Introduction: How to Solder a Proper Plumbing Connection

Picture of How to Solder a Proper Plumbing Connection

In all areas of plumbing, it is very important to solder a good, clean joint. If you don't, there can be leaks of gases or liquids that flow through the pipe. So, in this instructable, I look forward to teaching you just that.

Step 1: What Do You Need to Solder a Proper Connection?

Picture of What Do You Need to Solder a Proper Connection?

Things You Need

1. Flux Paste

2. Solder (Lead-Free)

3. Steel Wool

Note 1: When you use the steel wool it is advised to wear gloves as to not get any metal bits stuck in your hand. You also need these because the propane torch is very hot and so is the piping after you heat it up.

Note 2: As seen in one of the pictures above, something that you can do is use a Car Battery Terminal Brush to make it a lot easier when scratching up the inside of the pipe that you want to use. In the comments below OmarJ3 also supplied information that when you go back to solder past works you can get one of these with a stem to make it easier to clean the pipe.

4. Sparker

5. Rag

6. The pipes that you are soldering


1. Propane Torch

2. Safety Glasses

3. Thick Work Gloves

Step 2: Prepping the Pipe

Picture of Prepping the Pipe

Prepping the pipe not only makes the pipe easier to solder but also helps the pipes hold together better by itself. To do this you must know that there are two different parts if a pipe. There is a fitting, and then there are the pipes themselves. The connectors are the larger bit of piping that the pipe fits into. For the fittings, you should use some steel wool to scratch up the inside (or you can use the car battery terminal brush as advised earlier). Then, use the steel wool again to scratch up the outside of the pipe. Finally, apply only a little bit of the flux paste to the end of the pipe. Connect fitting and pipe.

Note: In the comments below it was advised by tytower to only apply the flux paste where you want the solder to go. This is because the solder will go everywhere there is flux paste is. Thank you tytowers for commenting about this very helpful tip!

Step 3: Soldering the Joint

Picture of Soldering the Joint

So, once you have prepped the pipe, you are ready to solder. Turn the propane torch on, using the sparker to ignite the flame. Then, put the tip of the flame on the fitting and put it no closer. If you do, it will basically turn the flux paste to ash, and you need the flux paste to conduct the heat. Once the pipe looks hot enough (this can be determined by seeing if the pipe starts to discolor), put your solder up against the joint (the joint is the place where the pipe and fittings meet). If the solder melts, take the torch away from the piping and let the solder ease into the joint, all the way around. You do not need a lot of solder, so don't use too much. However, if you see a lot of excess solder that has formed, quickly wipe it with a damp rag before it hardens.

Note 1: In the comments below OmarJ3 supplied the helpful information that before soldering pipes together that have already had water flowing through them, make sure that all of the water is out. The heat will be sucked in by the water, not the piping. Also, referring to the same thing mtoddh recommended below too, in case there is a leak shove a piece of bread into the piping to stop it. When you turn the water back on it will dissolve and flush out the bread. Of course, it was also said by DaFoxx50 to make sure to use white bread, because whole grain won't dissolve. Very important. It would be very embarrassing to get all that way and to have piece of bread be your downfall.

Note 2: In the comments below dlemke advised that you should heat the fitting from the bottom, and the heat will spread to the top. Then, because solder jumps to the heat, put the solder on the top and it will spread downwards.

Step 4: Cleaning Your Joints

Picture of Cleaning Your Joints

So, when you are done you will see that the heat has probably messed up the coloring and dirtied some of the piping exposed to the flame (as seen above). When the piping has cooled, use the steel wool you used earlier to rub that off until the pipe looks as it did. You can get a lot of the messy stuff off but if there is any access, solder that has hardened, you are just going to have to leave it unless you want to heat the solder up again and wipe it off with a damp rag. However, if you do this if too much solder melts off you may need to apply more.

Note: It was advised by cdays_01 that after you are finished to add a little bit of flux paste to the metal and wipe it off to better clean it. However, if you remember, you could just brush it off with your finger while it's molten (you're wearing a glove).

Step 5: Step Back and Admire Your Work

Picture of Step Back and Admire Your Work

Thanks for reading my Instructable. Also, a shout out to my Dad is in order as he is the person that passed all of this useful information onto me, and worked with me until I fully understood the essentials of soldering. Also, thank you for all of the extremely helpful comments that people have left me below. It really makes me happy and interested to hear all of your tips! Please remember to favorite and follow!


JohnnieHammond (author)2016-11-19

Having a sink that is working properly is one of those essential things we forget about until we don't have one. Sometimes hair, grease, and other debris build up in your pipes causing your sink to drain slowly or stop up entirely. You should try doing trenchless piping from one of these service providers,, mrrooter, etc. it might clean up all your drain issues. Also any other plumbing problems, if any, would also be solved with this.

tytower (author)2016-09-21

Next step graduate to oxy accetylene torch and silver solder for a really reliable joint . Soft solder tends to not flow properly due to uneven heat in some areas leading to leaks in use.

kwhit190211 (author)tytower2016-10-25

Tytower, if you prep the copper first, paste the tube & the fitting both, heat the joint with propane torch, add solder the joint will hold pressure. The only time oxy accetylene & silver solder is used is when you are working on refridgerant lines. Silver solder is rarely used on city water. If you have to go back & work on it again, dealing with silver solder is a pain. If you don't know silver solder was used, heating with a propane torch won't get you anywhere, as propane won't get the solder hot enough to remove the fitting

tytower (author)kwhit1902112016-10-26

Just remember its a big world . here in australia we use it all the time and it is reliable . You don't go back because it does not leak or let go with vibration . Thats the point you have missed.

dlemke (author)tytower2016-10-02

Not many common areas have the need for silver solder joint. It is expensive and a lot harder to learn. You also will need a hotter heat source and silver solder paste.. No, I am not talking about brazing with rods that have a small percentage of silver. I have usually only found silver solder joints on high end govt. projects.

kwhit190211 (author)dlemke2016-10-25

Paste wise, no. You can use the same paste as you do with regular solder. You just need to use sil-fos as well.

kwhit190211 (author)kwhit1902112016-10-25

Well sil-flos might not require paste, but we always used it. For a few reasons, if you use it you don't have to worry about the Tube gualding in the fitting before it is set in the direction you want it to go. Cause sometimes the fittings did that. And also the paste kept the tube & the fitting shiney after you cleaned it. We used it all the time, worked better then the liquid crap.

dlemke (author)kwhit1902112016-10-25

Sil-Fos requires no flux. Sil-Fos is a brand name of brazing rod that is used in the refrigeration trade and has different amounts of silver from 7.5-35%. Using real silver requires it's own flux or paste as it is called. Regular solder whether it has lead or not, uses it's own type of flux. Silver based brazing rods are very expensive, so you can imagine what it would cost to use real silver solder joints on any project. The only example I can think of to use pure silver joints, off the top of my head is where you need to go from a ferrous metal to a non-ferrous metal.

Just for information purposes, refrigeration copper is not the same as plumbing copper. It is not only measured differently, it is manufactured differently to make sure there is no oils in the pipe left from the process that would mess with refrigeration oil.

dlemke (author)dlemke2016-10-25

Sil-fos™ is a silver-copper-phosphorus brazing filler metal, which is used to braze copper and copper alloys. When brazing copper, the phosphorus within the alloy imparts a metallurgical based self-fluxing capability.

Swiped this from a search engine to make it clearer.

tytower (author)dlemke2016-10-12

Silver solder joints are the plumbers preference in Australia . Perhaps
you do not have the temperatures and pressures we have . You are very
contradictory . I usually find that such all encompassing statements are made by people
who really have very little practical experience.

dlemke (author)tytower2016-10-13

I have a lot of experience soldering, brazing, and yes, even silver solder joints. The only place I can think of where I have to use actual silver solder is on joints that go from ferrous to nonferrous metals. More precisely, on compressors that have a steel outlet tube that has the copper plate burned off by someone getting it too hot. Manufacturers plate the outlet tubes with a thin layer of copper to allow the transition from steel to copper without using the more expensive silver. The copper plating on the steel tube is very thin and this can be damaged by using too much heat. Silver solder, which is very expensive and hard to find at most supply stores, can be used to do these repairs.

Through the years in the HAVC field, we have seen joints go from lead solder to self-piercing couplings, to silver content brazing rods. Brazing is much more durable and contains no lead, but the newer lead free solder requires less heat and is easier to use on water pipes. The cost is probably the main reason solder is used over brazing even with experienced plumbers.

I believe a lot of people confuse silver solder joints with brazing using brazing rods that contain varying amounts of silver. This is not a true "silver solder" joint. There are definitely some legitimate uses for silver solder joints, but not in general domestic plumbing.

My comments were merely meant to be informative. I did not want to offend anyone, and I hope you were not offended. It is easy to come off abrasive when making comments in a comment section. I probably need to edit myself more often.

nmleon (author)tytower2016-10-13

Most plumbers in the US don't have or use oxy acetylene rigs.

sbergeron2 (author)tytower2016-10-02

In many areas, especially in the United States, Soft solder is the only legal solder for sweated connections per building codes, though below slabs (for repairs only), brazing with an appropriate brass alloy is required

ShadowRoch (author)tytower2016-10-02

Good to Know. Thanks!

steveastrouk (author)tytower2016-10-02

That's precisely what defines a proper plumbing connection - if you heat it unevenly, without sufficient flame power, you get crappy joints. Care and experience delivers perfect joints every time.

kwhit190211 (author)2016-10-25

Nix to the steel wool for cleaning the tube. Use sand cloth instead. Much easier to use and easier to clean the tube of sand instead of the steel wool particles. To clean the fitting use the proper sized fitting brush. So much easier to use & much faster. After both tube & fitting is cleaned, use nokorode paste on both, join them together, heat, solder, wipe with a rag, go to the next joint & do the same.

cbowers18 (author)2016-10-02

Good work, ShadowRoch. It's especially impressive that when others
offered suggestions or corrections, you didn't adopt the attitude of "I
already know it all." I have three graduate degrees in two different
fields, and I don't "know it all" about either of them, far from it.

have one comment; the last picture shows you kneeling by your work; I
assume the picture was posed to serve as a conclusion. But you're posing
without the safety glasses you quite correctly recommend. You should be
shown doing what you say. That said, I look forward to your next Instructable!

frarugi87 (author)cbowers182016-10-10

Without too many words, "I know one thing: that I know nothing" [Socrates]

ShadowRoch (author)cbowers182016-10-06

Thank you. I really love to learn and really thank you for that compliment. It is one that really makes me feel happy. I do think people should be shown doing what they say, however, I am actually wearing glasses in the picture, you just have to look closely.

OmarJ3 (author)2016-10-02

This process can be frustrating when any part of the procedure is neglected. It used to be much easier when there was some lead content in the solder. Also, note that in existing circuits, any residual water must be drained, as it will absorb too much heat, and prevent flow of the solder. Also, one can buy a battery terminal brush with a "stem" that will scrub the insides of the fittings. This is important when re-using old fittings, or if the joint needs to be redone after a failed attempt.

ShadowRoch (author)OmarJ32016-10-06

Good to know. I had heard that lead solder was easier to use, so it's too bad that it isn't safe. I will add this stuff to my instructable! Thanks!

OmarJ3 (author)ShadowRoch2016-10-06

I've learned a few things from the "Instructables" website, so when possible, I will share my experiences which may help others. You are very welcome!

dlemke (author)2016-10-03

I want to commend you (and your Dad) for taking on this skill. It is not easily acquired and there are many trade secrets to make the job faster, easier, and more reliable. In the trades, you would preform this task many times and get much better at it, and will intuitively know when your joints are properly soldered. A good heat source is a must. While you can often get by with small propane torches, like the one you show, it sounds like you were not applying enough heat. Water pipe solder (lead free) is not as easy as free-flowing lead solder, which most of us use on our electronic projects.

You mentioned your glasses, but I don't see you wearing gloves. This is important, as skin burns suck, and you can also use the finger of your glove to quickly wipe your solder joints, as you apply solder to each joint and work your way through your project. It is almost impossible to do it right with a rag, and you don't want a wet rag, as it will could cool your project before you are done soldering. With a cleanly wiped joint, you will also be able to visually inspect the joint and see if you applied enough solder. You will learn how much is too much in a short time, but you need to make sure there is enough to completely fill the void.

One important detail, you should learn. Heat the fittings or the bigger stuff first. If you can only get your solder to melt by heating the pipe or tubing first, your torch is not hot enough. Turn it up, or find a better one. Start by putting the heat on the bottom of the joint (heat rises and you can see better), And apply your solder to the top, when the heat gets into range. It should happen fairly quickly, it will melt and you can watch as it sucks into the joints, filling up the cavity. Remember that your solder will follow the heat, and you want the joint to fill with solder, something that may not happen if you start by heating the pipe first.

While it may sound like I am being critical, it is not my intention. I am a service tech (HVAC) and while I will usually braze the refrigeration pipes I am installing or repairing, I have done a lot of water pipes. There are many more lessons to be learned, like working with older/used materials, working with bigger pipes and valves, and learning how to use heat sinks and shields to avoid damaging nearby materials, but that comes with time and practice. It looks like you have a good start on it. Working in the trades is now one of the best paying jobs, including many white collar jobs and it is satisfying work if you like what you do.

Always try new things, it is amazing what is at your fingertips......

ShadowRoch (author)dlemke2016-10-06

Also, I didn't catch that I wasn't wearing gloves. My dad and I would take our gloves off periodically because our hands would start to sweat. I guess we forgot to put them back on. Next time I do something like this, I will have someone take a picture of me with gloves, and then replace the other pictures. Thanks for catching that!

ShadowRoch (author)dlemke2016-10-06

Thanks! Also, you in no way sound critical! It is extremely helpful! I will add to my instructable. Thanks!

wmwinkle (author)2016-10-03

Excellent! I've been a putz at this for years. Now I think following this procedure I can make a good looking and solid joint. Thanks!

ShadowRoch (author)wmwinkle2016-10-06

I'm glad it was helpful.

Cowboys From Hell (author)2016-10-02

It's called sweating a pipe

Good to know. I will call it that in the future!

KSims2009 (author)2016-09-23

Good work, young man! Thanks for sharing your knowledge.

ShadowRoch (author)KSims20092016-10-06

Thank you. I really worked hard on not just having supplemental information, but also how I wrote it. I'm glad you think it's great.

Hightech_arduino (author)2016-09-21

very nice


Stan1y (author)2016-09-21

This is something I keep meaning to try, but any time I need to do plumbing I resort to compression fittings, you make it look straight forward I really must try.

ShadowRoch (author)Stan1y2016-10-06

I'm glad it was helpful!

mtoddh (author)2016-10-03

Great job!

Also another little tip for the case where you are repairing a pipe. Of course you should turn off the supply valve and let the water drain, but in case the supply valve still allows a very slight trickle of water past it, you'll pull out your hair trying to solder it... Shove a sizable chunk of bread into the pipe to temporarily stop the leak and quickly solder your joint. The bread will quickly flush out when you turn the water back on.

DaFoxx50 (author)mtoddh2016-10-06

Make sure you use white bread. Some bread have whole grains which may not disolve.

mikeyc.2009 (author)2016-10-05

The best tip that I got for making good, clean plumbing solder joints is to not use the flux that Home Depot sells. Go to a plumbing supply house and use what the pros use. I use Everflux.

tytower (author)2016-09-22

Only put flux where you want solder . It runs wherever the flux is

dlemke (author)tytower2016-10-04

This is not true. While the solder will need the flux, you should be able to control where the solder goes by proper application. The heat and capillary action will draw the solder into the joint. Doing vertical applications takes more practice and you will appreciate a clean joint, as you will be able to inspect it better to determine if you did it correctly. You also don't need to get carried away with the flux. Just liberally apply the flux to the mating surfaces, and no more. The excess when you put the joint together and apply heat, will show you how much you waste. You should have very little solder outside of the joint when you are done.

ShadowRoch (author)tytower2016-09-22

Good to know. I will add a bit to my instructable about that tommarow. Thanks!

cdays_01 (author)2016-09-21

One word of advice. You should heat about 6" of the pipe before the fitting. This gets the pipe warmed up and will promote capillary action. When I say "heat"; I mean run the torch up and down the pipe at a steady pace for 5-6 seconds. If you want to make your joint look clean; use the flux and brush the joint after you're done and then wipe with a rag.

dlemke (author)cdays_012016-10-04

I would not heat the pipe first. Put your heat on the fitting and be patient. Rolling the torch around the joint will help, but if you are good enough to not over-heat the joint with a good torch, you can just heat the bottom, as in many cases, you cannot get to the whole joint, like when it is against or near another object like a wall, etc... Do not brush the joint when you are done, just quickly wipe with your gloved finger while the solder is still molten, and you will be able to better see if you filled the joint and it also makes for a nice looking job.

ShadowRoch (author)cdays_012016-09-21

Good to know. I will add that.

LubieEst (author)2016-10-02


You have been an admiral son and your Pop should be very proud. The fact that you are learning and understanding what you are doing is a trait to be admired. To others who have seemingly scrutinized and criticized his work pointing out faults that he will learn over time but not from ridicule of effort, if you could done any better, YOU should have been the one to put up the instructable. OOH-RAH for this youth ....

snoofy (author)LubieEst2016-10-02

Great comment LubieEst.

loubee2 (author)2016-10-02

Hi, For decorative copper pipe soldering, there's a copper colored solder available, so it's not necessary to "paint" silver solder to disguise it. It may have been available all along, but it was new to me! I'm not affiliated with any seller & have to admit I haven't tried it yet. But if this is of interest, just do an internet search. It's easy to find!

PhilS43 (author)2016-10-02

Brave to describe a "proper" plumbing connection.

There are golden rules in doing end-feed as opposed to solder-ring fittings. A good end-feed joint is where craft comes into it - solder-ring fittings don't need a lot of skill, but for a neat installation, and cheaper, use end-feed.

Rule one is clean, undamaged copper tube and fittings. Don't use harsh abrasives to clean them, 3M Scotchbrite (pan scourers) give the best surface. Clean the tube and fitting to allover bright finish - clean the inside of the fitting with Scotchbrite by wrapping it around a toothbrush or similar - immediately cover the surfaces with a decent lead-free flux - don't use the old lead solders or the likes of Fry's Fluid - times have moved on.

Rule two is use a lead-free plumbing solder. Assemble the joint making sure that the tube is fully pushed in. Keep the assembly in a vice or whatever so that you can use two hands.

Rule three. Use a decent blowtorch. I will only use MAPP gas now, especially with pipes. Heat the fitting and pipe evenly all round and watch the colour of the copper - we don't want it going red. Dip the solder into the flux. Test it at the pipe-fitting junction. When it flows easily, go round the whole joint and let capillary action do the rest. A good joint will just have a ring of solder showing for about a couple of millimetres, no blobs or runs up the pipe or joint. Keep the fitting hot with a gentle flame while you do the other half or third of the joint. Let it cool naturally, but while still hot, wipe it with wet Scotchbrite to clean it up again.

If it's for a hot water system, test it under pressure with hot water - an experienced plumber told me that a poor joint on cold water will look OK when tested, but sometimes the flux is keeping it together.

Brazing or silver soldering are the next steps up and as said elsewhere needs a much hotter flame, oxy-propane, maybe not as hot as oxy-acetylene, but it opens up a whole range of possibilities beyond copper - don't forget, if your plumbing requires brazed joints, use fittings designed for brazing, generally much chunkier.

Lee Wilkerson (author)PhilS432016-10-02

MAPP gas is not true MAPP gas any longer. It is an adulterated mixture that will only attain a maximum of about 5% more heat than propane.

PhilS43 (author)Lee Wilkerson2016-10-02

Works for me. Bernzomatic torch and Bernzomatic or Rothenburger MAPP gas. Nice clean controllable flame and certainly hot enough to braze. Acetylene gives out a lot more energy than methane/butane/propane gases, so any substitute gases with a similar carbon hydrogen bond will work. Any extra heat is a bonus and I know many plumbers who won't go back to propane or butane. I don't how they get away with calling it MAPP if it's not.

About This Instructable



Bio: I was recently introduced to the beautiful world of making and have been hooked ever since!
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