fix leak in lead pipe water supply

[Johnny B Good]

I finally tracked down the source of water ingress into our basement to a pin prick hole in the lead service pipe just where it enters the building. I've made a temporary repair with a small self tapping screw (unfluted type) and some expoxy resin.

It still leaks but it's now only a matter of millilitres per hour versus the initial 8l/hour I'd ascertained from the water meter readings after shutting the internal stopcock located just 50cms from the entry point in the basement.

I'd like to improve my temporary repair efforts by cutting the pipe at the leak point to insert a 4 or 5 inch 15mm copper pipe, secured with hose clamps. Although it seems like an effective way to make a semi permanent repair, I'm wondering if there'll be any snags I've overlooked, hence my asking in this NG whether I'll be making a serious mistake rather than a cost effective "temporary" repair.

[Andy Burns]

Why not use a proper lead to copper coupler? You'd need to figure out whether it's 5lb, 7lb or 9lb lead, I imagine there's a table of lead pipe diameters out there somewhere?

[Harry Bloomfield Esq]

A hose clamp fitted where the leak is at the moment, might help reduce the flow as a temporary.

A bit of copper pipe and two clamps can work, but the clamps will need to be stainless, because they will rust rapidly away.

[John Rumm]

For a temporary fix on a weeping pinhole, I normally find just tapping the area round the hole with a light hammer is enough to peen over some metal and seal it.

However for a permanent you have two options - a proper coupler, or a proper made up "wiped joint". The former is much easier!

e.g.

Those are the compression style ones - there are also various poly style fittings with rubber O ring seals.

[Clive Arthur]

<snip>

Like this?

[Robin]

the latter a bid more flexible if the pipe is too oval for a Lead Loc?

(I'm too much of a wimp to try to knock it back into shape when it's reinforced by 100+ years of hard water scale.)

[Andrew]

Aren't you allowed one free leak fix per year from your water supplier ?. If so, get them to dig up the road outside and change it all to MDPE through to your internal stopcock.

[SH]

and ISTR that the water companies have a national lead pipe replacement programme?

SFX: tap tap tap for google.....

Aha!

I was right... :-)

S.

[John Rumm]

To be fair I have not tried - if the pipe is deformed I usually just try to find a round bit to make the cut into!

They probably will accept a bit of deformity since lead pipe is not usually that regular.

[Brian Gaff]

Well in this house there was apparently a leak before we moved in half way up a wall in the lead pipe. What it looks like is that a copper pipe is joined using what looks like two rings of something like solder. Its lasted for over 40 years and I'm not about to disturb it to get a loser look!

Brian

[Robin]

none of the links on that page work for me; not too surprising as it's the site of a dormant company

I can't speak for water companies generally but Thames will usually replace their lead pipes (if any) *if* you replace yours. But they won't pay for yours to be replaced. And "yours" includes the supply pipe from the tap in (typically) the pavement.

What you can get for free is a check on how much lead is in your water.

[Jeff Layman]

Would it be possible to freeze the pipe and solder over the leak (before the soldering iron melts the water inside)?

[Johnny B Good]

That's going to cost money on top of my time. :(

I tracked down a list of lead pipe sizes and copied this list posted by a screwfix forum member:-

/QUOTE ===============================================================================

" Old lead pipe is measured by internal diameter the outside diameter governs the weight per yard as follows.

measurements to nearest 1/64"

1/2" Internal dia 5lb =53/64" o/dia ( 21.83mm) 6lb= 7/8" o/dia (22.23mm) 7lb= 59/64 o/dia ( 23.42mm) 9lb =1-1/64" o/dia (25.8mm)

------------------------------------------------------------------------------

3/4" internal dia 6lb= 1-3/64" o/dia (26.59mm) 8lb =1-1/8" o/dia ( 28.58mm) 9lb= 1-5/32" o/dia (29.37mm) 11lb= 1-15/64" o/dia (31.35mm) 12lb= 1-17/64" o/dia (32.15mm) 15lb =1-23/64" o/dia 34.53mm) Philip Dennis, Sep 28, 2015#5

============================================================================== EndQuote/

I measured the circumference to be 73mm using a twist tie and calculated the closest match to be 1/2 inch 7Lb/yd lead pipe.

Using a 15mm copper joining piece means I'll need to swage it out to at least an inch into the cut ends of the pipe.

It's this bit of the job that concerns me a lttle since I no longer have my collection of scrap 1/2 inch 7Lb lead pipe to practice this on. However, if push comes to shove, I do have a length of 1/2 inch aluminium tube I could use as a temporary quick fix whilst I shop for a better coupling option. I'm not so sure that mixing ally with lead is such a good idea but I'd be delighted to be corrected on this point. :)

At least I now know the pipe size with enough confidence, should the need arise, to search for the appropriate sized fittings.

[Bob Eager]

When I had to do this, I used a Johnson coupling (no sniggers about the PM here, please).

I intended it to be permanent, and indeed it was still there when we moved out 13 years later.

[Johnny B Good]

I suspect any such attempt to completely stop the trickle is more likely to undo what I've managed to achieve with a self tapping screw and some epoxy so will pass on that option. However, you raised a good point about the hose clamps.

The ones I bought a couple of months ago (from Lidl since they're a box of Parkside branded hose clamps) don't seem to be stainless steel - no mention of ss on the box label and a magnet sticks very firmly to them.

I might be able to reduce the corrosion hazard by wrapping each clamp separately in SA tape. Alternatively, a thick coating of a bitumastic paint might be a better alternative.

[Johnny B Good]

Thanks for the link (a wiped joint is beyond my capabilities). However I'd need to use a couple of these "1/2" x 7 lb Lead to 15 mm Copper Compression - Lead line" back to back and with the VAT would cost me £16.58 so I'll save that for when my cheap bodge proves to be not such the good idea I think it is. :)

[Johnny B Good]

Not a cat in hell's chance! :) In any case, there's no need to freeze the water when you can simply shut off the supply at pavement stopcock and drain the pipe down so you don't have even a trickle of water boiling away the heat of the blow torch (even a BFO soldering iron stands no chance of soldering a patch onto 1/2 inch 7Lb/yd lead pipe).

[John J]

I've made several "temporary" repairs to pinholes in pipes by using a patch of rubber and a stainless steel jubilee clip. For temporary - one is now 30 years old and the latest is four years old. eBay is a useful source for "samples" of 2mm thick silicon rubber and jubilee clips. The old timers used to drive a small tapered wooden peg into pinholes in lead pipe. The wood expanded when wet and stayed drip free for almost ever. It sometimes created a problem if the pipe was drained for winter frost protection and the wood dried out then it leaked. Holding the peg in place until it swelled again usually worked.

[SteveW]

I think that my big torch might - with the gas pressure turned up to 4 Barg, it outputs 130 kW ! I actually have it for heating copper for silver soldering to make a model boiler.

[Johnny B Good]

Unfortunately, the pinhole leak seems to have been caused by a spade strike (there was only six inches, if that, of soil covering its entry point) so the dent makes such a repair problematical and I'm not certain whether those hose clamps can be opened to permit slipping them over the pipe anyway.

It's why I was planning on cutting at the leak site so I ccould swage it back to round and insert a stub of 15mm copper (or maybe some half inch ally tube) and clamp it with hose clamps. Mind you, I might just chuck £16.58 worth of 15mm copper to half inch 7Lb/yd lead couplers at it.

A question I posed regarding my doubts over the use of aluminium with lead seems to be answered by the galvanic corrosion risk chart and the chemical reactivity chart.

The galvanic corrosion risk is low between lead and aluminium (less than that of copper/lead) but the high reactivity of aluminium with all the halogens (including chlorine) suggests my concern has some justification due to the use of chlorination by public water supply utilities.

If it proves too much of a struggle to insert the 15mm copper into the pipe ends, the ally tube option can at least buy me some time to get hold of those couplers without having to manage without a water supply for more than a day.

Anyway, thanks for offering your suggestions and thanks to everyone who took the time to offer their advice and suggestions. I'll likely have it sorted before the weekend when number one son can spare some more time to assist me. I'll report on the outcome once it's all done and dusted.