Copper joints..?????????

[Squints2See]

Quick question,

When soldering copper pipe joints, will a bad sweating job show up right away once its cooled down and youve tested for leaks? If there are no leaks, does that mean that the joint is good and will be stable, or can you initially have a leak free joint and in the future have a failure due to poor sweating technique? Just wondering, as I have a few joints ive done during a bathroom install that are not to pretty, as I tend to always use a little to much solder :p .......but after testing appear to be leak free...

Thanks for any input given.

Todd

P.S........One more question, Will copper water supply pipe always seem to be damp on the outside of the pipe, or should it feel totally dry?

[Gary Swart]

Unfortunately, a poor joint may not show up immediately. The best thing to do is to make absolutely certain it is a good joint to begin with. That means clean the fitting and pipe well just prior to soldering, making sure you flux well, and that the joint heated joint melts the solder and not the torch. That means you can have no water in the pipe, because that will prevent the flow of the solder. You must also make certain the joint does not move until it has cooled and do not force cool it by pouring water on it. Wipe with a damp rag to clean the excess flux, but don't drown it. In other words, just do it right. I had the main shut off valve (1") come apart 3 years after licensed plumbers installed a new supply line! All I did was lean against it. Moisture on a pipe can be condensation.

[Squints2See]

thanks for your reply,

to be more specific, sometimes, especially with 3/4" pipe, after heating the joint and removing the flame to apply the solder, the joint only stays hot enough to get the solder around half the joint and I have to reheat the joint to get a full visible bead around the connection. I know they say its not good to reheat joints and to do all same-joint connections at the same time but I am not that fast with the solder to accomplish this. Why does reheating the joint cause a problem? Also, what happens if your overheat a joint, and how do you know if you have done this?

Thanks,
Todd

[Terry]

It's all about heating the fitting and pipe evenly.
You will need to hit different spots on the pipe and fitting to get that effect.
Sometimes I will hold the flame on the opposite side to where I touch the solder.
I wish I had pictures of fittings pulled apart that show cold unsoldered stripes on the inside.

[hj]

What the solder connection looks like on the outside has absolutely no bearing upon what it looks like inside or whether it is a good joint or not. I have seen beautiful looking joints that had almost no solder at all inside the joint. There is no way to determine if a joint is good or not without taking it apart, so you just have to be meticulous in your preparation, and then ensure that the joint is heated properly so the solder will flow as required. If that is done properly, you can apply the rest of the roll of solder to the "bead" portion of the joint and make it as unattractive as possible and still have a good joint.

[Gary Slusser]

thanks for your reply,

to be more specific, sometimes, especially with 3/4" pipe, after heating the joint and removing the flame to apply the solder, the joint only stays hot enough to get the solder around half the joint and I have to reheat the joint to get a full visible bead around the connection. I know they say its not good to reheat joints and to do all same-joint connections at the same time but I am not that fast with the solder to accomplish this. Why does reheating the joint cause a problem? Also, what happens if your overheat a joint, and how do you know if you have done this?

Thanks,
Todd

Maybe I'm not understanding you correctly but... You should not remove the heat until your joint is fully soldered. When the solder starts to melt and enter the joint, move the heat away from the tubing end of the fitting to the other end and apply the solder on the other half of the fitting, where the flame was, that you haven't soldered yet. Then remove the heat and don't disturb the joint until the solder solidifies. Practice by then cooling the joint in water etc. and then unsolder and inspect the joint for total solder coverage in the fitting and on the tubing; no bare spots on either says a good joint unless the solder would have been stressed as it cooled.

Gary
Quality Water Associates

[RioHyde]

I just put in a new water heater for a customer yesterday in which I changed locations and had to repipe over to it. This is a house that was built in 1965 and has copper waterlines throughout. After repiping the hot and cold and hooking up the waterheater I turned on the water and what do you know.....had three leaks on the original piping. As I said, this house was built in 1965 and there were no leaks when I started. For 40 years all this copper held together. I unsweated the fittings where the leaks were and found on two of them that the copper tubing was only in the fitting about 1/8". On the third leak I found that while the tubing was all the way in the fitting, solder was only around the lip of the fitting. Goes to show you that leaks can occur on a sweated joint that one "thinks" looks good.

Rio