Many houses have ornamental ironwork outdoors, usually in the form of railings, gates, balconies, and furniture. Sadly, iron is prone to rust, unless it is well protected with paint or some other surface finish, but some straightforward restoration work can soon put things right.
Cast iron, wrought iron and mild steel are the main metals used for outdoor ornamental ironwork. All these metals have a common enemy, rust, which forms on the metal surface due to the combined action of water, oxygen and carbon dioxide.
Apart from making metalwork look shabby, if left untreated rust can eventually corrode right through the component it has attacked.
Renovating ironwork is a dirty, messy job but the results make a stunning difference to the front of a house, patio or item of furniture.
Preparation
1.) Work on a fine, still day and spread a dust sheet or newspaper underneath and around the work area to contain the mess and prevent paths or floors becoming marked with paint splashes.
2.) Wear old clothes or overalls and protect your hands with heavy-duty fabric gloves. Goggles should be worn at all times when removing rust and when spray painting.
3.) Work away from the house where possible to prevent dust particles and paint fumes drifting indoors.
Removing rust
Rust should be treated as soon as it develops to prevent permanent damage to the metal. Never paint over rust, as it will continue to eat away at the metal under the paint.
The first step is to strip off all the paint, using a proprietary paint stripper. Hot air guns or blowlamps are not very effective for stripping paint from ironwork because the metal conducts heat away from the surface very quickly. With cast iron, the metal may crack under localized heating.
Then, all traces of rust must be scoured away. Rub off light deposits with wet-and-dry abrasive paper or use a proprietary rust remover. With deep, extensive rusting either hire a wire wheel or cup brush on an electric drill, or use a wire brush and plenty of elbow grease.
A proprietary rust inhibitor should then be painted on to the exposed metal. Traditional red lead, calcium plumbate or lead-free zinc phosphate primer can be bought at most car accessory and DIY shops.
For the top coat, use the solvent-based gloss or eggshell paint. Do not use water-based paints as these will give fresh rust a head start.
In most cases paint has to be brushed on. Use a brush that matches the width of the metalwork to be painted. Take care to avoid runs and paint build-up on edges.
Alternatively, use aerosol paint or, for large jobs, hire a spray gun. Spray painting is ideal for items such as garden furniture, but less useful for pieces that cannot be moved, such as railings or balconies.
Treating rust
You will need.
- Dust sheet or newspaper
- Electric drill with wire wheel or cup brush head attachment
- Wire brush
- Chemical paint stripper
- Paint scraper or old knife
- Two clean clothes
- Rust inhibitor
- Paint brushes
- White spirit
- Solvent-based gloss, eggshell or aerosol paint.
- Spray gun
1. Place dust sheet or newspaper under and around items to be treated. Apply the paint stripper carefully following the manufacturer’s instructions. Leave on until the paint bubbles and flakes. Scrape off using a paint scraper or old knife. Clean down the surface according to instructions.
2. Use the electric drill with a wire wheel to remove the rust. Finish awkward crevices with a wire brush. Sweep away any loose bits with a soft brush.
3. Dust the surface with a clean dry cloth. Apply a proprietary rust inhibitor following the manufacturer’s instructions.
4. Degrease the surface thoroughly by wiping with a white spirit. Apply metal primer as soon as the spirit has evaporated. Give edges and corners a generous coat for added protection.
5. When the primer is thoroughly dry, apply the top coat using a spray gun, moving the gun with an even sweep.
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