Paint recommendations for cast iron guttering

[CarolineTheChemist]

I'm looking for recommendations for paint for my cast iron gutters. They've clearly not been painted in a long time and I want to take advantage of the scaffolding whilst it's up! I've found this link that recommends Hammercote Smooth Metal Paint. Has any one used it? Are there any others you'd recommend/avoid?

http://www.charlesbudddecorating.co.uk/blog/how-to-repair-cast-iron-guttering

 

[Feltwell]

The preparation is key, ensuring that you've got all the loose stuff off and are back to a stable surface.

For decorating in-situ, yes Hammerite Smooth is fine, I've got gutters painted 10 years ago in that that still look OK now. Not come across Hammercote but it looks like much the same stuff.

There are 2-pack epoxy paints that give the best life of all but I think to get the best from those you need to go back to bare metal and decorate guttering before it is put up - try as you might you will never get perfect all-over coverage painting gutters & downpipes in-situ.

 

[malcolm]

I'm planning to use linseed oil paint on mine. Guessing it is much the same as they did in the past. Works a treat on aluminium guttering without primer but I admit I've not tried cast iron guttering yet. Protecting the outside of cast iron against rust isn't an issue, so the risk will be surface rust showing through the paint. I've had success on mild steel outside with linseed paint over a 95% zinc content galvanising primer which is intended to discourage rust formation. It's nice to avoid plastic coatings that water can get behind.

 

[steveb]

I am surprised by linseed as I thought it effectively worked by soaking into the underlying material, which i would assume wouldn't happen with cast iron - however I would be delighted to be proven wrong. I used linseed on external woodwork and was very pleased (apart from the hard to apply part...)

I guess a proper iron gutter will be a few mm thick which if you did nothing would take a hundred years to rust through so kind of hard to judge effectiveness. In the timescale that people generally care about, do nothing would be equally effective!

 

[Gothichome]

Caroline if you can find this stuff I would highly recommend it. It is used in the automotive restoration so may be available at better auto parts suppliers.
https://www.por15.com/POR-15-Rust-Preventive-Coating
All you need to do is wire brush the loose stuff and apply

 

[malcolm]

Tried some POR 15 on some bumper brackets. It's not UV stable and rust has come through even though I sandblasted first. Did leave a nice finish initially though.

 

[malcolm]

I am surprised by linseed as I thought it effectively worked by soaking into the underlying material, which i would assume wouldn't happen with cast iron

Does take a very long time to dry - needs thin coats and I'm sure it was longer than 24 hours to go touch dry even in mid summer. Not the most convenient option I admit.