Problematic stains on new plaster

[anthonini]

Hello to everyone, just a bit of advice please. I have rercently stripped the wall paper from my mid terraced ground floor front room lounge in order to have the wall skimmed. On one of the partition walls i noticed that on the wall was a perfectly circular dark spot, about 10 pence size, about 5 feet up the wall. All efforts to rub this spot away have failed.

Anyway, the wall was skimmed and looks good, but when the wall dried, the spot has shown through the new plaster. can't think what this might be, this wall was damp proofed last year. Don't want to paint the wall as i intended as i think this spot will show through, any ideas would be greatly appreciated. Puzzled Anthonini

 

[jbonding]

it sounds like its an old electric conduite either for a light switch or wall light i skimmed over some years ago and their not galvanized so a rust coloured circle shows through, ive been told if you paint gloss over it then emulsion when the gloss dries it wont show through but ive never done it my self.

 

[anthonini]

thanks for your reply. Sounds about right, would be at the right height, and i would agree that the circle is rust coloured. pva'd the walls yesteday, will try the gloss first and let you know, thaks anthony

 

[nod]

If the gloss doesn't work try an alkaline resistant primer paint. Failing that phone the Dulux technical helpline, they have all kinds of cool products.

Nod