Solder or braze...copper rod or Silver rod?

[Mikebarone]

HI, I need to join a 1†copper line using standard copper fittings. One of these splices will be in an attic, and the other one will be under the concrete house slab.
I have been told that a normal solder connection will be fine. I’ve also been told to braze them together using a copper phosphorus rod. And then I have also been told that I need to braze them together using a Silver solder rod. Depending on what I need to use, will Mapp gas work? Thanks, Mike

 

[Jimbo]

Soft solder using a propane or Mapp torch is sufficient for the connection in the attic. Underground should be silver-brazed using an acetylene torch.

 

[Sponsor]

 

[Mikebarone]

Thanks Jimbo for the advice. You wouldn't happen to know what's the difference between the copper rod and the silver solder rod?

 

[Cass]

One contains 45% of silver melts at 1020 F and has a tensile strength of 120,000 PSI the copper rod melts at 1450 F and has a tensile strength of 40,000 PSI.

 

[hj]

connection

If you are making a connection under the slab, you could be setting yourself up for a future repair job. Silver solder/brazing severely weakens the fitting and the copper tube. The joint will not break, (which could happen with conventional solder), but the fitting itself could.

 

[Mikebarone]

Thanks Hj

Thanks Hj,
I read the same thing, that the high heat does more damage to the fittings and the pipe then good. So what would be a good repair for this situation? This sounds like, Damn if I do, and damn if I don’t.

 

[Cass]

Pack joint couplings work great and silver solder will work under ground. I would go with the pack joint couplings.

 

[Bob NH]

If you MUST do a connection under the slab, then I would consider doing things that would increase the chances of survival. No guarantees.
1. Use a high strength solder such as 95/5 tin/antimony or one of the silver bearing solders, selected on the basis of strength. Use lead-free if it is a potable water system.
2. Make provision for expansion and contraction by avoiding long runs with anchoring that will prevent motion of the pipe. Some kind of soft material at elbows and tees can provide some "give" if the length changes so the tension in the pipe is minimized.
3. If there is risk of corrosive soil, you might want to coat the joint area with roofing cement.
4. Consider the added margin of using Type L instead of Type M if the cost difference is not too great.
5. See if you can find 20 ft lengths instead of the 10 ft lengths at HD, if that will minimize joints.
6. Consider using a high quality plastic pipe designed for the service, or a length of stainless with welded fittings on the ends. You can probably get Schedule 10 or Schedule 20 stainless.
7. Consider using a sleeve if you can address the problems with sleeves described at the link below.

Following is a link to description of failures of copper pipe under concrete. Failures are not limited to the joints.
http://www.toolbase.org/Docs/MainNa....pdf?TrackID=&CategoryID=1289&DocumentID=3067

 

[Mikebarone]

Thanks to everyone!

I want thank everyone for all of the information and suggestions on my dilemma. I just joined the forum last night and everyone is so helpful!

 

[hj]

fitting

I would use a flare connection at that point. But is it a repair or a connection for a new system?

 

[Mikebarone]

It use to be where the water came into the house from the water meter. The owner opened up the front of this location for a room addition. Now the water inlet, is in the middle of the new room. I tried to talk the new owner into just putting a water fountain over it, but he didn’t like my idea…(just kidding).
I have already relocated the incoming water into a different location , by-passing the old incoming line. Before we took down the wall, it appeared that it was just one 1†copper water line going into the wall, supplying the house. After we took down the wall, we found that the 1†water line was split into two lines. I think one line might have gone straight to the hot water tank, and the other line supplied the rest of the house with cold water. Because I have already established an other incoming water line, I thought all I would have to do was cap the old one, below slab. Now that the wall is down, I see I have to join the two lines together….below grade.

 

[hj]

joint

Flare, and maybe with brass fittings and nipples, is definitely the way to go.

 

[Mikebarone]

Thanks hj

Problem....The home owner talked to (what he says was an experienced plumber) that works at Home Depot and he told the home owner that Silver soldering was code….and it just might be.
I’m really good at soldering with regular solder connections, (If I must say so myself, because no one else will) so I’ll give the silver solder a shot…wish me luck, skill, and high heat.
I am going to put in a metal trap door over the location of the connections, so if he discovers down the line that he has a leak somewhere, (by doing a pressure test on the line) he could always check out the connections. This way too, the fittings will have a little give to them and hopefully this will help.
Thanks again for all the time you, and everyone else, has taken on my problem! I’ve really learned a lot. I’ll have to let everyone know how this turns out, (only if it becomes a success story).

Mike

 

[Cass]

A pack joint coupling will out last a silver solder joint any day.

 

[hj]

joint

"Experienced plumber", "works at Home Depot"? Impossible. It has to be one or the other. Silver solder under floor is the "code" but that does not make it desirable. I never trust a rubber pack joint for hot water, although this being cold water it would probably last. One problem you will have is getting the pipe hot enough to silver solder, or even soft solder, it down in a hole under the floor. The burned gases will limit the temperature and time the torch will burn before putting itself out. You either need an oxy/acetylene torch, which has its own air supply and hotter flame, or a blow dryer circulating the air in the hole to bring fresh oxygen to the torch.

 

[Mikebarone]

Thanks hj

Damn hj…I can tell you’ve done this once or twice before! (LOL)
Good point on the available oxygen in the hole. As far as an oxy/acetylene torch…if I shelled out the money to get one, I probably wouldn’t use it again. I can, (for about $50.00) get a oxy/mapp set that I would probably use more often. Do you think that the oxy/mapp set would work, or do you think I’m just being penny foolish, by not just spending the extra money, and just get the oxy/acetylene torch set?

Thanks, Mike