Thread Number: 63081  /  Tag: Other Home Products or Autos
How to Braze Copper Pipes?
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Post# 856632   12/14/2015 at 21:55 (975 days old) by scoots (Chattanooga TN)        

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I have accumulated a number of washers that I want to put into use and I need to increase the number of delivery points in my laundry room. I realize that "this is what the internet is for", but does anybody have a favorite book or web site that will show how to braze copper pipes? - I just do not have several hundred/thousand dollars to throw at a plumber.


Post# 856634 , Reply# 1   12/14/2015 at 22:04 (975 days old) by wayupnorth (On a lake between Bangor and Bar Harbor)        

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I have found it is much easier to use a shark connector to the copper and pex pipe from there. Always no muss or fuss or leaking. I never could get copper to go together right soldering with a blowtorch. I recommend sharks and pex, my personal preference.

Post# 856645 , Reply# 2   12/14/2015 at 23:16 (975 days old) by Yogitunes (New Jersey)        

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I did this laundryroom all in copper at first......I hate to solder, but found it easier to use liquid flux, commonly used for car radiators, brush or spray it on, if you want to pursue that route.....

later I needed to add a station, and found these 'shark bites' a quicker way to add a set of valves, or even just to tap in and add a whole row of stations from there using PVC or Pex...


Post# 856652 , Reply# 3   12/14/2015 at 23:33 (975 days old) by kb0nes (Burnsville, MN)        

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Soldering (or sweating) copper tubing for water supply plumbing is quite easy once you learn a few pointers. Proper fitting of the tubing joints, insuring they are clean, adding flux and adequate heat will get the job done quickly in most cases.

If a picture is worth 1000 words, they 30 pictures a second is worth a ton more. I'd search YouTube for soldering copper pipe. I would Google the same and you are sure to find lots of great how-to info with visual aids.

Personally, I don't trust the Shark Bite style fittings (I realize it is likely paranoia, but humor me, we all have hangups). I do really like PEX though but only with the Uponor/Wirsbo ProPEX expansion rings. Lacking the tool to do this I would likely do all my plumbing projects in soldered copper. If your project is sizable the cost difference for copper will soon pay for the PEX tools though.

Post# 856658 , Reply# 4   12/15/2015 at 00:48 (974 days old) by MattL (Flushing, MI)        
Soldering and PEX

I too hated soldering pipes, until I learned the secret -- MAP gas.  Propane is just not hot enough, I often had leaks and bad joints with propane.  Now I have no issues soldering, it's a little more costly but well worth it.


As for pex, I use it and like it.  There is one trick you might want to consider, upsize it.  If you would normally run 1/2" copper, use 3/4" PEX, same with 3/4 copper use 1" PEX.  Why?  Look at the fittings - the elbow used in 1/2" PEX has a small diameter hole, about the size of a pencil - definite flow restriction. I mentioned this to several plumbers I know and they do the same.


Shark bite are great, I've used a lot of them and never had an issue.  PEX with crimp rings is fine too, I've used that a lot too, never an issue.

Post# 856697 , Reply# 5   12/15/2015 at 08:26 (974 days old) by Volvoguy87 (Cincinnati, OH)        

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I like soldering copper pipe. I find it somewhat therapeutic. I love looking at a plumbing job done by someone who really knew what they were doing, it's an art.

I like using type L (the thicker walled variety at most home centers). I run most everything in 3/4", and only use 1/2" for one thing at a time. In other words, I never tee off of a 1/2" line lest I have pressure problems. I like using 1/4 turn ball valves because they just work so nicely. I also like to insulate all the pipes to reduce noise and keep my hot water as close to "liquid fire" as possible.


Post# 856704 , Reply# 6   12/15/2015 at 10:06 (974 days old) by kb0nes (Burnsville, MN)        

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I secondnd the extra heat requirement over and above a simple propane torch. An important part of soldering is to get in and get out as quick as possible. A propane torch can work with 1/2" or maybe 3/4" but even with the smaller sizes once you use more heat (provided you can control it) you are spoiled.

MAPP gas was an interesting development, it gave near the performance of Acetylene but without the storage issues. Unfortunately we can no longer buy MAPP gas anymore since manufacturing has stopped. The MAP-Pro is really just propane with a higher concentration of propylene and it doesn't perform like MAPP did. Our "MAPP" torch at work with a MAP-Pro tank on it doesn't seem any different then propane :(

I do all my plumbing soldering with with an air acetylene torch. A few years ago I helped a couple friends plumb in lawn sprinkler systems and that torch was a godsend for the 1" pipe and fittings. Lovely not having to hold the tank and maneuver it into tight spots too.

Post# 856730 , Reply# 7   12/15/2015 at 13:20 (974 days old) by Tomturbomatic (Beltsville, MD)        

The thing about larger diameter pipe is that for long hot water runs, it holds more cold water that you have to get rid of before you get hot water. If you don't have a way to purge it, it winds up in the appliance cooling your hot water.

Post# 856870 , Reply# 8   12/16/2015 at 07:22 (973 days old) by combo52 (Beltsville,Md)        
Pipe Sizing For Home Plumbing

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Unless you have very poor water pressure 1/2" piping is about all you need in a normal home, and for hot water runs you never really need anything over 1/2".


My entire two full bath, dual kitchen, two outside faucets, and six washer hookups home in W Va. has no piping larger than 1/2" in it and it works fine. [ built in 1965 before water restricting plumbing fixtures were common ]


New Washers, DWs, faucets, shower heads all have flow restrictors in them that limit flow so much that you not only waste so much water trying to get hot water to where you want it but it also cools between uses. I have actually seen modern DWs installed with 1/4" tubing and they work fine and they get hot water to them very quickly.


John L.

Post# 856875 , Reply# 9   12/16/2015 at 08:39 (973 days old) by Volvoguy87 (Cincinnati, OH)        
Pipe sizing.

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I am a fan of bigger pipes, but your mileage may vary. I own a 4-family monster of a home which I have been restoring for a few years (and am finally nearing the end of the first phase). Right now, I have one water heater for the whole building, and it's in my personal basement near my laundry rooms. My fear is that if I am running 4 or 5 washers at the same time while a tenant or three are in the shower and doing their own laundry, someone will be on the receiving end of some wild temperature and pressure fluctuations.

My house has 2 water meters. One meter handles the cold water for one side, and the other meter handles the cold for the other side, and the hot water for the whole thing. One handy trick I put in is a thermostatic mixing valve on the water heater. I have the tank at 160 degrees, and the thermostatic mixing valve adds in cold water top temper that down to 120 for all the sinks and showers. The tank gets drained more slowly and I can handle 1 or 2 more showers off a 50 gallon tank. I am also installing a line off the 160 output before the mixing valve to supply "liquid fire" to a few washers and a utility sink. Sometimes I need hot water, and sometimes I need something more!


Post# 856904 , Reply# 10   12/16/2015 at 11:12 (973 days old) by sudsmaster (East of SF, West of Eden, California)        

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I agree... sweating (the term for soldering copper pipe) is pretty easy once you get the hang of it. If you know how to solder electrical stuff, it's even easier.


Like was said, clean copper (there are inexpensive special metal brushes for cleaning the outside and inside of pipe and fittings to be joined, good flux, and good solder. I haven't had a problem using regular propane. I have a nifty one piece torch with built in igniter. It has a jet head that mixes in plenty of air for a loud but hot flame. It's possible the newer lead-free solders have a higher melting point, I don't know. I think I used lead free last time with no problem, but that was about 10 years ago.


You want to heat the pipe around the area to be joined, not the solder itself. Once the metal is at the right temp, the solder should just flow into the joint and seal it.


A trick a plumber showed me: to solder into existing line, put some bread into the pipe(s) that might have water trickling out. The bread will stop the water from ruining the solder joint, and once you are finished the water flow will dissolve the bread. The same plumber keeps a damp rag handy to wipe off any excess flux after the solder has cooled.



Post# 860255 , Reply# 11   1/5/2016 at 15:19 (953 days old) by DaveTranter (Central England)        
A couple of points for hot water fans

I recall reading in an old (mid-century) book on plumbing, that there is a way of supplying a long run of taps/faucets with 'instant' hot water, by arranging the supply pipe to have circulating hot water in it. When not actively supplying water, there was a thermosyphon action in the feed pipe (which was arranged as a loop from the tank) to keep the water just behind the tap/faucet at full cylinder temperature. Good lagging is a must, of course, or it could cost a fortune to keep the supply hot.

If anyone is interested, I will see if I can find the book, and copy the diagrams. Apparently, this system was used by all the 'best' hotels at the time, to give 'instant' hot water in all the bathrooms/washrooms.

All best

Dave T

P.S. thanks for the 'bread' tip... That will be remembered!! I like soldering, both electrical and plumbing. Never tried brazing copper, though... Never worked with HVAC.

Post# 860266 , Reply# 12   1/5/2016 at 16:41 (953 days old) by Launderess (Quiet Please, There´s a Lady on Stage)        
Thermosyphon Hot Water Systems

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Were popular late 1800's through early 1900's. Mr. Vanderbilt's Biltmore estate in North Carolina originally used such a system.

Working upon simple physics one, two or even three tanks are suspended from ceiling. Cold water from mains feeds into tanks. Since heated substances rise while cold sinks the latter moves to the bottom of tanks while the former rises.

Cold water goes down to the boilers where via coil inside or indirect it is heated and returns up to tanks. This endless loop works without pumps and via simple gravity and again, physics. As hot water leaves the system (taps) cold water (from mains) goes into tank or tanks, sinks and the whole process begins again.

Because the water is in constant circulation you get "instant" hot water when taps are opened. Much like then and today where buildings with steam or hot water boilers for heating use a coil in tank or indirect, thermosyphon systems provided "free" hot water. That is long as you had the boiler running anyway why not put some of that hot water/steam to use.

This system worked well with coal fired heating because the boilers are rarely out of fire. However there are problems.

First using the boiler to heat water means you have to keep the water hotter inside to cope with heating cold water "and" providing heat. Next depending upon heating power of the boiler it could take hours or even a day to replace a tank emptied of hot water. This is why places usually had more than one tank.

Next worry comes from having to keep the coal boilers fired at a decent hot rate even during merely cool or even warm weather. With coal boilers many liked to shut the things down over the summer both to save on coal and keep from heating the place up.

To solve this problem there were "Tabasco" water heaters. These smaller boilers were used to provide water or steam heating for hot water systems. They could be used in place of a larger coal boiler during periods when that thing was shut off (summer), or simply as part of a building's heating plant in its own right. Again using a separate boiler to heat water allowed taking some of the work load off the main heating boiler so you could lower the water temperature inside.

Thermosyphon also worked with "range" boiler hot water systems. That is using the kitchen or whatever range (coal or wood burning) to heat water as well. Same sort of set-up in that you have a tank for storage and a flow of water circulating basically via gravity and or physics.

You also see thermosyphon hot water systems with solar hot water heating.

Without proper safety checks thermosyphon systems could be as dangerous as any hot water system. First of all unless hot water is drained out of the system regularly sooner or later there won't be any cold water in tanks. Then you have hot water circulating around and around. Next without some sort of mixing valve you could potentially end up with scalding hot water coming out of the taps.


Post# 860267 , Reply# 13   1/5/2016 at 16:43 (953 days old) by MattL (Flushing, MI)        

Actually, at the moment I am running a return line to my water heater to create a passive hot water recirculating system.  Having a two story house and a long run to the guest bath I'm tired of running the water for some time to get hot water.  Unfortunately the closest I can get to the  guest bath is about 25' as the last run is in a concrete slab. Regardless it will help in getting hot water quicker to the kitchen and the upstairs baths.

Post# 860293 , Reply# 14   1/5/2016 at 18:50 (953 days old) by combo52 (Beltsville,Md)        
Recirculating Hot Water Loops

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Are not too bad if only used in the heating season and all of the piping is in the heated portion of the home, but in most cases the cost saving of not wasting water in order to get hot water more quickly to the faucets is many times higher when you consider the heating cost in electricity or gas that is consumed keeping all that plumbing hot all or more of the time, and don't even dare to use such a system in an air-conditioned home unless the hot water pipes are insulated to at least an R value of 10 or more.


It is really better to insulate your hot water runs properly and make sure they are 1/2" or even smaller in diameter in some cases.


John L.

Post# 860331 , Reply# 15   1/5/2016 at 21:50 (953 days old) by hydralique (Los Angeles)        

Pump driven recirculating hot water systems are common in new construction and remodels and it's simple enough to use a proximity switch in the bathroom to turn the pump on when someone enters so that it doesn't run endlessly.

Post# 860366 , Reply# 16   1/6/2016 at 02:25 (952 days old) by sudsmaster (East of SF, West of Eden, California)        

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This house is single story, about 55' long. The water heater is in an enclosed patio about 15 feet from the front of the house, not too far from the kitchen. Unfortunately the water lines take a curious and circuitous route from the water heater to the kitchen sink. Just why, I don't know, but it's on my to-do list to redo the plumbing at some point. I plan on running 3/4 copper main lines from the street (cold) and the water heater down the length of the house, heavily insulated of course. Off that will be 1/2" branches to the various other destinations like sinks, washers, toilets, dishwashers, etc. This has the added advantage of replacing the old steel water pipe in the older parts of the home.


Although California is a relatively arid state, I still figure water costs less than the energy needed to heat it. So I've considered and dismissed the idea of recirculating hot water lines. It can take a minute or so for hot water to get from the heater to the bath at the rear of the house, but I just run the hot tap in the bath sink until it's hot before taking a shower. Probably will take longer with a bigger main water pipe as a trunk, but the trade off is not as drastic water a pressure drop or temp change when someone flushes a toilet somewhere else in the house, or the washer cycles its fills on and off (or so I'm hoping). And if necessary I could always add a recirculating circuit to the main hot trunk line.



Post# 860403 , Reply# 17   1/6/2016 at 09:06 (952 days old) by Volvoguy87 (Cincinnati, OH)        

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Recirculating hot water is a very nice feature and it can save the amount of water you waste running the tap to get the hot water to you. The way I would approach it is to definitely insulate the hell out of the pipes to start! The supply pipe can be whatever size it needs to be to move the amount of water required by what is connected to it. The return pipe, which usually has nothing tapped into it, can be 1/2". A circulation pump will keep everything moving, relatively slowly. Put the circulator on the return pipe near the water heater so it is easy to access.

Here's where it can get a tad more complicated: It may be a good idea to run the circulator on a timer. Set it to run only when you are most likely to use hot water. If you take a shower every day at 7:00 and leave for work at 8:00, have the circulator turn on at 6:45 and run until 8:00. Why pay for the electricity to run the circulator and the energy to keep the pipes hot when you won't need it?

In order to complicate things further, install a check valve on the return line in an accessible spot, like near the circulator by the water heater. With a check valve, if you use hot water while the circulator is not running, the system will function like a regular plumbing system. You will have to purge the water out of the plumbing to get the hot water up from the heater to your tap. The check valve will ensure the water is drawn only from the supply side, and does not draw from both the supply and return. This will ensure that you get hot water faster as you will only be purging the supply side, and not the return, and you won't be wasting the water in the return.

I'd also be curious to see if such a system could be activated via motion sensors in all spaces with hot water taps, but that could add a degree of complexity beyond what is reasonable.

Clear as mud?

Post# 860702 , Reply# 18   1/8/2016 at 11:52 (950 days old) by DaveTranter (Central England)        
Recirculating hot water

Glad to have started a discussion!! I read the 'Liquid Fire' comment (Reply#5), and thought this may be one way to achieve it. I know the original system I read about relied on a thermosyphon, but perhaps, in these days of small, cheap, easily available circulation pumps, a pumped (intermittent) system would be the way forward.
Here in the U.K. with our (mainly) tiny homes, distance from cylinder to point of use is seldom an issue. Also, (especially in rental homes) 'instant', or more correctly 'on demand' water heating via a 'combination boiler' is fast becoming the 'norm'. It's not a system that I would ever subscribe to, however, because in the event of an electric power outage or boiler breakdown, you have neither heating nor hot water!! :-( I still have a gas boiler, gas fires in two rooms, and an electric immersion heater in the cylinder in case it's needed... ;-))

All best

Dave T

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