Rust on cast iron gate

twopenny

We had a whole 6hrs of dry mild weather today and my very tall gate that's been stored in the garden was dragged out to be sanded of the flaking paint and rust.

It's going well but I can't do it in one go. I've got a lot of rust off to the shiny metal but small bits go deep.

How clean do I need to get it before I can use some red oxide paint? Can I leave a little here and there?

Also is there something I can put on the bits I've cleaned to protect them against the current downpours/snow etc until I get to the end of the sanding and can paint?

It's a 1920's gate that I once took right down to bare metal, used coach paint (neighbour had some) and the top coat is a multipurpose excellent paint for garden metal possibily with a plastic base. With the move it's had 2yrs propped against a back fence on bricks over earth and paint has flaked and rust encroached

Tippytoes

My garden gate was all pitted and starting to rust.  I just gave it a good once over with a wire brush and painted it with Hammerite.  Still looks good three years later.

twopenny

I hadn't thought of Hammerite Tippytoes.

That's a good idea. I used to have to paint it every year or two and it's a bit of a nightmare whichever way you think you have it licked and ordered.

Though it would mean rubbing down 7ft of curliques..........I'll think about that. What else is there to do these days.

Jeepers_Creepers

I wouldn't worry too much about the light surface rust which is reforming on the cleaned bits - this won't develop into anything more than 'surface' over the time you are working on it, and will be easily cleaned off enough to receive a coating of your chosen covering when the time is right.

As to how much of the rest to remove prior to recoating, that's a toughie. Certainly any rust 'bubbles' - where it's clear that the rust is forming under the paintwork and has raised the layer up - that all needs to go. Any completely-adhered paint is fine to leave - it's clearly done its job well up 'til now, and will continue to do so under the new covering. You will, almost certainly, have obvious edges where the paint stops and bare metal continues, so these ridges will remain visible under the new paint - depending on what's used and how thick. You might wish to focus some rough 80-grit paper on these edges to 'feather' them slightly.

And then how to protect and recoat? I don't know the best products to use these days, but I bet there's some really good ones - surely?! Hammerite was a go-to product for such tasks, and I've used it a lot in the past. It has got some good properties (you can apply it thickly, dries quickly, no primer needed etc) but also has some drawbacks (mainly based around its good points...) but is also very fussy about what it's applied to as it has its own unusual solvent base (I dunno - is it cellulose?). You'd at least need to test that it doesn't react with what's already on your gate.

If you decide to go traditional 'red oxide + top coats', then you could always apply thin layers of the 'red' on to the bits you've bared, and every time you clean some more, coat this too - thinly each time - whislt also adding it to the previously oxided parts. This way you should end up with a good few layers of red oxide protection, built up - as it always best - in thin layers. Obviously it would all have to be dry first...

pmartin86

I've had a simular battle a few years back at my mums house, she had a half-height cast iron gate that had seen better days - after spending the best part of a week on and off with wirte brushes, various drill attachments and sandpaper the gate looked fantasic, painted it all up and re hung it, it was amazing for about 3 years or so until it needed some TLC again, second time around (and since then) it got a quick 30 minute sire brush to the worst bits and a couple of coats of hammerite, and she doesn't notice the difference.

Point being, the extra effort you put in to make it "perfect" is rarely noticeable as you don't exactly spend your life starting at a gate, you walk through and and get on with your life - Just give it a quick brush over the worst bits and paint it and move on with life!  

twopenny

Thank you both. It's confirmed what I noticed today while freezing my bits off sanding.

I've used a mouse sander with a 'finger' attachment for the curlycues and apart from the rusty bits which aren't very big,  and getting flaking paint off I worked out that making the edges of the old paint sharp and clean  and any bumpy bits flat it should look smart enough once painted. As you said pmartin, no one will notice once it's done and up because they don't know the agony you went through getting it done.

The weather is helping loosen any bits I've missed making the job a bit easier.

It's just keeping the achieved work clean and tidy while I'm trying to dodge rain and snow. It's too big to do in one go at this time of year. Just hope it fits when I've finished!