How to Paint Metal?

If you’ve ever tried to paint some metal, you might have noticed that regular paint doesn’t stick well to a metal surface, as it does to wood, for instance. Due to its smooth, slick surface, it should be treated differently from timber and plaster. It’s also chemically different, prone to rust and tarnishing. 

Painting metal doesn’t have to be difficult though, just a few simple instructions and the right tools can ensure project success for any metal object. Firstly, focus on the preparation of the surface and secondly, select the paint suitable for metals

What Kind of Paint Do You Use for Metal?

It’s essential to use specialised formulated paint for metal. They come in two forms, oil or water-based. Both have their advantages and disadvantages.

Oil-Based Paints

  • It works well on both indoor and outdoor surfaces.
  • It’s tricky in its application but has more long-lasting results. 
  • Alkyds, pigments and solvents give off a pungent odour.
  • It can fade over time but can be solved easily with a liquid protective coating that can be painted over it.
  • It resists water, stains and dents.
  • It works well on outdoor metals such as a metal fence, metal railing, deckchairs, metal roofing, and barbeque furniture that are exposed to wear and tear. 
  • It works well in indoor areas such as window frames and cabinets.
  • It carries more organic matter, attracting mould, so avoid its use in the bathroom.
  • It can be expensive.

Water-Based Acrylic Paints

  • It doesn’t give off fumes and odours.
  • It resists fading and cracking very well.
  • It is more vulnerable to dents and staining, unlike oil-based varieties.
  • It works well on indoor metal surfaces such as dressers, bed frames or metal furnishings in the bathroom that are constantly exposed to moisture.
  • It dries quicker than oil-based paints and is easier to apply.
  • It tends to be cheaper. 

Whichever type you choose, you still need to do the correction preparation for it; read on to find out how. 

How Do You Get Paint to Stick to Metal?

It doesn’t matter if you’re dealing with iron, steel or aluminium. Painting metal requires some prep work for a lasting paint job. Cleaning with a wire brush or wire brush attachment will eliminate grease, dirt, rust and old paint that can stop paint from sticking properly. 

Additionally, suppose your item of choice is made of galvanised metal. In that case, it’s essential to clean it with a detergent solution or mineral spirits to remove invisible oils. You can either use a wire brush and a damp cloth to get as much grime off as possible or use acetone/rust remover beforehand to aid in loosening it up. 

As a general rule of safety, wearing a dust mask is necessary, as scuffing and sanding can stir up a lot of dust. Using a scuffing pad thatl scratches the surface a little will make the paint primers stick better. 

Finally, get some sandpaper to sand the surface smooth and finish off with washing and wiping the surface well. 

Do I Need to Prime Metal Before Painting?

When painting metal, priming the surface ensures that you don’t end up with a shoddy finish and gives a professional result. 

Remember to have your dust mask on before you begin and preferably a dust sheet. If your metal has surface rust, then apply some zinc chromate primer and immediately apply your metal primer of choice to the area. 

The primer of recommendation is a self-etching primer spray as it’s ideal as a base for paint on metals. If your metal surface has many crevices and small holes, a spray primer would be a wiser choice. If you decide not to go for the spray kind, you can use a regular paint brush or roller to apply the primer.

As a general rule, shake the can for a few minutes and spray in short strokes in a side-to-side motion across the area, holding the can about 8 inches from the surface. 

Let it dry between coats and aim for about two coats in total and check the manufacturers’ recommendations. Remember to let the primer dry thoroughly, about 24 hours, before proceeding to the fun part – painting! 

How Do You Properly Paint Metal? 

Like the primer, painting metal requires the same technique. There are spray paints for metal available on the market in both water or oil-based versions. You can also buy them in regular paint tubs. 

If you choose a spray can, shake it well to mix up the pigments. Move the can swiftly and avoid holding it in one place; otherwise, the finish will not be even. Be careful to keep the can about 8-10 inches away from the metal surface.

You can use regular paint brushes or rollers to apply the paint too. Be careful not to overload your brush with too much paint, as it can create an uneven, lumpy finish on your metal, resulting in a mess. 

You can choose from a wide range of colours, both muted and vibrant. You may like the idea of keeping your item looking shiny by opting for metallic gold paint or silver metallic paint.

Apply your first coat, covering the entire surface area and letting the paint dry thoroughly. This is important as allowing the coat to dry will ensure your finished product has a longer-lasting paint job. Acrylic paint dries quicker than oil-based ones and is generally more forgiving if you make a mistake and redo a section.

For the following coats, stick to about two to three in total and remember to let each coat dry before proceeding to the next. 

Final Thoughts 

It’s important to know how to paint metal properly. It can be an easy process once you have the essential preparation to ensure you have a smooth finish to any metal object in your DIY projects. A fresh coat of colour can make any metal item seem brand new. Just remember the key steps to make sure that your efforts are not wasted. For more information, help and advice, check out Promain‘s Knowledge Hub.