Trouble getting a copper pipe sweat fitting sealed

[NateDN10]

Long story short, the shutoff valve on the output of my water heater wouldn't open back up after I closed it. I have copper pipes so naturally it's all sweat fittings. After dickering for awhile I decided to try to replace it myself (haven't worked with sweat fittings before). So I cut the pipe above and below the existing valve and replaced with a new ball valve joined with lengths of pipe and couplings. The sweat fitting closest to the water heater is weeping and after retrying 4 times I think I might have to start over. I'm thinking I may not have sanded the existing pipe well enough or something.

So now, going from the top of the water heater on up, here's what we have now:
preexisting pipe -> coupling -> new pipe -> new valve -> new pipe -> coupling -> existing pipe.

If I cut off the problem coupling I'll have to use 2 couplings plus a short section of new pipe and it'll wind up as:
preexisting pipe -> coupling -> new pipe -> coupling -> new pipe -> new valve -> new pipe -> coupling -> existing pipe.

Is that the right thing to do? Any suggestions for getting this last connection to seal?

 

[tomcat27]

clean the pipe and fitting with a green scrubby; use flux, heat the fitting and the pipe (focus on the heavier piece) feed the solder into the joint from the side opposite your flame - it should melt and wick into the joint. oh, make sure water is not interfering

 

[Oldtom]

Some things to try

All fittings must be polished as bright as a new copper penny. Nothing else will work.

Use temperature indicating solder flux. The color change will tell you when to apply the solder. Home cheepo and Lowes sell this.

Remember solder always flows to the hottest part of the joint. Heat the joint as evenly as possible to avoid cold spots.

>>>> OR

 

[BigCahuna]

You won't be able to sweat the joint if the valve is leaking. You only have to rough up the copper, and apply flux to prep it. Heat the copper fitting for a minute or more on the bottom or side . Remove the torch, and Touch the solder on the top of your joint a few times until it melts and fills the seam all around. Now if you have a valve that won't seat and shut the water completely off, an old plumbers trick is to stuff the pipe with bread until it stops up the leak.Then quickly assemble the coupling or elbow, and sweat it as I described. The water will desolve the bread and it will flush out. Let the joint cool for a minute or more before you put pressure on it. Good luck.,,

 

[spasm3]

Make sure there is no water in the pipe near where you are using solder. Use flux as mentioned above. If its clean, and you are using the correct flux and solder it should work. Make sure you don't move the joint while you are applying solder, and no movement after until it cools.

 

[Chris142]

Most people try to solder with it still too dirty

 

[jhellwig]

Even if there isn't water in it if it is pooled next to it will boil and force steam out making it to cool to shoulder no mater how much you heat it.

 

[wog]

Shark bite+1 or ? Get plumber. When you heat pipe and solder hit joint with flux brush to move solder around and in to any gaps. If h20 is present it will bubble solder out of joint use flux brush to move solder around .if not cleaned well the joint has to be taken apart and shined.male and female. Maybe shark will get you out of situation. Good luck

 

[Leo99]

I learned this the hard way. If it's spitting, you have water in the lines. I've used sharkbites a couple times to fix a water pipe leaking out a pin hole in my ceiling. They work great.

 

[NateDN10]

Thanks, all. I'm pretty sure it was dry, but it may not have been clean enough, since that was one of two unions to existing pipe. I think I'm going to try the SharkBite in the morning... Gotta get it fixed or we're not taking showers!

 

[JTK]

I've been down this road before and it was always because I couldn't get that section of copper completely dry. I've even melted the seats right out of ball valves trying to get it done.

I do love sharkbites or the equiv.

 

[JBinKC]

My suggestion if you had a dry clean rough surface is to use mapp gas and tinning flux.

 

[abycat]

Originally Posted By: Oldtom
Some things to try

All fittings must be polished as bright as a new copper penny. Nothing else will work.

Use temperature indicating solder flux. The color change will tell you when to apply the solder. Home cheepo and Lowes sell this.

Remember solder always flows to the hottest part of the joint. Heat the joint as evenly as possible to avoid cold spots.

>>>> OR div>



good advice. Or 3rd option a compression fitting.

 

[NateDN10]

The SharkBite coupling worked great. This is the one I used.

With the solder I made 6 unions and the other 5 seem to be solid. Hot water is back on now and no leaks.

Thanks again for the help!

 

[Oldtom]

Sharkbites are expensive but can be a livesaver. I had to fix a plumbing joint inside a wall insulated with paper backed fiberglass insulation. I was scared of catching the paper backing on fire inside the wall. Sharkbite worked great.

 

[billt460]

Another old plumbers trick that works well, if you're having trouble with water contaminating the joint, is to stuff a piece of bread up into the pipe with the end of a pencil. Don't be stingy with it. It will stop water from being drawn into the heated joint, which will prevent a good flow of solder. After the valve is cooled turn on the supply, and open the valve with a bucket under it. What's left of the bread will be blown out almost immediately.

This worked very well for me when I was sweating new valves on my outside spigots. Also, when I installed new supply valves to both of my toilets.

 

[wtd]

Sharkbites are nice. I used them under my house to repair a joint that developed a leak and I couldn't get water to quit dripping where I cut out the bad joint even after three days. I also ended up using some pex line instead of copper which I really liked.

Wayne

 

[firemachine69]

Love shark bites where it's sketchy to use full heat.


Also, to make a repair union where water won't shut off properly.


They are expensive though, especially if you use valves.

 

[Doog]

Good soldered joints need to be clean, dry (no water anywhere) and hot. The valve should be in the open position and not overheated. You need to drain the line into the water tank completely and let it dry before you solder it. The inside of the joint on the valve needs to be cleaned and fluxed as well.

 

[andyd]

I have shut offs ahead of all the fixtures and the bathrooms. I try to make access panels to anything in the walls. I have replaced all the old valves with ball valves. The dishwasher and the water heater have unions as the last connections. My acidic water is tough on water heaters.!0 yrs is about it. I can go to Lowes or HD and have a new one in an afternoon