From DIYinfo.org
[edit] First
Make sure all metalwork is clean, free from grease and well prepared before painting.
[edit] Metal Fireplace
Never paint a metal flue while it is hot, always let it cool down first. When you have finished painting, wait at least two days before lighting a fire to let the paint harden.
1. Rub back the existing paint to provide a key for the new paint. Use a heat resistant paint for very hot flues and fire surrounds or the new paint will peel.
2. Put on a second thin coat of gloss when the first coat is dry.
3. Do not paint over the damper or other moveable parts.
4. Coat the inside of open metal fireplaces with a heat resistant paint. Allow to dry then light a fire, the heat cures the paint.
[edit] Pipes
1. Make sure that steel and copper pipes are clean and free from rust or corrosion
2. Apply gloss paint direct with a 25mm or 50mm brush, depending on the size of the pipe.
3. Never paint over stop taps or controls or they will not work.
[edit] Cast Iron Surrounds and Wrought Ironwork
1. Remove any rust. Use a suitably sized brush to coat the surface with gloss or enamel paint direct, without an undercoat.
2. If possible, remove intricate wrought ironwork and take it out side. Then paint it with an aerosol or spray gun, shielding the area behind with dust sheets, paper or cardboard. Always use thin coats to prevent runs. Hold the can or gun at right angles to the ironwork and at a distance of about 800mm. Keep the gun parallel with the surface, moving up and down or from side to side. For an even coat never swing the can or gun in an arc or hold it in one position for any length of time.
3. If you cannot move intricate wrought ironwork, put on two thin coats of gloss with a small paint brush.
[edit] Windows
Metal windows tend to be tighter fitting than wooden ones, so do not let paint layers build up on them. If the paint layers are very thick, remove the paint with a chemical stripper. In all other respects, the painting procedure remains the same as for wooden frames.
