[dumplings]

Has anyone experience of painting the metal frame of a greenhouse, i was thinking of using Hammerite metal paint?

[arugula]

You can use Hammerite, it works on ferrous and non-ferrous metals, so it will work on aluminium.

Unless its Crittall? Crittall would take metal paint any way, as long as your surface was cleaned back down to metal.

Not sure why you would want to paint your metal greenhouse unless its a particular colour...

[Kleftiwallah]

If it's an ally greenhouse, after a while a coating builds up on ally and then excludes the air from any futher corrosion.  Why paint?

Cheers,    Tony.

[fatcat1955]

Thought the old hammerite was now banned.

[arugula]

Thought the old hammerite was now banned.

They still make it, but it isn't the same.

[JayG]

I remember a school experiment where we removed the natural protective oxide layer from sheet aluminium using mercury, and then stood back and watched a white furry deposit eat through the metal before our very eyes (bet they don't do that one in schools these days!) 

Found this article about painting aluminium, which seems to present so many possible preparation problems whether bare or previously coated you might be glad if yours is in fact a Crittall!

As for Hammerite, it used to claim you could paint straight over firm rust and everything would be protected and look lovely almost for ever!  :happy: Although it was a very good product it wasn't that good in my experience, and I've no idea whether the new formulation is better or worse.

[arugula]

As for Hammerite, it used to claim you could paint straight over firm rust and everything would be protected and look lovely almost for ever!  :happy: Although it was a very good product it wasn't that good in my experience, and I've no idea whether the new formulation is better or worse.

As I said (from experience - both selling and using), the product isn't as good as it used to be, but it is still formulated for use on bare metal.

[dumplings]

thank you everyone, it is an old greenhouse and the metal is discoloured, needs a good clean and then I will see what it is like, I like the dark green greenhouses, but i was going to try and paint the old one first.

[arugula]

thank you everyone, it is an old greenhouse and the metal is discoloured, needs a good clean and then I will see what it is like, I like the dark green greenhouses, but i was going to try and paint the old one first.

You're in luck then, hammerite do a dark green:

http://www.hammerite.co.uk/products/direct_to_rust_metal_paint_hammered_finish.jsp

[Bigbadfrankie]

We painted ours you have to use the primer for alloy .It was a pain to do with all the fiddly bits to paint