"Alasdair" wrote in message
m...
Folks,

I wish to separate two sections of a cast iron soil pipe, which appear
to have been socket joined using (lead?) solder, covered by bitchemen
(which I have chipped away).

Is there any technique to break this at the joint, or is my only
option to cut the iron pipe and then fix a plastic pipe to the stub?

I don't want to just try to melt the solder with a blow-torch due to:
1) fear of soil gas explosion - is this founded?
2) fear of setting light to the 40 year old dust on the other side of
the partition wall 1 cm behind the joint.


I've tried to illustrate below. What I want to do is remove pipe B,
and replace it with a plastic pipe, as this will give me more
flexibility as I need to move the WC. In fact pipe A and B are
slightly angled, but I couldn't show that with my ASCII art!.


(I'm in London W5 if it will require a professional job and anyone can
recommend a good plumber)



+ -thin partition wall
+
: c : +
: o : +
: m : +
: u : +
: n : +
: u : +
: a : +
: l : + **** ====
: :********* ===========
: s pipe A pipe B - WC connects here
: o :********* ===========
: i : + **** ====
: l : +
: : +
+
+



Thanks,


Alasdair

Two techniques were used for cast iron socket joints:

a/ pack with a hemp grommet (to make solder proof and central, pour lead in
using a clay mould or direct if vertical

b/ pack with lead foil and hammer home.

With the b/ technique it can be unpicked with care, stating by screwing in a
wood screw and pulling on it, but this doesn't work with the a/ method.
With GREAT care it can be cut out using a very narrow wood chisel but it is
very difficult to get right down to the bottom of the joint and remove
material (particlarly if you are up a ladder !!!). If the joint can be laid
down the lead can be melted out but be sure to gently warm the c.i. or you
will crack it

Andrew Mawson