undoing cast iron soil pipe joint

Thsi was discussed in 2004 but I would like to ask for further advice.
I am fitting a new WC to a 1960s vintage soil pipe. The pipe is cast iron and joined with lead which appears to have been cast in place (not foil wrap). I want to remove the last 'extension' piece (about 4" long) which will leave the remaning 'female' pipe at pretty much the exact correct height for my new WC.
The advice in the previous discussion was to dig out the lead bit by bit and to wiggle the pipe by hand working it loose. A 1/4" wood chisel (old) was suggested as a good tool for the job.
My question is: why is it not possible to undo this by putting a blowtorch on the cast iron pipe that is to be removed and to heat it until the lead melts? Is there a danger of explosion? a nager of cracking athe iron of the bit I want to retain?
Has anyone 'dug out' lead from such a joint? Can it really be done in a reasinable length of time? Would a plumber do it that way?
thahnks,
Robert
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And where do you intend the lead to go and set again?
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TMC wrote:

I'd put a metal tin under it to catch it.
RObert
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Robert Laws wrote:

In the past I cut off a cast iron waste pipe where it came out of the wall and used a plastic adaptor you get from the builders merchant. It worked very well and was quick and easy to do. There are several types of adaptor that will accomodate various amounts of missalignment. You can use a special ratcheting cutter that allows you to shear off the socket end off the cast iron pipe. All you do then is apply the special grease supplied to the 'fins' on the adaptor and push it into the waste pipe. You then shove the the bog waste pipe into the adaptor and job done.
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anip

Thinking of doing a similar job - tuits permitting - can you please give details of "special ratcheting cutter ". My soil pipe is secured to the wall by cast iron brackets and there's probably an inch clearance off the pebble-dash.

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Brian Sharrock wrote:

You can rent them from tool hire outlets.
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snipped-for-privacy@fsmail.net wrote:

Worth every penny.
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snipped-for-privacy@fsmail.net wrote:

thank you for this, and for all the other helpful suggestions. This does sound fairly easy to me as I have good clearance around the pipe. using this option I coul deven cit it off before the collar and move the connection position further back, which woulds uit me.
best regards,
Robert
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Robert Laws wrote:

for otehr people who are interested, this is what is being talked about:
http://www.hss.com/g/68230/Soil_Pipe_Cutter__150mm_6_.html
Robert
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wrote:

My son has just done this very thing. He cut the socket off the extension piece with an angle grinder and diamond blade, (scary stuff) then drilled out the lead jointing between the extension pipe and the main socket.
Took about an hour, plus a few broken drill bits!
David.
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I thought people might like to know how I got on. I hired the ratchet pipe cutter that was suggested by Royben. it worked fine. I wrapped the chain (which has cutting disks embedded in it (like those in a glass cutter but bigger) round the pipe and tightened it up, pulled the lever (no too much strength needed) and 'bang' the pipe fractured along the line of cutters. there was a slight smell of burnt metal afterwards.
But then I found that my plastic insert woulf not fit in the inside of the cut pipe - the diameter was too small. I decided to risk something more radical and cut the pipe further back, actually in the branch of the cast "T" piece. This bit is not perfectly circular in section so i thought I might shatter the whole thing. But it worked fine, fracturing with another splendid 'bang'. The plastic insert fits nicely.
I returned the cutting tool to the hire shop within 30 minutes.
So, many thanks for the discussion and for such an easy answer.
Robert
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wrote in > >> > > I am fitting a

I'm grateful that you've reported back ; - Thanks for your description of using the ratchet pipe cutter - I'd downloaded a .pdf brochure off HSS's site but handn't appreciated the 'bang' / shatter effect; thinking it might be a super 'hack-saw' type action: forewarned is forearmed.
Can you please give pointers to the typ of (plastic) insert you used.?

--

Brian



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It was just an ordinary standard plastic loo connector designed for plastic soil pipes. they come with various lengths and angles for doing that final link up to the loo itself. It has those rubber 'flanges' to make a watertight seal. I took the rubber flanges off the 'male' end and the naked pipe fits quite snugly into the cast iron pipe. Eventually I will glue it there with the loo in place and then 'unplug' the loo for tiling etc.
the other thing the HSS leaflet does not convey is just how big the cutter is. It weights 12kg and if the length of the pipe is small you migth not have room for the chain and expander. Ideally ou need about 2" of clear pipe to fit it in. I put an old blanket over it all as I pulled. I was glad I did; had it shattered I think shrapnel would have gone everywhere.
Robert
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Robert Laws wrote:

'In the old days whent I wer a lad' we used to use Oxy Acetlylene torches to do this. A normal blow torch does not have enough heat to melt the lead because the Cast Iron conducts the heat away quicker than the blow torch applies it, i.e.it acts as a heat sink. If it is a horizontal joint the lead just drips out. If it is a vertical joint you have to melt the lead and the 'gaskin' below will burn and the molten lead will drip down inside the pipe.(it never seemed to do any harm).
In your circumstances hiring a pipe cutter, cutting the pipe and using what OP suggests, i.e. plastic adaptor seems the best bet.
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