If you just paint over rusty steel or wrought or cast iron, without adequate preparation, the rust will quickly stain the paint and surroundings, and continue to attack the metal. This will lead to early flaking and then you will have to start all over again. For this reason, good preparation before painting is critical.

Gather your supplies
Wire brush (attachment for a drill or a hand brush); rust converter; oil-based metal primer; exterior self-priming acrylic paint; protective gear

Here’s how
STEP 1 First you should remove any old flaking paint and loose rust with a wire brush. In extreme situations you could use an angle grinder, but in most cases this is not warranted
as you’ll leave grinding marks all over the steel. Use a wire brush by hand or, to make life easier, use a wire brush attachment
you can fit to your cordless drill – they only cost about $8. As paint and rust flakes, as well as the odd wire, may go flying, you should wear eye protection. And wear a mask so you don’t breathe in the dust. This is especially important if the paint is old, as it can contain lead.

STEP 2 Once done, brush away all the loose material and wipe the steel or iron with a rag dampened in water. All you have removed at this stage is the loose surface material – there’s probably some rust left behind. You can treat this with a rust converter such as Dulux Quit Rust, which converts the oxidised steel or iron to an inert phosphate that is stable and can be painted. But don’t use the solution on galvanised surfaces. The Quit Rust will take a few hours to work. Once dry, paint within 24 hours.

STEP 3 When Quit Rust is dry, paint metal with an oil-based metal primer, such as Quit Rust Metal Primer, and let dry overnight. There are a few faster drying products, but you may as well wait until the next day.

STEP 4 Apply 2 light coats of paint. Use a good quality exterior paint, as it has to resist the elements, and painting steel fences is slow and laborious work that you won’t want to
re-do in a hurry. Apply thin coats as they are less likely to peel. Also, when painting wrought iron, work the brush all around the bar. If you just work from 1 side, beads and runs of paint on the back of the section you are working on will dry and be hard to remove. We used Dulux Weathershield Clotted Cream. Devonshire tea anyone?