Soldering wet pipes?

[bluecrush]

Hi thanks for reading my first post. It might be a silly question but looking for a way to solve it.

I resently went on a basic plumbing course in Lemington spa and the tutor who had 37 yrs experience told us that this can't be done (solder a pipe while wet ) even with the smallest amount of water. I found out the other day he was right.

My question is how can you get round it? I looked up and read somewhere about rolling up some bread and putting this in to stop the drips.

Any help would be very much appreciated

Thanks
Craig

 

[Deleted member 2053]

You can solder pipe with a little water in it if you use a MAPP gas blowtorch.

 

[bluecrush]

Hi thanks for that...

Can you tell me why the flux/ solder is prevented from getting drawn in to the joint, obviously some scientific reason?

Wow just looked it up the prices are a little steep £67 + about £19 for the gas. The bread idea sounds cheaper...

Thanks again Craig

 

[Mike Jackson]

Can you tell me why the flux/ solder is prevented from getting drawn in to the joint, obviously some scientific reason?

The flux is already in the joint. The water will continually cool the joint preventing the solder from melting properly and being drawn into the joint. Mapp gas works because it creates a hot enough flame to vapourise the water and heat the surrounding area so that any water boils before it reaches the joint. You've got to be careful or you can overheat the joint and scorch the flux which prevents the solder running properly. It's a pain in the neck to do but sometimes there's not a lot of choice.

Mike

 

[justlead1]

Hi. [DLMURL="http://www.ukplumbersforums.co.uk/members/bluecrush.html"]bluecrush[/DLMURL]
As has been stated water takes the heat away. The bread idea was used when wiping joints (cap and linings). But what with the perfectly protected world we live in i am not sure you can write it on you method statement today. To use this method or any method when water is present you must have an open end, otherwise the pressure due to the heat will blow solder in joint causing a pin hole when tested. The open end may be a tap, valve, doc or say a No. 30 or 29r (tees with one branch screwed to take 1\2" BSP doc or alike. Once you establish the situation described, you ram the bread up stream of the proposed soldered fitting 8 to 12" if possible and then having prepared the joint work fast to assemble and solder. Toast is the first thing you will smell. Once cooled turn on water and wait for the bread to be forced out of the open end. Neadless to say only try this method where yoiu have sufficient pressure to push it out. I have used variation on the theme when replacing back boilers plauged by drips on the 28mm returns, by using rag and wire, once the joint was completed the wire was used to retrive the rag from up the pipe via the 1/2" doc point. Good Luck

 

[stevetheplumber]

generally the best way round is to find a mechanical joint you can break on the downstream side or to introduce one by way of a compresion couplingsome times you have to put a coupling in out of sight to allow you to solder the bits that can be seen

 

[plumberdan]

Bread is the perfect solution works everytime!! Every plumber carries a loaf of warburtons in their van dont they? lol
i once had a job where i used this method.. theres a pinhole in 22mm cold main before the stoptap, turned off the mains outside the property but obviously water was still in pipe, cracked my bait box open out came a slice of warburtons finest rolled abit up pushed into pipe and soldered brilliantly!!

 

[bluecrush]

Many thanks to all those that have written their theory's and experiences.
Some very interesting tips.
Thanks again i'll look forward to trying them out...


In the mean time if I invent something that would truely solve this issue do you think it would sell?

 

[nick penfold]

Also, if ur using the bread technique dont forget to bring some butter and marmite for elevenses mmmmmmm

 

[tonyn]

when soldering pipes with even a little water in you may get steam build up in the pipe you will see fizzing /popping at he joint little bubbles appearing in e solder this will mostly cause a failed joint myself personaly i woud cut pipe resolder joint and use compression fitting on the pipe ive just cut, seems to work for me

 

[jgw1]

Hi there,

you guys are making me nervous now.

I am a diyer who is currently redoing my bathroom. I went on a course to give me the basic skills to do the pipe work and fitting.

I had the old indirect hot water for the basin coming through the floorboard and needed to rework it to where the new sink would be.

I could not work out a way to drain the pipe fully as it was the lowest point in the system, anyway I got a straw and removed as much water as I could.

Then I soldered using Yorkshires.

So there would have been water some 8" below the point I was soldering running perpendicular to the pipe I was soldering onto.

Is this likely to have caused a problem. The cold I did has taken mains pressure and has been fine although it did not have water close by like the hot did. The hot - has not taken any pressure yet?

 

[sonray ltd]

So there would have been water some 8" below the point I was soldering running perpendicular to the pipe I was soldering onto.

Is this likely to have caused a problem.

should be ok.
but their are may factors to take into a good joint. how clean was the pipe etc

 

[jgw1]

Pipe was cleaned with steel wool and the actual joint was nice and dry. Good amount of flux. If anything I cooked the joint though as it went black. It was my first attempt on my own - as a diyer after the course.

Worth ripping out and doing it again?

 

[philtheflush]

i wonder if delia smith has a recipe for that bit of bread once you finished with it, maybe bread pudding for one.1 soldier for your boiled egg youve just cooked in your boiler, who knows

 

[dontknowitall]

The annoying dribble is a pain, usually because a valve or the stop tap won't close properly. A wet vacuum often does the trick for me but you have to be quick or else the water will return before you're soldered.

Also if circumstances allow, you can bend the pipe downwards to drain what's there, then support it upwards as water finds tricky going uphill.

 

[pauls]

thats what i do bend the pipe down to get rid of water or up to keep it back.

ive also been known to siphon it out with a tube

 

[stevetheplumber]

thats what i do bend the pipe down to get rid of water or up to keep it back.

ive also been known to siphon it out with a tube

i often use the manometer tube for this another good tip is putting a plastic sack under pipes inbetween the joists to catch water when cutting

 

[kirkgas]

another way to get rid of the water is to open a tap or disconnect a fitting somewhere else, slip a fitting and cutting of pipe over the cut end you are trying to solder and blow the water out, if there is water passing from a dodgy valve this wont really work but if the water is lying in a low pipe it will work no prob, again it comes back to poor previous installation as we all know any pipework should have a drain valve at the lowest point, remember to blow not suck

 

[Blackcatgas]

The annoying dribble is a pain, usually because a valve or the stop tap won't close properly. A wet vacuum often does the trick for me but you have to be quick or else the water will return before you're soldered.

Also if circumstances allow, you can bend the pipe downwards to drain what's there, then support it upwards as water finds tricky going uphill.

Make sure that the pipe is properly isolated from any new incoming water etc, i like ,dontknowitall use a wet vac, i bung it on the pipe for 15 mins or so while I find somthing else to do it properly sucks out the last few drips, perfect aswell for when youve lifted a board to tee into a pipe and the pipe is full of water.

 

[dontknowitall]

Great for emptying WC, F&E and CWS cisterns and radiators.

And floods - not that I get too many of those ... honest!!

 

[gakmonkey]

A wet vac is your best friend, mapp gas works to a degree but a compression never fails.

 

[kingkenny]

have used a packet of rizlas once to stop a passing valve.

 

[billybongo]

One of the best things i ever bought was a pump that fits on the chuck of your drill , a piece of hose to go over pipe and one to go into a bucket and it empties all the residual water to allow soldering .
They can be purchased at car parts shops for about £7.00

 

[heinz57]

I cut into pipe where possible and use a long screwdriver wrapperd in Bounty kitchen roll, then seal with a comp joint if the cut is too close to
another soldered joint. Sorted!

 

[Blackcatgas]

A wet vac is your best friend, mapp gas works to a degree but a compression never fails.

I wish Id put this. Spot on!