Painting Rejas often causes more aggravation and problems than the rest of the house put together. However as with any decorating task if you work safely and securely the less stress-full it is. If you have mobile scaffolding use it; even for the ground floor ones, having the work right in front of you makes a huge difference, and working comfortably makes for a better job.
If you’re working off of a ladder secure it top and bottom, don’t take chances! Whilst doing the prep work protect your hands with gardening gloves, and wear safety glasses. To make life easier still, try and do as much possible from the inside, it’s more comfortable; it’s easier to see where you’ve got to and saves a lot of stretching, and you’ll stay a lot cleaner, As you’re going about the job properly, start by washing everything down, then wire brush off any loose and flaking paint, next, using a scraper chip off any blisters or rust, again wire brushing the effected parts till they have a bright finish, scour the rest with wire wool to provide a good key. Now spot prime any bare metal with “Minio” (we’d call it red oxide primer) followed by good coat of undercoat, finishing with the gloss.
Choosing the right materials I’ve written about choosing materials in a previous article on exterior decorating; I think it’s worth repeating. “Buying better quality paint means you will paint fewer times over the years, and you’ll get better coverage when you do paint. Paint technology has improved dramatically in the past few years, with colours guaranteed to last longer than ever before. You may be tempted to skimp on paint to save money up front with a cheaper brand, but you’re bound to have trouble and eventually pay more in the long run”. That said, I see little point in repainting ironwork using one of the ‘one coat’ hardened finishes available; these are better used on new work; applied directly on to the bare metal. For refinishing work I prefer the traditional ‘prime, undercoat and gloss’ method’. It’s less brittle and less prone to chipping. As you’re “doing the grills” why not use a colour sympathetic to your wall colour. It makes a good job better and such a change from dreary old black!