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1victorianfarmhouse 07-04-2011 08:49 PM

Copper Tube Soldering Problems
Okay, so I'm in the process of replacing some old valves in preparation for adding a new water softener bought from a contributor on this list.

I'm new at soldering, but have been soldering with electrics for decades, so it's not that different. Of more than three dozen joints I've made, I have two that are leaking. One leak is horizontal, the other is vertical. Not huge, but enough, especially since they are on the line that goes from the well to the softener.

With every joint I sanded the tubing and fluxed both the inlet and outlet. I use a basic propane torch and solder, both bought at Menards.

I heat up the joint, then let the solder flow into it, just like I've seen on several videos. On these two joints, after they leaked, I resanded, cleaned them with alcohol and refluxed them, but did not take them apart. It seems that no matter how hot the joint gets (other joints six inches away start to soften) , the solder doesn't want to flow into it.

What happened? Do I need to remove these two and start over from scratch?

Is it contaminated somehow?



Blue Jay 07-04-2011 10:20 PM

Sounds like you have water in the line where you are trying to solder. Need to get all water away from the area (at least 3" on vertical) not a torch made that will the joint hot enough/

1victorianfarmhouse 07-04-2011 10:33 PM

Interesting, and thanks!

I noticed the leaks once I turned the water on, should be interesting trying get the water out of the pipe now, it's about 6" vertical and 18" horizontal.

But now i know what to do...


kok328 07-05-2011 04:53 AM

You need to take them apart, clean up the mating surfaces and reapply the flux.
It's the flux that draws the solder into the joint.
P.S.- I always use MAPP gas instead of propane, it heats the joint up faster so as to not allow the heat to travel to previously soldered joints.

JoeD 07-06-2011 04:15 PM

You sanded the tubing. You should also sand the inlet side. Both surfaces need to be cleaned.

Redwood 07-06-2011 05:05 PM

Both surfaces need to be clean and fluxed and there can be no water present. It also helps to have an open valve to allow the pressure buildup from heating to escape....

Once wet it has to come apart for a complete do over....

1victorianfarmhouse 07-06-2011 08:55 PM

All fixed now. Thanks for the info! I did sand the tubing, both the inlet and outer, but didn't make it clear. The water got into the tubing when I removed an old pipe and some water spilled out of it onto the surface I was working on; I didn't realize some had gotten into the pieces I had prepped for assembly.


Bevix 07-07-2011 09:41 PM

Here's a tip for the water issue in horizontal lines:

Take some white bread (not that hippie 28 grain type--the bad for you Wonder bread type) and stuff a small plug in the line--not too much and not too tight. It will temporarily keep any water away from your joints and will flush right out with no issues once the water is back on. Works like a charm.

For vertical lines, I usually don't have much problem. The key is to open to lowest valve in your house (usually an outside hose bib) so that the system can drain completely. Open several faucets throughout the house, too. That usually completely drains the system.

Redwood 07-07-2011 10:35 PM

I've never shared my lunch with a pipe yet....

nealtw 07-08-2011 12:59 AM

bread, I'm sure the health dept. would love that.

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