Rust-coloured stain

[Steve Bowyer]

Using an angle grinder I've cut off two cast iron brackets which were cemented into a brick wall (they were originally used to support a water tank). I've now filled in the hole flush with the original plaster, but almost immediately, a rust-coloured stain has appeared through the filler, exactly in the position of the brackets. Is this stain going to continue to appear when I paint over the filler with emulsion? Is there any kind of treatment I should put on the filler before I paint the wall?

Thanks.

Steve.

[Rob graham]

Yes!

Is there any kind of

I've used Polycell Stainblock with great success. I think some people have painted the area with gloss paint and it has worked for them

Rob Graham

[Phil Anthropist]

Try gloss or stain hiding paint. If the rust leeches through that you will need to remove the filler back to the rusting metal, cure the rust, then refill.

[The3rd Earl Of Derby]

Dig back out the filler and paint rusty stub with any gloss paint and wait for it to dry,then refill.

This wouldn't be an old bog cistern would it?