Endless drip in cut pipe

[Stereo]

I'm trying to replace a section of vertical pipe that runs from the first to the second floor of our home. The vertical pipes (hot and cold) service two sinks, a toilet, and a bathtub. The cold-water pipe developed a pin-hole leak in the body of the pipe - not at the soldered fittings a few months ago. A plumber replaced a section of the pipe. A different point on the same pipe developed another pin-hole leak yesterday.

I turned the water main off last night, opened the top-most faucets, drained the pipes at basement level, and this morning, cut out as much of the pipe as I could between fittings. However, after more than eight hours, the pipe still has a very slow drip so I can't get the pipe totally dry for soldering. I've heated the pipe to try to evaporate the remaining water but it still drips. I'll deal with the drip with white bread but I'd like to know how/why the pipe is still dripping. Anyone know?

 

[Reach4]

I don't know your access.

How about you remove a long section. Solder on a pipe at the bottom, leaving a particular-sized gap at the top.

While you have the gap, you can make there be no drip for above.

Then fill the gap with a SharkBite Max Slip repair coupling. The Sharkbite will not need a dry connection.

https://www.homedepot.com/p/SharkBi...Brass-Slip-Coupling-Fitting-UR3008A/326882593 is half inch, https://www.supplyhouse.com/SharkBite-UR3016-3-4-x-3-4-SharkBite-Max-Slip-Coupling is 3/4 inch.

 

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[John Gayewski]

Blow it out with air.

 

[Stereo]

Blow it out with air.

I did use a shop vac to blow into three spigots in the bathroom. That speeded up the drip so it might have run our earlier than if I hadn't blown out the line, but I couldn't wait any longer and just used the white-bread trick which worked to get a good solder joint.

I'm wondering if it's possible for the hot water line to somehow leak into the cold-water line through the faucets. thinking that might be possible, I tried to turn off the hot water but the shutoff valve is a gate valve, not a ball valve, so I can't rely on it to totally turn off the water. At any rate, it didn't end the drip.

 

[Stereo]

I don't know your access.

How about you remove a long section. Solder on a pipe at the bottom, leaving a particular-sized gap at the top.

While you have the gap, you can make there be no drip for above.

Then fill the gap with a SharkBite Max Slip repair coupling. The Sharkbite will not need a dry connection.

https://www.homedepot.com/p/SharkBi...Brass-Slip-Coupling-Fitting-UR3008A/326882593 is half inch, https://www.supplyhouse.com/SharkBite-UR3016-3-4-x-3-4-SharkBite-Max-Slip-Coupling is 3/4 inch.

Thanks for the idea, but I don't trust SharkBite behind walls.

 

[Slomoola]

Is your shut off, not shutting off? Sounds exactly like it. Either your main is passing or you need to add another shut off after the main.

Is the main at the street? City water? You need to turn those way past 90 degrees to get them off completely. I thought 90 degrees was enough. I had drip like you said. Researched turning off at the street. Needed more of a turn to shut down completely.

 

[Fitter30]

If there's room could use this tool to stop the water and add a full port valve.

Amazon.com: VAVAQQSE Pipe Water Stopper Kit - Hot-Melt Water Stop Needles for Fast Water Line Pipe Repairs - Stainless Steel Home Improvement/Renovation Plumbing Tool for Professional Plumber : Industrial & Scientific

Amazon.com: VAVAQQSE Pipe Water Stopper Kit - Hot-Melt Water Stop Needles for Fast Water Line Pipe Repairs - Stainless Steel Home Improvement/Renovation Plumbing Tool for Professional Plumber : Industrial & Scientific

www.amazon.com