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Sweating copper pipe - what was I doing wrong

17K views 26 replies 15 participants last post by  Steve_P 
#1 ·
Tried my hand at soldering some end caps onto a 1/2" copper pipe yesterday.

As far as I can tell, I did the cleaning OK and put enough flux on. But when the solder melted, it just beaded up and dripped off the pipe. Hardly any stayed on the pipe.
 
#6 ·
Tried my hand at soldering some end caps onto a 1/2" copper pipe yesterday.

As far as I can tell, I did the cleaning OK and put enough flux on. But when the solder melted, it just beaded up and dripped off the pipe. Hardly any stayed on the pipe.
sound's like the pipe was not hot enough? If it was blue you got to much heat and you will have to start over. Like resanding the copper and inside of the cap. If you didn't do this. That could be the problum also. You have to heat both at the same time only the cap a little more. It is a bigger item on the pipe. Did you tin the pipe? How to do that ? heat the pipe and flux and than solder so that it get's shinie Now at the same time take a rag and wipe the pipe. Watch so that you don't burn hand. Now the pipe is ready to be solder to the cap. Now heat both tell you see the solder on the pipe start melt than add solder to the cap area . you will see the solder flow into the cap. Now use a little lite flame when doing this . What you are doing is heating up both pieces so the solder will flow both direction's . Let it cool by itself . It should look shinnie . Now maybe some solder will drop off when you are doing this but that is ok the solder that you put on is going to where it should be going now. good luck been around soldering all my life. just a little learning curve Also they make a slip on conector no soldering required . These are at the box stores Shark bite is the name.
 
#8 ·
clean the outside of the pipe till it shines
Clean the inside of the fitting till it shines
flux the outside of the pipe and the inside of the fitting
apply heat till the flux bubbles then the solder

If it blows out its because you can not solder a sealed pipe. the air inside heats up, expands and blows the solder out. You need to relieve the pressure
 
#9 ·
like NHMaster :notworthy: said caps close the system so IMO are the hardest thing for diy'ers to sweat on. If you still have problems after recleaning and fluxing, consider using something like ball valves instead. If the caps are temporary, consider sharkbite caps :eek: (It's the only time I'll ever recommend em)
 
#10 ·
shark bite been around 10yrs

here is one site to read. their are many These have been around 10yrs. They are made in australia . with a garrentee. So don't knock them. Do a google search and find out lot's of good thing's .You can't use them in the bath tub fill spout . Because it will just keep turning but won't leak . But you will not be able to get it off. You need to compress the plastic piece to release the gripper's. Other than that all is ok. They have stop valves now also. here is a link http://www.ridgidforum.com/forum/showthread.php?p=81743
 
#13 ·
Wow. That's a lot of responses. Thanks everyone!

The system was open and the lines were dry. The water supply to the house was off and all the taps were open.

I read about the SharkBite fittings, but really wanted to learn how to solder copper pipes. The SharkBites were my backup plan.

Here's a some more detail about what I did. I used an emory cloth to clean about an inch all around the end of the pipe, and a wire brush to clean the inside of the cap. Then I applied flux to the end of the pipe and the inside of the cap. I put the cap onto the pipe. I held the solder to the top of the pipe/cap, and ran the torch all around. When the solder melted, it mostly just beaded up and dripped off.
 
#14 ·
It's good that you wanted to learn to solder, too many want the easy way out these days. Like someone said above, make sure other faucets nearby are open, maybe stick a shopvac on the pipes you're sweating to get all the water out then give it another go. As long as the gases have a way out, it should sweat on pretty easily. Good luck, leave them sharkbites at the store :yes:
 
#23 ·
It's good that you wanted to learn to solder, too many want the easy way out these days. Like someone said above, make sure other faucets nearby are open, maybe stick a shopvac on the pipes you're sweating to get all the water out then give it another go. As long as the gases have a way out, it should sweat on pretty easily. Good luck, leave them sharkbites at the store :yes:
You the man I agree leave the bites at the store learn how to solder. nothing like a solder joint.
 
#16 ·
IMO, bread is the last option. Get the water out if you can, why do anything that can contaminate your potable system. If you have to use it, get the cheapest white bread you can (wonder bread or store brand). No whole grains, pumpernickel, or even wheat. Keeps the chance of clogging aerators and valves to a minimum
 
#17 ·
I didn't think to mention this before, but when I am learning a new skill I try to find a way to practice first. Since you have had some trouble, try taking a short piece of pipe and a fitting- coupling, end cap, whatever- and practice at a work bench. That way you can be comfortable, have plenty of light, etc. Not trying to squeeze in a corner, on your knees in a crawl space with a flashlight, etc. Take all the variables out of the picture and when you get it right you will know it. Just spend a couple of bucks for a 1 foot stick and a couple of fittings or just use the ones you already have. Some people discourage re-using fittings, some just clean them off and go again.
 
#19 ·
From your lasr post "I put the cap onto the pipe. I held the solder to the top of the pipe/cap, and ran the torch all around."

If you did in fact touch the solder to the pipe prior to heating it the cap(and pipe beneath the cap) then the solder would run off as it has a lower melt temp. As one of the posts before said - after cleaning and fluxing, put the cap on, heat it at the end and as another post said - after about 10 seconds - more or less depending on your heating source, start touching the solder - tapping it on the pipe near the joint . If the copper doesnt "suck" into the cap - heat a little longer.

If you can't get the solder to melt this way, there is most likely some water - somewhere close to where you are heating thats being drawn to the heat and preventing the pipe from reaching the melt temp for the solder. So use the white bread (no crust) to plug the pipe and soak up any water as you heat things up. Push it in a ways too - it all comes out later. And if you're using standard hardware store propane, Use the hotter burning stuff - Yellow canister usually. MAP or MAPP. make sure your torch is ok for it as it burns hotter. It should be though.
 
#27 ·
what jack of many said....

I am sure there are 500 videos on youtube showing this. But, like others said, I learned (pre-internet) by using some tube scraps in the vise in a more "controlled" learning environment. It is not that hard- it's not like learning to weld. But, as said, you must have the pipe drained. You shouldn't have any more trouble with caps than any other fitting- at least I don't, and I'm not a pro. Primarily heat the fitting with the torch and I like the MAPP gas but unsure if it's still available? when done let it cool a bit then wipe down the soldered area with a damp rag to clean any flux residue off.
 
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