We live in a 1930s house and there has been two cut off lead pipes in the bedroom wardrobe for as long as we have lived here (30 years) They appear to lead up to a metal tank in the loft. (Persumably when cold water was stored) which is all rusted and pitted inside but bone dry.
Problem is, one of these pipes drips water along with some awful white gunge that sets like bird poop on whatever is below it.
I have tried to seal the pipe with silicone but it has breached this and continues to seep out. (see images).
My question is what is the best way to seal these pipes and what could be causing this mess?