If you have ever tried to spray paint metal, you know that it is a very difficult thing to do. This is because metal is a smooth, non-porous surface, so without proper preparation and skills, your spray paint may end up chipping off.
How to keep spray paint from chipping off metal? Preparing the painted surface, using the right type of paint, and applying thin, even layers are the key to achieving the perfect paint coat for metal.
In this article, let’s learn more about some of the most common reasons why spray paint may chip off metal and what we can do to fix these issues.
Why Sprayed Paint May Chip Off Of Metal
Spray paint is a very beginner-friendly medium because it works on a variety of surfaces, and it can be easily applied without a lot of skills or tools. However, if you find that your spray paint is chipping off a metal surface right after application, here are some of the common reasons why.
Surface Is Not Properly Prepped
When it comes to painting any surface, not just metal, proper preparation is the key to a perfect coat.
That is because any dirt and grease left on the surface can affect how well the paint will adhere to the surface. If your surface is not properly prepared, the paint simply won’t stick, and it will likely chip off right after application.
Metal is also prone to rust, so if there’s rust on the surface of the metal, the paint won’t be able to stick. In that case, rust removal is the required first step to allow the paint to adhere to the surface.
The Paint Does Not Match The Primer
Since metal is a non-porous surface, the paint may not be able to adhere very well to the surface, even if it’s clean. Many experts recommend using a primer on the metal to give the paint a better chance of sticking.
However, there are a few different formulas for paint and primer. If you use a water-based formula for the primer, you should also use water-based paint. On the other hand, if you use an oil-based primer, you should use an oil-based paint.
If you don’t pay attention to what type of paint and primer you are using (even if both the primer and the paint say that they are suitable for metal), the paint may not stick on the primed surface very well. The result: the paint will chip off because it can’t stick to the primer.
The Paint Is Too Thick
One risk of using spray paint is that you may be tempted to paint the entire surface in one go by using a very thick layer of paint on the metal surface.
The problem with that is the layer of paint closest to the metal won’t be allowed to dry properly before another layer of paint is applied on top of it. If the paint is not dry, it won’t be able to stay on the metal.
The Paint Is Not Completely Dry
The temperature and humidity of your working area may also affect how well your paint will dry. If the temperature is too cold, or if the area is too humid, the paint may take longer to dry, and in some instances, it may not even dry completely and may chip off.
Some people enjoy spray painting outside because it helps limit the toxic fumes. This is fine as long as you allow your painted metal surface to dry in a dry and temperate area so that the paint can dry properly before it is put into use.
The Paint Is Damaged By The Elements
If you are painting outdoor furniture or anything that’s to be left outside, the paint will more likely be damaged by the elements. Changes in temperature, humidity, and even dust and grease can damage the paint and peel it off the painted surface.
This is why a protective coat is always recommended if you are spray painting an outdoor piece. The protective layer will protect the paint from the elements and allow the paint to last for longer.
How To Keep Spray Paint From Chipping Off Metal
Now that you know some common reasons why paint may chip off metal let’s explore the best practice for painting metal to achieve the perfect result.
Prepare The Surface
As we’ve mentioned, a dirty, rusted surface won’t be a welcoming place for any type of paint. That’s why before painting, you should always remove any rust, old paint, dirt, and grease from the surface of the metal.
Rust and old paint may require sanding to completely remove. If your metal surface doesn’t have any rust or old paint, then you can use a clean cloth and wipe the surface with some denatured alcohol to remove any dirt or grease on the surface.
You should wear gloves during this step because your hands will likely leave behind oils and prints on a clean metal surface.
Choose A Suitable Primer
Priming the metal surface is an absolutely necessary step when it comes to painting a non-porous surface like metal. A primer will allow your paint to go on smoother, and it will help protect your layer of paint as well.
When choosing a primer (we always choose products from Rust-Oleum’s line when it comes to metal to prevent rust), make sure to match the primer’s formula with your paint’s formula so that the paint will stick to the surface.
Work In A Dry And Cool Area
As we’ve mentioned, working in a dry and cool area will give your paint the ideal environment to dry.
If you are working outside, you should work in the shades where there’s not a lot of wind so that no dirt or debris will be blown your way. After painting, you can move your piece into a dry, clean and cool indoor area to let it dry.
If you are working indoors, make sure to prop open a window or a door. A well-ventilated area will limit the number of toxic fumes that you’ll inhale while you work.
Apply Several Thin Coats Of Paint
When you spray paint, make sure to hold the paint can at least six inches away from the metal surface and move your hands continuously. This technique will create a nice and even layer for the paint.
You can expect to apply two to three coats of paint to achieve full coverage. If so, make sure that the first layer of paint is completely dry before you apply the next layer so that the paint won’t chip off.
Apply A Top Coat
If you are painting an outdoor metal item, make sure to apply a protective top coat to protect your paint from moisture, dirt, temperature changes, and even animals. This step will allow your paint to stay perfect for longer, especially in a harsh outdoor environment.
How To Spray Paint Metal
If you’ve gotten this far into the article only to realize you need a tutorial for the whole process to avoid ruining your metal project, take a look at this tutorial from Ultimate Handyman on YouTube.
Can You Use Acrylic Paint On Metal?