Painting cast iron downpipes - how to prepare?

[littlebeside]

Hi, I have to paint some cast iron guttering and downpipes - they haven't been done for a long time - there is alot of flaky paint. What is the best way to prepare? Should I remove the whole lot with paintstripper and scraper or wire brush - I am sure that is going to be like scratching nails down a chalkboard   Or can I just remove the flaky bits with sandpaper? I have no experience with cast iron - any tips gratefully received! Tks. LB

 

[confidentincompetent]

If badly rusted remember you will never stop the rust coming back not matter how much time and materials you put into it. So I would not strip off.
Basic: Clean out gutters with wire brush, scrape any loose off, dust out then prime any bare metal with a good quality rust inhibiting primer (rustoleum combi primer will hold rust staining back for at least a yr ) Then I use up any old oil based paints (sludge paint) which I have left over from other jobs. (recycling the traditional way ) Ok thats the inside of gutters..lol Outside and pipework. I Use various scrapers and abrasives 80/100 g ally oxide basicly to get the loose off and all that scale twixt back of gutter and facia boards. (a piece of abrasive wrapped round a scraper is good for this). Then generally clean/ dust off. prime any bare metal then undercoat and gloss. If you want to impress give it two coats of gloss this should last at least 7 yrs. This kind of job I do wear me goggles, hat and a pair of gloves.
Some will say use hammerite. I have been verrrrry dissapointed with hammerite.. I just use a qualty trade gloss/u/c Dulux, johnstones, crown etc. I wouldnt shell out on weathershield for metal's as weathershield is meant to combat movement in wood.
Phew good luck..

 

[littlebeside]

So I would not strip off.
Basic: Clean out gutters with wire brush, scrape any loose off, dust out then prime any bare metal with a good quality rust inhibiting primer (rustoleum combi primer will hold rust staining back for at least a yr ) Then I use up any old oil based paints (sludge paint) which I have left over from other jobs. (recycling the traditional way ) Ok thats the inside of gutters..lol Outside and pipework. I Use various scrapers and abrasives 80/100 g ally oxide basicly to get the loose off and all that scale twixt back of gutter and facia boards. (a piece of abrasive wrapped round a scraper is good for this). Then generally clean/ dust off. prime any bare metal then undercoat and gloss. If you want to impress give it two coats of gloss this should last at least 7 yrs. .

Confidentincompetent - thank you so much! Especially the part - I would not strip off - I thought I hadn't spotted anyone else doing that! I don't feel it is such a daunting task now - thought I am sure I will when I am up there LB