the first coat to dry, you can go ahead and do the second coat.