How To Paint Galvanized Metal In 7 Easy Steps
Galvanized metal, usually referring to galvanized steel, is a metal that has been coated in a protective zinc layer to help prevent rusting. Hot dipping is the most common method of galvanizing, and the process includes adding a layer of oil to prevent rusting. As such, paint will not adhere to the surface and even when it seems as though paint has stuck to the surface, it will come off and leave a plain galvanized metal surface once again.
However, it is possible to paint this material, by following the steps below. The process requires cleaning and then preparing the surface, ensuring that the zinc coating and the steel are rough enough for the paint to adhere to. Choosing the right paint also helps ensure a successful result from your paint job.
Materials and Tools
How To Paint Galvanized Metal: The Process
1. Clean the Surface
When starting any paint job, it is important to clear the area you intend to paint. Any dirt, dust, debris, grease, oil, or other contaminant can degrade the paint job and may prevent it from adhering to the surface altogether. Use a degreaser to cut through the oil and grease on the galvanized metal and clean the surface in small sections so you can keep track of what is clean and what is not.
2. Scour the Metal
Once cleaned, scour the surface using an abrasive, high-grit sandpaper. This will remove any white dust and any remaining oil from the surface and prepare it for the vinegar that you’re going to add in a minute.
3. Wipe With Vinegar And Leave To Dry
Use mineral spirits, or vinegar, and wipe over the whole surface of the metal that you intend to paint. The acidic vinegar will etch the surface, which means that it will be rougher. It will give the paint something to adhere to. Ensure you evenly cover the whole surface, or you could end up with an unevenly painted surface at the end. Once finished, leave the vinegar to dry for about two hours.
4. Apply Primer and Leave To Dry
Primer will even out the porosity of the surface, helping ensure a smooth paint job while also allowing the material to take on paint. Evenly apply a layer over the galvanized metal. Use an exterior latex primer because this will give the best adherence on this type of surface and for the paint you will be using. Let the primer dry. You can leave it overnight or follow instructions on the primer tin but do ensure it is fully dried before moving on.
5. Apply First Coat Of Paint And Dry
Similarly, you will want to use an exterior latex paint. Use a brush and apply an even single coat of paint to the metal. Use long strokes and dab into difficult to reach spots. Allow it to dry for three or four hours and until dry to the touch.
6. Add A Second Coat
Once dry, apply a second coat in the same way you did the first. Apply the paint evenly, ensure you hit any spots you missed first time around.
7. Leave It To Dry
Once you’ve applied the final coat, all you have to do is wait until the paint is dry. If you can leave it overnight, that will give more than enough time. Otherwise, it will take between four and six hours to dry completely.
What Kind Of Paint Do You Use On Galvanized Steel?
If you have cleaned and primed the surface properly, galvanized metal can be painted with an acrylic paint but a latex paint that is designed for exterior use will give the best possible results.
Do I Need To Prime Galvanized Metal Before Painting?
Galvanized metal is notoriously difficult to paint, although if you clean it and prepare it properly, and use the right paint, the job shouldn’t be too difficult. It does require priming before painting, however, to ensure that the paint can adhere to the surface and remain there.
Can You Paint Straight Onto Galvanized Steel?
The same properties that help reduce corrosion on galvanized metal also reject paint when it is applied. This means that it is virtually impossible to paint directly on the surface. Even if the paint seems to be taking when you apply it, once it starts to dry it is likely to simply slide off or fade away. You need to clean, remove oil, and then prime the surface before painting, to overcome these properties.
Galvanized steel is difficult to successfully paint if you don’t prepare it first, and even when you think you’ve been successful, you will return to find paint-free metal. Using some degreaser and vinegar, as well as sandpaper and a little bit of effort, you can prepare the metal so that it is ready to accept your paint job, however.
See Also: How to Paint a Metal Front Door
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