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De-soldering main water line

4K views 15 replies 6 participants last post by  MikeKy55 
#1 ·
Okay, I have my main copper supply line coming thru the foundation about 4 feet up from the basement floor. It sticks out from the wall about 4 inches, has a 90º to your right, short pipe, 90º straight up and supplies the house.
I propose to sweat the 90º off the main line, shorten the line by 1.5 inches and resolder. Knowing that the pipe is going to be full of water, I figured I would cut the 90 with a hacksaw so as to get the water out of the line, de-solder the 90 and replace it. Since the gator bites are so easy to use, that is very tempting. But, this being the main supply line and having the potential to fill my 1200 square foot basement to ground level if it happened while I was away, what do you guys suggest?
I don't mind telling you I'm a little nervous about soldering the main line, but it has to be done.
 
#5 · (Edited)
Why not shut the water off at the main and open an outside tap to drain the line (assuming the tab is lower than the pipe being cut. Then cut the pipe with tubing cutters to avoid possibly jarring other joints loose wrestling with a hacksaw? If you decide to do any soldering on the pipe, stuff the end of the pipe with bread if the main does shut completely off, open the closest tap downstream to relieve pressure from the heat buildup inside the pipe and do your soldering. Soldering on a closed system can nasty if it blows up in your face. That's why I mention open the nearest tap/faucet. When you turn the water back on at the main, the bread should wash through and out.

That being said, compression fittings may be the way to go if allowed. Unless they are covered, I assumed they would be allowed.

The tube cutter might give you a better more squared cut for your pipe. This important if you have to doing any flaring. I realize the location of the pipe may not allow you to use tubing cutters, just thought I toss the suggestion out there.
 
#6 · (Edited)
I just reread the op trying to get a picture in my head. Sounds like you are talking about soldering two joints close together. This can be tricky for the inexperinced. Be very careful of fire and melting solder off of one joint while soldering another.

Now the picture in my head is showing the outside tap being higher than the supply line. I would think you could still drain the pipe and pack it with bread if need be.

Now I wonder how the pipe entering the basement wall is going to line up with the one going up into the house. I guess the one going up will have enough flex to allow turning the last el enough for a good fit.
 
#7 · (Edited)
Maybe these photos will help. I just need to shorten the incoming line by about an inch and reconnect. Looks like it will work okay, as long as the main shut off at the street seals off good. The main shut off for the house is about a foot above the joint in question, so that should hold back water from the house. Hopefully.

The hack sawing I was going to do was just to open the 90 enough for water to leak down. Cut it right in the bend. A slot or so.
 
#8 · (Edited)
MikeKy55,

From your photos, you have a gate valve on your main line. Why not take this opportunity to replace that gate valve with a new quarter turn ball valve? You can shorten the line and replace the valve all in one shot.

The second advantage of shortening the line by replacing the gate valve is that you will have about a foot of vertical pipe before the valve. This can allow you to solder even if the main line valve outside of your home has a slow leak. Also, consider installing union couplings above and below the valve to make it easier to replace the valve years down the road without any soldering.

Using union couplings can make it VERY easy to solder if the main valve outside of your home is leaking. The way I do it is, I attach a length of 3/8" copper pipe to a shop vac using a cut off piece of garden hose and duct tape. I install one side of the union coupler on the main line pipe and shove the 3/8" copper pipe down into the main line pipe. Turn on the shop vac and I have all the time in the world to solder the union coupler to the main line pipe no matter how fast the leak may be. Also, using a ball valve with threaded connections allows installation without heat from soldering affecting the ball valve.

EDIT: I see now that I misunderstood your intent. But you can still replace the gate valve with a quarter turn ball valve. Just have the lever facing a stud and be able to rotate outward to close the valve. This would allow you to build an access panel with a door to cover the valve.

HRG
 
#10 ·
Looks like you are finishing the basement with new wall going up. Make sure you leave an access panel for that valve and I would move that ground bonding clamp up next to the valve so that it accessible.
 
#11 · (Edited)
so that should hold back water from the house. Hopefully.
Not during the repair, right? I would leave that valve open and the faucet above it open to relief the pressure from the heating of the tubing. In fact, I might would remove any washers in it, at least wrap a moist rag around it or between it and the joint in question as a heat sink.

I was also wondering why you want to shorten the tubing.

I had the same thought about the grnd wire and an access panel. The panel might be the best idea and leave the tubing as it is.


P.S. Allowing the pressure to escape not only prevents the line from possibly blowing up in your face, but it also avoids the new solder from blown back out defeating the capillary action the draws the solder in the joint.
 
#12 ·
WOW! a bunch of great suggestions, kudos. I do plan an access panel. I was thinking of a small HVAC return grill or perhaps a small speaker grill. Painted the same color as the wall, you wouldn't notice it. I'm heading to the HD and maybe Lowes shortly and will look thru all the valves and see what I can come up with. If the original plumber had turned that valve 90º, I wouldn't be doing this. That would be the best thing in my mind now. Oh and thank you for suggesting moving the ground clamp. I will do that for sure.
 
#15 · (Edited)
If you use union couplers, be sure to connect the ground clamp on the input side of the coupler to insure a solid ground path. If you use ground clamps to the copper pipe elsewhere in your home, jumper the union couplers with clamps and ground wire (probably jumper regardless). Or don't use union couplers and use the type of ball valve that is soldered in.

HRG
 
#14 ·
Thats trick. It also saves me another spot where I need access. We have a gas fireplace above another area in the basement with the gas shut off being in the ceiling of the basement. Thank you very much.
 
#16 · (Edited)
Well, I took the path of least resistance. This just seemed like the thing to do. Plus it's easily accessible if it ever fails (save what ever damage that might occur). I moved the ground clamp up farther on the line, but wasn't sure of the conductivity of the shark bite fittings, so I stopped just before they came into play.

Thanks everyone for their advice.:thumbup:
 
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