Soldering vertical copper pipe

[bcarwell]

I have a vertical 3/4" copper pipe I just cut a section out of which froze and cracked. Now I'm replacing it with a new piece of pipe and two standard slip joints- one on either end. My question is how do you sweat solder when the joints are vertical ? I know how to solder and I know about capillary action sucking in the solder even vertically, and that you make the part hottest in the direction you want the solder to flow. But: once you've soldered in one side of the slip joint when soldering the other side won't it heat up the side you just soldered to cause the solder to flow out ? What order should I solder the joints in or does it matter ? Should I first solder on the slip joints onto the piece of replacement pipe at my workbench so I only have two joints left to solder when I put the replacement pipe in place ? Still seems like in doing so I'd be heating other side of the slip joint that I had soldered at my bench. And how long should the spliced-in piece of pipe be or does it matter ? Just a few inches long to replace all the bulged pipe where the crack was ?
Thanks for any tips (or reassurances if it will work just fine)...

Bob

 

[bcarwell]

Sorry for duplicate post. Can't figure out how to delete. If anyone knows, please tell me.

 

[sweettractors]

I would try doing the entire diameter at the same time and not front and then back? Preheat the entire area before feeding the solder in. Ken Sweet

 

[Kep]

Clean everything up put it all together start at the bottom and work you way up.

 

[daBear]

When you properly clean the copper pipe and put plenty of flux on it you will not have a problem. When heating one side I apply the solder to the other side. When it melts and sucks into the joint it flows all around. I remove the heat and slide the tip of the solder around the joint and it will still melt and flow. You will actually get more than you need doing it this way. One thing to watch out for is putting too much heat on the joint and evaporating all the flux which is not a good thing. It makes absolutely no difference if the joint is vertical. Once you see the joint suck solder, you are good to go.

 

[Jay4200]

I have a vertical 3/4" copper pipe I just cut a section out of which froze and cracked. Now I'm replacing it with a new piece of pipe and two standard slip joints- one on either end. My question is how do you sweat solder when the joints are vertical ? I know how to solder and I know about capillary action sucking in the solder even vertically, and that you make the part hottest in the direction you want the solder to flow. But: once you've soldered in one side of the slip joint when soldering the other side won't it heat up the side you just soldered to cause the solder to flow out ? What order should I solder the joints in or does it matter ? Should I first solder on the slip joints onto the piece of replacement pipe at my workbench so I only have two joints left to solder when I put the replacement pipe in place ? Still seems like in doing so I'd be heating other side of the slip joint that I had soldered at my bench. And how long should the spliced-in piece of pipe be or does it matter ? Just a few inches long to replace all the bulged pipe where the crack was ?
Thanks for any tips (or reassurances if it will work just fine)...

Bob

Don't worry about it. There isn't much that is easier than soldering copper. Solder doesn't 'flow out' of a joint. Just heat and poke. You can splice in any length you want, down to leaving 1/8" between couplers.

Use emery cloth and sand the inside of the couplers and outside of the end of the pipe until they are bright. Apply flux liberally and make sure all mating surfaces are covered. If you clean and flux a joint properly, a leak is virtually impossible.

I like to run the torch around the coupling and melt the flux, just to get any glops out of the way before I start to stuff in solder. Heat the front of the fitting and hold the solder on the back (bend the solder in a 'U') at the coupler/pipe joint. When the solder begins to flow, remove the heat and stuff the solder in - you don't want to overheat the joint. When a drip falls out of the joint, it's done. Solder doesn't 'move to the heat' as is the axiom - you heat from the other side because but once the solder side is hot enough to melt, the whole joint will be hot enough to accept the molten solder all the way around.

Once the joint drips, I usually make a quick pass with the solder around the joint to form a fillet, then immediately wipe around the joint with damp rag while the solder is still molten to fling off any excess solder and drips and make a clean looking joint. Once the solder solidifies, wipe the whole joint down vigorously with the rag to remove any remaining flux.

Do the bottom first on a vertical joint. It'll take about 1" of solder per side until it drips out. Also - solder an entire coupling at once, heat n' stuff on one side, then re-heat and stuff on the other. Then wipe. Also, prep, flux, and install the entire run before soldering. Do all of the soldering at once. Since you are only doing two, get it installed, solder and wipe one joint, then do the other. Done.

JayC

 

[/pine]

The key to soldering is heat...liquid solder will draw to the heat...as others have said...

don't try to melt the solder with the torch, allow the metal on the opposite side of the torch to get hot enough to met the solder and it only takes a small amount of solder.

When replacing sections...sometimes it is easiest to take a small file/blade and remove the "stops" inside of a copper coupling...this allows you to slide the couplings above and below the cuts...then cut your section in, flux everything and slide the couplings so they center on the joints...then solder

 

[Molerj]

When replacing sections...sometimes it is easiest to take a small file/blade and remove the "stops" inside of a copper coupling...this allows you to slide the couplings above and below the cuts...then cut your section in, flux everything and slide the couplings so they center on the joints...then solder

Great tip, Been soldering a long time & I never thought of that.

 

[Lightnsound]

You can get " non- stop couplers" at the plumbing supply store. They come without the stop nib and you don't have to file anything off.

When sweating pipe, make sure the line is vented and everything is nice and dry as well as clean. Water running into the flux can make it difficult. If the pipe is sealed at both ends, the heat will expand the air inside. This pressure can push the solder out of the joint.

 

[oliver1555]

Another little trick - Sometimes when sweating on an existing line, water will run in and cause problems. Even a few drops can be a pain. To keep unwanted water out of your joint, take a piece of bread and roll a chunk into a ball. Shove it up inside the pipe and make your connection. Any drips that come in will be absorbed by the bread and not go into your work area. When you put it under pressure again, the bread will become saturated and dissolve.

 

[kidr]

The key to soldering is heat...liquid solder will draw to the heat...as others have said...

don't try to melt the solder with the torch, allow the metal on the opposite side of the torch to get hot enough to met the solder and it only takes a small amount of solder.

When replacing sections...sometimes it is easiest to take a small file/blade and remove the "stops" inside of a copper coupling...this allows you to slide the couplings above and below the cuts...then cut your section in, flux everything and slide the couplings so they center on the joints...then solder

Couplings are sold with no "stops". Ask for a repair coupling.

 

[Scotty370]

bcarwell- Do you have any "end-play" at all? These (relatively new) "Shark-Bite" couplings are the cat's-butt, for repairs like this! No soldering, and removable, and reuseable! Pricey? Yes, but well worth the money if you can get them to work, with your application. Available at Lowe's, Home Depot etc. I'll try to find a link......~Scotty

Here ya go: http://www.sharkbiteplumbing.com/?gclid=CMDCgpeYgacCFQJN4Aod1TCieg

 

[/pine]

Couplings are sold with no "stops". Ask for a repair coupling.

I'm aware of this and I started to mention them...but many that read this thread will not be able to find them at the box stores and many local hardware stores...

FWIW...the couplings that only have a couple of little bumbs...a good pocket knife will shave the bump right off...

 

[ray66v]

You can get " non- stop couplers" at the plumbing supply store. They come without the stop nib and you don't have to file anything off.

You can also get a "repair pipe" where the entire piece (12") is sized to fit over the original pipe. These are designed for fast repair of frozen pipes.

kidr, I solder a lot of pipe. The best advice I have is to upgrade to a Mapp gas torch, (they use the yellow tanks sold right next to the blue ones). It is much hotter than propane, and that makes it easier, and faster.

Watch for the flame color to change to green, when that happens, time to apply the solder, and then get off of it.

Use the "tinning flux", and if your solder is old, it does not work well. Buy some new solder, and compare, you will be surprised at the difference.

 

[kenmac]

Apply heat to the fitting. Not the pipe itself. It's really no big deal.

 

[dstig1]

I think the question you are asking that is not getting answered is the order in which you work joints. Heat rises. You want to start with the bottom-most joint, and work upwards. If you go the other way, the heat rising up from working the lower joints can make the solder in the upper joint melt and drip out. If the joints are close together like a coupler, you still need to be careful not to overheat it or you can still run into problems.

Repair couplers without the internal bump/stop are readily available at the big box stores too, if that is what you need.

 

[/pine]

...Heat rises...

This is a common misconception...heat does not rise...heat moves from hot to cold.

Hot air (and most other gasses) rise...

when soldering copper the solder will always flow toward the direction the heat is being applied...up or down it doesn't matter...

 

[dstig1]

Technically, sure. Or if you like, cold moves from cold to hot But there are always multiple modes of heat transfer going on...including convection. Try going from top to bottom and bottom to top on order of soldering the joints and see which works better...BTDT

 

[Damifino]

I have a vertical 3/4" copper pipe I just cut a section out of which froze and cracked. Now I'm replacing it with a new piece of pipe and two standard slip joints- one on either end. My question is how do you sweat solder when the joints are vertical ? I know how to solder and I know about capillary action sucking in the solder even vertically, and that you make the part hottest in the direction you want the solder to flow. But: once you've soldered in one side of the slip joint when soldering the other side won't it heat up the side you just soldered to cause the solder to flow out ? What order should I solder the joints in or does it matter ? Should I first solder on the slip joints onto the piece of replacement pipe at my workbench so I only have two joints left to solder when I put the replacement pipe in place ? Still seems like in doing so I'd be heating other side of the slip joint that I had soldered at my bench. And how long should the spliced-in piece of pipe be or does it matter ? Just a few inches long to replace all the bulged pipe where the crack was ?
Thanks for any tips (or reassurances if it will work just fine)...

Bob

Bob, seems per your post, you already have repair couplings, at least that"s what I read into it.
Since as you stated, you have soldered before knowing about preperation, 90% of success in my opinion, just apply the heat holding to hot part of flame at center of coupling.

Then when temp is ready apply solder at top joint and then apply to bottom joint, go all the way around the joint, also for a clean looking joint, have a wet rag to wipe the excess solder that runs down the pipe.

Also a note to those who say to file the stop out of the coupling, these days the stop is made by stamping the o.d. of the coupling forcing the material to form a ridge on the i.d. of same, filing this ridge diminishes the wall thickness at this point, possibly future leak as this creates a weak spot.

 

[Molerj]

Also a note to those who say to file the stop out of the coupling, these days the stop is made by stamping the o.d. of the coupling forcing the material to form a ridge on the i.d. of same, filing this ridge diminishes the wall thickness at this point, possibly future leak as this creates a weak spot.

Another interesting point, thank you.