Before you attempt to paint your wrought iron gate, understand that metallic surfaces like wrought-iron are subject to rust when exposed to moist conditions. You must coat the wrought-iron gate with a special type of primer, formulated to seal existing rust and prevent future outbreaks. In addition, you should apply a topcoat of a particular type of durable paint, or you will ultimately end up with heavy flaking and peeling.
Clean the iron gate, using a pressure washer. Wait two to four hours for the gate to dry.
Eliminate existing rust, using a wire brush and 80-grit sandpaper.
Cover the area beneath the iron gate with heavyduty dust sheets.
Coat the iron gate with red oxide primer, using a mini-roller. Smooth drips and runs using a paintbrush made for oil-based coatings. Wait two hours for the primed gate to dry.
Clean your painting tools with white spirit. Fit a new mini-roller cover to the mini-roller frame.
Coat the primed iron gate with an oil-based enamel, using the mini-roller. Smooth drips and runs, using the clean paintbrush. Wait two hours for the primed gate to dry. Add another coat if the red oxide primer bleeds through.
Do not paint directly over an unprimed iron gate, or the finish will peel.
Do not use an ordinary base primer on a wrought iron gate, or you will eventually end up with rust.