Trapped water in pipe while soldering

[millinghill]

Hi. This happened to me last year when it took me 3 separate tries, each time resulting in a leaky soldered joint! The water in the pipe obviously kept turning to steam and making the soldered joint leak. On my last try, it finally took hold solidly. Someone suggested I use bread, as it would temporarily stop the water and then dissolve/be washed out. However, I was soldering the hot water pipes for my heating system and didn't think it was a good idea to have bread floating around in there indefinitely.

I'm now reading a how-to book that mentions a fix for soldering pipes when water's still inside. It says to install a "bleed valve" or "drain fitting" or "vent fitting." I have no idea what these words refer to. Can anyone describe? or refer to an online photo? Thanks! Theodore

[RicodJour]

Google 'bleeder valve' and you'll get the idea.

R

[mm]

I've read that MAPP gas is better than propane in this situtation. Hotter.

I used it for my water heater. Worked fine. Yes, that hot water comes out the faucet.

[Art Todesco]

Of course, a lot depends on the layout of the pipes, but I've used a wet pickup vacuum on one side or the other of where you are soldering. A good place to hook up the vacuum is on a faucet, which is opened to the side, hot or cold, where you are working. I've had success with this method when nothing else seemed to work.

[hrhofmann]

t year when it took me 3 separate tries,

This guy talks about a heating system, not hot water supply, but a small piece of plastic tubing inserted into the pipe and suction applied should be eventually able to suck out the water. May take a while, but the alternative is a good wheat bread that blocks the pipe just long enuf to do the soldering.

[Harry K]

ast year when it took me 3 separate tries,

Yep, some things are just too simple be accepted. Much better to way over engineer the project :)

Harry K

[jamesgangnc]

Yes, stuff bread in the pipe. When you are done, remove the aerater from a downline faucet, turn it on, before you turn the water main back on. Otherwise you will be cleaning bread out of every faucet you have.

[Steve Barker]

OR you might want to google "PEX TUBING"

[Art Todesco]

Also, most hot water systems have some sort of a drain, where suction could be applied.

[Harry K]

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Oddly, the times I have used it (without doing the 'one open faucet' bit), _none_ of those things happened. The bread desolves to the point it passes through the screens.

I wonder how many of you "doom criers" have actually done it.

Harry K

[JIMMIE]

Ive drilled a hole in the pipe before to let out the water/steam then patched it when I was through sweating the pipe fitting. This would probably do the same as the bleeder valve and be a lot cheaper. Heating up a couple of feet of pipe either side the joint to dry it out also helps.

Jimmie

[jw]

Loosen pipe straps. lower pipe till all water comes out, or raise pipes so the water is not near the solder joint. OR Solder in a CU pipe union. Only solder half at a time, then screw it together.

[jamesgangnc]

That doesn't always work. When you're at the bottom of a lot of piping the water keeps showing up for hours. All it takes is a lttle trickle to cause problems. It cools the pipe and it creates pressure when it boils off.

[Harry K]

Or just do the simple thing that plumbers have done for a 100 years. Plug it with bread and be done with it.

Harry K

[DerbyDad03]

I don't know how many fittings you need to install where the water is an issue, but consider a Sharkbite connector.

More expensive, but think about how much time you've already wasted. Available just about anywhere plumbing supplies are sold.

I was sweating a cap on a piece of horizontal pipe that apparently had some water in it. At the exact moment that the solder started to flow the cap shot off the end of the pipe and flew like a bullet across the basement.

The next time I needed to cap a pipe, I used a Sharkbite cap. I had the water off, the pipe cut, the Sharkbite cap installed and the water back on before the commercial was over.

[jw]

So YOU'RE the killer!!!! I read on the news about some guy dying from an airborn copper pipe cap hitting him, puncturing his heart, and killing him instantly. The police are on their way to your home right now. I hope you have a good lawyer.

You dont want to know how I feel about those sharkbite fittings. Not after having one of them come apart inside a wall on a PEX installation and nearly flooding the place. Those things are made for the idiot DIY homeowner who cant use real tools, and for temporary installations of piping during a remodel job.

Personally, I would not use one even for temporary work unless I was watching it the entire day on the job, and shut off the water when I went home for the day.

Hell, at least use a brass compression fitting if you cant solder the thing.....

And as far as caps blowing off during soldering, you're supposed to OPEN at least one faucet in the system before soldering on a cap. The pressure has to go somewhere....

[Tony Miklos]

Go to Lows and buy the stuff that does the same thing. I think it's the same as the corn starch packing peanuts that dissolve in water.