How can I solder a pipe that has a bit of water in it?

[Stubby]

I'm trying to insert a 6" section of 3/4" copper tubing in a heating pipe that runs through a channel in my house slab. I have the zone disabled, the water into the boiler turned off, the drain valve on that zone open and a spigot used to release air and facilitate draining open.

But there is a constant drop of water in one side of the pipe that I intend to solder. I know I can't solder a wet pipe. I'm reluctant to try the old bread trick. Is there any kind of "solder", maybe epoxy that will work with the wet pipe?

Suppose I fail in the repair attempt (this is the third time!). Is there some sort of clamp that will seal off the leaking joint?

TIA.

[RicodJour]

You could try one of the new compression fittings that don't require soldering.

sold at the big box stores.

R

[ds549]

wad up some bread til doey ,stuff it in the pipe and solder

[Clark]

[e-mail] wrote in news: [e-mail]:

Why does a wad of bread in a boiler not sound like a good idea?

[professorpaul]

I'd go for the compression fittings. I had a similar problem with an old house and rather fragile Cu. water pipes, that I didn't want to take a torch to, and could not be drained. However, I used the conventional compression fittings that you put on with a PAIR of wrenches. Cleaned stuff down good first, and lubricated everything lightly with silicon grease. Sold the house a couple of years ago, and as far as I know, the fix worked.

There are some water soluble plugs -- have seen them, but not used them -- which can be inserted to keep water out. They then dissolve in a couple of hours. Look like big vitamin pills/gel caps.

[mm]

Are you then going to turn something on so that it is under presssure again??? Or will it from now on have no more than a drip which can also drain through the other end of the pipe?

I don't know what is wrong with the bread trick, and I can't tell if your pipe is very close to the slab or not, but to answer your specific question, PC-70 will go on to a wet, even a dripping sink drain and cure and patch the leak. But the drain had next to zero water pressure, even when the faucet was on. BEcause it was on the side of the pipe, maybe wrapped around it, the mixture kept falling off slowly, and I would have to push it back up until it hardened enough not to fall. I think it sets in 15 minutes. Great stuff with lots of uses. Lasts for years and years if one doesn't let any of A touch B. The pair of four ounce cans is a lot cheaper per ounce, but the small size (one two-ended cardboard tube) is sold at HD.

[Toller]

I have used epoxy, but it specifies the pipe has to be dry. I have also bought, at a store going out of business, a CA glue that says that a small amount of water does not matter. I can't verify it actually works, as I haven't used it yet. But that is exactly what I bought it for.

[Doug Miller]

"copper tubing in a heating system" implies that it will again be pressurized, typically to around 20 psig, once the repair is completed -- and may be carrying some *very* hot water.

You don't want breadcrumbs circulating around inside a heating system. They're not good for the valves.

But does it work (a) under pressure, or (b) at higher temperatures than are normally encountered in domestic hot water use? Residential hydronic heating systems typically operate at pressures around 20 psig and temperatures of 160 to 185 degrees F.

[Oren]

My limited understanding of using the "bread trick" is that is needs to be flushed out through a faucet(s) with the aerator removed to clear the line. Can one do this on a boiler?

-- Oren

"I don't have anything against work. I just figure, why deprive somebody who really loves it."

[DanG]

If you are afraid of the bread method . . . .

Often you can cut apart more of the pipe. You don't tell what is causing the drip, but cut out enough pipe to get beyond it. Solder up all the low joints and save a high joint for the final solder work.

[Oren]

Thanks. I see this works with Pex ... good to know.

-- Oren

"I don't have anything against work. I just figure, why deprive somebody who really loves it."

[Art Todesco]

[Doug Miller]

That's pretty clever -- I'll remember that one. Thanks. I like that.

Probably won't work for Stubby, though. He's working on a hydronic heating system, not a domestic water supply, and probably doesn't have any faucets available to him:

[Robert Allison]

They're sold at the big box stores.

Rico,

Since when have compression fittings been "new". I have been using them for about 30 years, albeit that was on industrial jobs as a tubing fitter. What is new about these?

[Oren]

Not to speak for Rico, but this fitting would be "new" to me. It works on Pex; apparently, and I am a first time owner of Pex plumbing.

-- Oren

"I don't have anything against work. I just figure, why deprive somebody who really loves it."

[Mike Dobony]

They're sold at the big box stores.

With a boiler heater I would recommend a flare fitting over compression. It is a bit more work and you need to get a flare tool, but it would be a better solution given the application.

[marson]

You're assuming the OP has soft copper?

[Meat Plow]

Why wouldn't it be? Pressure?

[marson]

He didn't say one way or the other. Better find out before you start trying to sell him on flare fittings.

[Meat Plow]

Well I wasn't trying to sell the OP on anything because you're right in there was too little info.