Unsoldering copper water pipe junctions

I've tried propane and then MAPP gas to unsolder one half of each of two copper junctions** and it doesn't seem to get hot enough.
I also have a torch that uses 12 inch tanks of propane and of oxygen. Will that get hotter than MAPP gas and is it appropriate to use?
Or what should I do?
The open end of the pipe points down and I had hoped the connector would just fall off when it was hot enough. When that didn't work, I put some needlenose vicegrips on the connector to increase gravity and to pull and twist, but the solder didn't seem to melt. I had no trouble getting it evenly hot when I soldered it together in the first place.
As am aside, when I heated the area, on all sides to the extent I could do that, with MAPP gas, something dripped from the joint. At first I thought it was solder, but it was a clear liquid. Was it water from the combustion? There were 10 or 20 drops a minute.
**Is that the right word, where an inch and a half long outer tube is used to splice two pipes together, end to end.
I have a couple 3/4 inch copper water pipe junctions, straight connections, in which there is not much available pipe left on one side, and rather than cut off the part that is soldered, inside the connection pipe (I forget what that is called) I cut the connection in the middle, intending to heat and remove the outer layer next. But I can't seem to get it hot enough for it to come loose.
Thanks
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The water dripping from the joint was not from combustion, it was from some other source, and it is likely cooling the joint so the solder will not melt. What you have is a "coupling". I am wondering what you used to cut the coupling in the middle, and am a little concerned that you might have really distorted it when you cut it. MAPP is plenty hot for what you are doing, but the oxygen torch would be hotter still. It is unlikely to fall off by itself. I would try to wiggle it with a channellocks to test when you have the solder melted enough to pull it off.
JK
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Yes, water is the culprit. That MAPP gas torch will get a thin copper fitting so hot that it will distort as you try to pull it apart.
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Also fastening vicegrips to it is a bad idea, as that will act as a heat sink. Get rid of the water. Just cut the pipe and replace a section if that makes it easier to get rid of the water.
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marson wrote:

You should try shoving a ball of bread a few inches up the pipe to stop the water drip.
But, I suspect what's plaguing you is the growth of intermetallic compounds in the solder which have a higher melting point than the solder originally had, andd they tend to jam up the joint.
Like someone already said, heat it up and use channelocks to see if you can get the coupling end to rotate. It may squeek like a rusty hinge if there are intermetallic componds there, but if you can rotate it you can probably "twist and pull" until it's off.
Jeff
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Jeffry Wisnia
(W1BSV + Brass Rat \'57 EE)
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make sure there is no water in the pipe

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