Tinman Metalworks Ltd
Answered on 6th Mar 2019 - Member since Mar 2019 - report
Generally, the best protection you can use is Hammerite. It is a paint for metal specifically, to protect it and prevent against rusting. It may be expensive versus other paints, but it is much more effective than other paints I have tried in the past.
Additionally, it is available as a spray instead of a normal paint can, which again, may expensive, but the spray will be much quicker and easier to apply the paint then. (Although, I would recommend using some cardboard handy to hold behind the gates/railings when spraying, to avoid mess.)
You could also add an undercoat of Galvafroid (Anti-Corrosion Paint) which can help avoid corrosion and rust too.
If you want to strip away the existing coats of paint (depending on their condition) you would probably be best to use a wire brush or sandpaper.
Failing any of these options, you could always seek advice from a local metalworker who could assess the condition of your gates/fences. "