How To Re-Solder A Copper Pipe Joint Without Removing It

Chloe Meltzer
by Chloe Meltzer

Having a copper pipe break is never a fun situation, but unfortunately, it happens occasionally. Although knowing how to fix any pipe in your home is a great skill to have, learning how to re-solder a copper pipe is even better. If you decide you want to re-solder a copper pipe, the best option is to do so without removing it from the wall. The only concern with this method is that you will need to use heat and avoid damaging anything around the pipe.

The best method of re-soldering a copper pipe join without removing it is to simply drain the water, then use some sandpaper, plumbers tape, and a soldering torch. Although this might seem a bit daunting, it is possible by following a few simple steps.

In this article, we will discuss the tools that you need to do this job and the steps to do it successfully. Additionally, we will share several more tips to ensure you have a job well done when you are finished.

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Tools Checklist

There are a few tools needed to complete this project. You might have some of them at home, but if not, they will be easily picked up at your local home improvement store.

  • Rags
  • Plumbers tape
  • Slip joint pliers
  • Soldering torch
  • Tube cutter

Materials Checklist

You will want to make sure you have all the materials you need to before starting this task. Although it is not a massive list of necessary materials, you may not have all of these supplies lying around your house.

  • Sandpaper (either cloth or 120-grit)
  • Copper fittings
  • Copper pipe
  • Soldering flux
  • Lead-free solder

Step 1: Drain The Water

Be sure to completely shut off the water at the main valve in your home. You also need to make sure you have opened up any nearby faucets and allowed them to drain completely. This is essential because if you do not drain the water, you will have a ton of water all over your work station.

It’s a good idea to turn on several faucets throughout your home after shutting the water off. This will help drain your pipes even quicker so that you can get your job started.

Step 2: Dry And Sand

You will want to dry the outside of the elbow thoroughly. If you do not fully try the pipe, then you will not be able to solder it because water and fire do not mix.

Then, using 120-grit sandpaper or cloth sandpaper, you should sand around the leaking joint. This sandpaper should be around 1-1/2″ wide and about six to eight inches long.

You can put it over the end of the pipe, almost as if you are shining a shoe. Do so from many different directions, and make sure that the solder is cleaned off. Any and all surface corrosion needs to be removed.

Step 3: Apply Flux

Apply soldering flux around the entire joint. This is essential because it helps to prepare the copper for soldering. You are essentially cleaning and removing any oxides and impurities from copper. Make sure that you’re getting around the entire joint, including in the nooks and crannies.

Step 4: Heating To Replace The Old Solder

This next step is the fun part, and it involves your soldering torch. If you are left-handed, you will hold your torch in your right hand, and vice versa. You should have a leather glove or cotton rag in one hand. You will need to heat the pipe with a torch until the old solder melts.

Try to have the flame facing towards the valve but away from any wall if there is one in the area. You should have a pair of slip-joint plyers in your strong hand as well. If you have to remove the old solder, you can keep heating it while turning it with your plyers.

This part can be a bit dangerous, so be careful when removing the old solder. Have a metal bucket or piece of cardboard to set it down on while it is burning hot. Remove the old solder with your leather glove or cotton rag.

After removing the old solder, go back in and begin heating it again. Keep heating the pipe, and then add the new solder until a shiny ring of solder shows all around the joint.

Step 5: Wait

You must let the pipe cool for at least five minutes. Do not attempt to push this any faster than that. Not only could you burn yourself, but you might disrupt the cooling process and need to do it all over again. While you’re waiting, take a break and clean up your workspace to make the time go quicker. That way, you’ll be less tempted to touch it and potentially hurt yourself.

Step 6: See If It Worked

Finally, you can turn the water back on. Let’s hope that your solder worked and that you stopped the leak! However, after you turn the water back on, you will want to check the pipes and watch them as the water runs through. If it appears to be leak-free, check again in a couple of hours.

Sometimes a bad soldering job will take a while to appear. So, over the next 72 hours, it is crucial that you take the time to check the pipe. If you don’t have any leaks, you did a great job!

If It Continues to Drip

Although you always hope it works the first time, sometimes this is not the case. Especially if this is your first time soldering a pipe, it may not happen the first time you attempt it.

If your pipe continues to drip, you will need to turn off the water again. Then, open your faucets to drain the line once again. The difference this time is you will need to cut out the whole elbow. Although this may seem irrational, it may be your only option.

Finally, solder in new fittings and check to see if it worked this time.

If It Still Continues to Drip

Even if you follow all of the steps and try your hardest, sometimes you can’t solder in the new fittings. This is often because there is a continuous trickle of water. Although it might be a slow trickle, it will still prevent the solder.

The first method of avoiding this trickle is to simply wait for the water to completely drain. If you do not have the patience for this, then there is a trick.

Step 7: The Trick

  • Replace the elbow with a tee with a threaded fitting soldered on one end. 
  • The open end can allow moisture to escape. 
  • This moisture will actually escape as steam.
  • Since the moisture turns into steam, you will be able to heat the joint enough to melt the solder. 
  • Once the pipe has cooled, then screw in a threaded plug. 
  • Use Teflon tape or pipe compound on the threads.

Tips

  • Put a piece of sheet metal between the joint and the wall.
  • Notching the sheet metal if needed.
  • Near your work area, be sure to spray water ahead of time.
  • You can use fire-resistant spray around the work area to avoid damage.
  • If you are working in a tight space, then you may need to work longer with the torch. Pre-soldered fittings do exist, and if needed, you can use these instead to avoid using a torch for prolonged periods of time. 

When To Hire A Professional

If you aren’t sure if you can do a soldering job or aren’t comfortable with it, then you may want to hire a professional. However, you can always attempt it first and then hire if it doesn’t work. When the professional is working on it, as for tips and try your best to observe what is going on. That way, you can do this on your own if the need ever arises.

If you don’t want to hire a professional, you can always call a friend or family member. Find someone who is more of an expert in the DIY world than you so that they can teach you their ways.


Related Questions

What exactly is soldering?

Soldering is a process of joining different types of metals together. The solder itself is a metal alloy. It is typically made of tin or led, which is melted using a hot iron or torch. It is best to avoid lead solders, as they are toxic. This heat creates an electrical bond with the copper pipe.

What can I hold a copper pipe with when it is hot?

Either use a pair of leather work gloves or even a large cotton rag. Do not use anything plastic. It will melt, and you will get burned.

What is the plumber’s tape for?

The plumber’s tape can be used to old the new solder in place if needed. Although it will burn off with the heat, it will allow you to use both of your hands while working with hot materials.

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Wrapping It Up

You can resolder a pipe without removing it just by draining the water, heating and sanding the pipe, and then applying the flux to it to clean it. Then, after you are finished soldering, you will want to check to make sure that it’s not leaking. If you cannot do this job on your own, it’s wise to call a professional or a friend for help.

Chloe Meltzer
Chloe Meltzer

Real estate agent and copywriter, originally from California. Chloe brings her real estate expertise into her writing to create effective and helpful home guides for you! When not writing or selling homes, she spends her time as a digital nomad traveling the world.

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