I have been asked a few times recently about getting rid of old damp stains.
Due to this i thought i would share a good way of doing this.
If you do have any old damp staining then you should ensure that the issue that caused the damp has been fixed before proceeding with this next step.
Firstly I would give the area affected a light rub down with a fine grade glass/sand paper, wipe surface with a dry cloth or dust off with a soft brush.
Next with a rad roller, roll a coat of oil based undercoat over the stained area, leave to dry overnight.