How to Paint a Metal Gate and Treat the Rust

To paint a metal gate, you need to remove the loose rust, sand, clean, apply an anti-corrosion primer and finish with exterior enamel. If you paint over rust, it will come back through the paint. Preparation is the most important part.

Materials needed

A wire brush or rotary brush and sandpaper for metal.
A scraper.
A suitable thinner or degreaser, and clean cloths.
Anti-corrosion primer for metal.
Exterior enamel made for metal.
A brush and a mini roller.
Gloves, safety glasses and a mask, to protect against dust and fumes.

Step 1: remove the rust

Start by scraping and brushing the areas with loose rust and lifting paint. Carry on until you reach clean metal or a firm area. Then sand the whole surface until it is dull, because new paint bonds better to a slightly rough surface.

If the rust is very deep and the metal is pitted through or weak, painting will not solve it. In that case, the gate needs repair by a metalworker.

Step 2: clean

Remove all the dust with a clean cloth. Then clean with a degreaser to remove grease from hinges, hands and dirt. Let it dry completely. The metal has to be clean and dry for the paint to adhere.

Step 3: primer

Apply the anti-corrosion primer, paying attention to the corners, welds, screws and the underside of the gate, where water collects. Wait for the drying time stated on the label. If any spots of rust are still showing, treat them before going on.

Step 4: enamel

Stir the enamel well before use.
Paint the corners and details with the brush.
Use the mini roller on flat areas for a more even finish.
Apply two thin coats, leaving the interval the manufacturer states.
Let it dry well before closing and opening the gate, so that it does not stick or get marked.

Common mistakes

Painting when the metal is damp or in the rain.
Applying a single thick coat, which runs and dries badly.
Not protecting the hinges, locks and automatic mechanisms. Cover them with tape and plastic.
Using wall paint instead of metal enamel.

Automatic gates and coastal areas

If the gate has a motor or sensors, switch off the power and cover the components well before painting. Near the sea, rust comes back faster. In these cases, wash the gate with fresh water regularly and touch up the first spots of rust straight away.

A small flaw in the paint is the way in for moisture. The sooner you touch it up, the longer the paintwork lasts.

Tip: Paint on a dry, windless day. If the gate is in direct sun, start with the shaded areas or wait until the end of the day, so the paint does not dry too fast.