sweating

I have only worked with 1/2" copper pipes. I would like to know if there are some things I need to worry when sweating a 3/4" or 1" copper pipes, or are they the same?

This is for my preparation for the lawn sprinkler system project in the future.

Any help would be greatly appreciated.

Thanks!

They are the same, but since the fittings and pipe are larger, they take more time to heat up.

A little emory cloth helps to clean the pipe where it will be going into the fitting and some good flux.

I like using Bridgit® Nickel-Bearing Solder

http://www.jwharris.com/jwprod/solderalloys/#1

A quote from their site:
Bridgit caps like no other lead-free solder, and its wide plastic range of 170°F allows the operator to fill both tight and loose, non-concentric connections with ease. The strength of a Bridgit joint far exceeds the pressure point at which copper tubing will burst.

I have a follow up question. I would like to know if the sweating procedure I was used to is correct.

1. clean the outer pipe and inside coupler with emery cloth or round steel brush
2. apply flux on both
3. heat it
4. apply solder

That's pretty much what I do.

Lastly, I have always used the blue can propane. The other one is called MAPP(yellow can) if my memory recalls it properly. The guy at home depot told me not use the yellow because it's hard to work with because it's very hot. Should I use MAPP on 1" pipes or should I be fine with blue can propane?

Thanks!

Additional

Assuming you have already sweat pipes, now you turned on your water, one joint is leaking, how do you fix this issue since it's already soldered?

I've soldered 1" with the regular blue bernzo. It's about the technique. There are bigger and swirlier tips for the propane that people really like here. It is poss to use MAPP. Just shld be quicker w/ it. B4 next project, I'll def invest in a quickfire igniter. Sparkers and butane lighters are for suckas!

As far as fixing the leak ex post: Any patch rigs I've tried have not worked AT ALL around a fitting. IMHO, you should unsolder and redo the joint. It may actually be easier to cut it out.

B4 u whip out the pipe cutter, though, get a 2nd opinyun.

Once water has gotten to a joint and you discover a leak, it can not be fixed by just reheating. There are just two things you can do. Cut the fitting out, solder in a new fitting and probably add a piece of pipe and a coupling to make up the loss from cutting the fitting out, or heat the joint and remove the fitting. You can reuse the fitting, but it's a PITA to clean the old solder out. The pipe will be OK, just wipe the solder off with a rag while it's still hot. A leaking joint can be caused by moving the joint while the solder is still soft, not enough heat to flow the solder completely around the joint, or not enough solder. If you suspect a joint before you turn the water on, you can add flux and solder, but not after the water has be in the joint.

Resoldering joints

I've successfully resoldered both joints I've had fail on me in my DIY career. One was a cap on an old under-slab line where I simply didn't clean the old ratty pipe well enough before capping it. I guess I was hoping a lot of flux would cut through the oxide, but it didn't -- you've got to see bright copper everywhere you want solder to stick. I just heated it, took the cap off with a pair of slipjoint pliers, thoroughly cleaned the pipe, re-fluxed, re-heated, and placed the cap on again with the slipjoints.

The other was a 3/4" tee, don't remember the cause of the leak, probably just a dumb*ss mistake. This one taught me that you've go to be 100% sure all the water is out of the pipe, and the pipe is open to air somewhere. I thought I had drained out all the water, and by habit closed the valve when I was done draining. After applying heat for a while the joint blew apart, spraying steam, hot water, and hot solder around. After changing my pants, cleaning, re-fluxing, etc., the joint was easy to mend.

Just read Gary's post -- apparently we were both typing at the same time. I agree that you can't fix a failed joint just by reheating. You do have to disassemble, clean, and flux. However, the fact that a joint failed with water in it is no reason (IMHO) to cut it out if you can easily disassemble it.

I didn't mean to imply that you had to cut the joint out if water had gotten to it, cutting the joint out is just one of the two ways to fix a leaking joint. The other way is to disassemble. I think it depends on the individual joint, for some cutting out and replacing would be the easiest way, for others, just disassembling and redoing would be just fine.

Hi Gary,

Am I correct that as much as possible, put as many flux as I can in order to really get a tight fit and complete melted solder?

Thanks,

Neil

I'm not sure I understand exactly what you're asking. Flux does not make the joint tight, it is what makes the solder "suck" into the joint. The only joint that ever failed on me what one where I was in a hurry to finish and actually forgot to flux and was too stupid to realize that was why the solder didn't react normally when I put the solder to the joint. There is no advantage however in using more than a good coat inside the joint and on the pipe. It doesn't help when putting the pipe into the fitting, copper pipe dry fits very well. You want to be sure you heat the joint completely. I usually apply the heat to the fitting and not the pipe. I usually start heating the fitting on the side facing me, then move to the opposite side and continue heating until the solder flows on the first side. That way I know the entire joint is hot. Then I remove the heat and wipe the solder on around the entire fitting, or as much as I can reach. BTW, I sure not a pro, a pro would likely shake his head and roll his eyes if he watched me solder. But, I've only had that one failed joint, so whatever I'm doing, it works. I hope I addressed your question.

Oatey No. 95 Flux

I like the tinning fluxes such as Oatey No. 95. That little bit of tin in the flux protects the copper surfaces from oxidation and provides good wetting so the solder is drawn into the joint. You don't have to be quite as skillful to get a good joint.

You're going to get some contrarian information from me.

Just some general notes about comments made in this thread.



(1) First, unlike others, I use a Bernzomatic JTH-7.

I love this thing. It's only drawback is that it does not have an igniter. I guess that makes me a sucka.

As advertised, the flame is HOT. In fact, if you get this thing, practice on some scrap before you use it live. If you use it the way you use a pencil burner on half-inch copper then you'll turn the copper to black frangible toast.

With a MAPP pencil burner it takes me about 30 to 45 seconds to heat a 3/4 fitting. With the JTH-7 it's about ten seconds.

Another advantage is that the bottle is (should be) always upright but you can orient the burner in any direction. It's a lot easier to get into tight spaces with the JTH-7.

Call me crazy but I swear that the propane lasts a LOT longer, as well.



(2) The reason to heat joints and not pipe is that, duh!, metal expands when heated. If you heat the pipe and not the joint then you're making the pipe expand while the joint stays relatively cool. That makes it hard for the solder to be sucked into the area between the pipe and the joint. If you remember this, then it is always easy to figure out what needs to be heated on, say, a street tee.


(3) I've had success (about 40%) reheating a leaky fitting if I can drain the water out of the pipe. Using the JTH-7 I manage to get the interior of the pipe to dry.

If, OTOH, the pipe is filled with even a little bit of water you'll never get the leak to stop unless the water is completely drained out.


(4) I use a lot of flux. As I read somewhere: "Flux is your friend." As another poster noted, putting too much on won't help ... but it won't hurt, either. It also makes it easier to see whether you've fluxed the joint.

Always wondered???

I have always wondered exactly what majic FLUX did

to make two metals weld to one another???

I have used it for years and have never knew exactly how it works....




Actually....Flux does not make the solder suck into th joint.......

the heat from your torch pointed at the fartherest point

away on the joint maked the sloder flow to the heat source....

anyone actually know how this really works????


their has to be a " little factnoid" out there about htis....

As the copper heats it oxidizes. The oxidation won't allow the solder to flow.

A/C guys when they are brazing line sets have to purge the lines with nitrogen to prevent oxidation because the oxidation inside the the copper pipe, if they didn't use the nitrogen, will wipe out the compressors.

Capilary action is what causes the solder to flow back.

v1rtu0s1ty, go to HD and get Oatey #95 pretinning flux this is the best flux to use in my opinion. I end up with about 1 leak every year or 2 and I normaly know it is coming.

(2) The reason to heat joints and not pipe is that, duh!, metal expands when heated. If you heat the pipe and not the joint then you're making the pipe expand while the joint stays relatively cool. That makes it hard for the solder to be sucked into the area between the pipe and the joint. If you remember this, then it is always easy to figure out what needs to be heated on, say, a street tee.

WRONG, WRONG, WRONG1 The reason to heat the fitting and not the pipe is that capillary attraction pulls the solder to the hottest part of the joint, which should be the bottom of the socket where the end of the tubing is. If expansion were a factor then heating the tubing would make the joint even tighter which would improve the solder flow, and heating the fitting would create a looser joint which would not have good solder flow.


(3) I've had success (about 40%) reheating a leaky fitting if I can drain the water out of the pipe. Using the JTH-7 I manage to get the interior of the pipe to dry.

That is a marginal cure, since once the water touches the copper, and the flux is either burned off or washes out of the joint, the copper will oxide. Therefore, since you cannot clean or flux the bad spot, you have to depend on luck for the solder to make a good seal, but you could just be closing the surface of the leak where you can see it.

(4) I use a lot of flux. As I read somewhere: "Flux is your friend." As another poster noted, putting too much on won't help ... but it won't hurt, either. It also makes it easier to see whether you've fluxed the joint

I would hope you flux the joints as you put them together so you don't have to "see whether you've fluxed the joint". More flux just means a bit more time before you evaporate it so the soldering can begin.

Thanks folks for the advice. And yes, I used Oatey solder in my previous projects however, I don't remember the number right now.

For the flux sucking the solder, I think you guys are correct. I remember I was sweating a vertical pipe in my bathroom project. How in the hell the solder will go up? Well, it just did, I don't know why. Capillary action!

Again folks, this is a very wonderful forum. I've new tips that got added to my memory.

Flux

v1rtu0s1ty said:

Hi Gary,

Am I correct that as much as possible, put as many flux as I can in order to really get a tight fit and complete melted solder?

Thanks,

Neil

Click to expand...

You only use a minimal amount of flux, read the container. Luck.

--------------------------------------------------------------------------"If you don't have the time to do it right, where will you get the time to do it over?"

toolsrme said:

(2) The reason to heat joints and not pipe is that, duh!, metal expands when heated. If you heat the pipe and not the joint then you're making the pipe expand while the joint stays relatively cool. That makes it hard for the solder to be sucked into the area between the pipe and the joint. If you remember this, then it is always easy to figure out what needs to be heated on, say, a street tee.

Click to expand...

hj said:

WRONG, WRONG, WRONG1 The reason to heat the fitting and not the pipe is that capillary attraction pulls the solder to the hottest part of the joint, which should be the bottom of the socket where the end of the tubing is. If expansion were a factor then heating the tubing would make the joint even tighter which would improve the solder flow, and heating the fitting would create a looser joint which would not have good solder flow.

Click to expand...

HJ, I am not a plumber and I deeply appreciate your patience and knowledge.

I've been doing some online research and, I must admit, that I have learned a bunch and I stand corrected on several things.

It appears that the strength of capillary action is inversely proportional to the diameter of the "hole". Thus, theoretically, a tighter fit would yeild a stronger sucking of solder.

From http://en.wikipedia.org/wiki/Capillary_action we see that the height (strength) of a capillary action is

2 x T x cos(theta)
-----
rho x g x r

where r is the radius of the tube and is, really, the only relvant variable.

r is akin to the distance between the two pieces of copper (approximately .004 inches) and is not the radius of the pipe (e.g. half or three-quarter inches).

Clearly this formula breaks down where r gets too small. Otherwise we could make a tiny hole in a glass tube and lift water an infinite distance.

Redwood trees, for instance, have limited heights (about 400 feet) because capillary action and osmosis are limited.

I have no idea how small is "too small" in a plumbing application.

Nonetheless, if you heat the pipe rather than the fitting then there will be a very tight fit and it would prevent or slow the solder. Something like trying to make the redwood taller than 400 feet.

toolsrme said:

(3) I've had success (about 40%) reheating a leaky fitting if I can drain the water out of the pipe. Using the JTH-7 I manage to get the interior of the pipe to dry.

Click to expand...

hj said:

That is a marginal cure, since once the water touches the copper, and the flux is either burned off or washes out of the joint, the copper will oxide. Therefore, since you cannot clean or flux the bad spot, you have to depend on luck for the solder to make a good seal, but you could just be closing the surface of the leak where you can see it.

Click to expand...

I should have put in the step of applying flux to the area where the fitting meets the pipe.

I've seen my licensed plumber use this trick. I have no idea why flux is needed or why the trick sometimes works.

toolsrme said:

(4) I use a lot of flux. As I read somewhere: "Flux is your friend." As another poster noted, putting too much on won't help ... but it won't hurt, either. It also makes it easier to see whether you've fluxed the joint

Click to expand...

hj said:

I would hope you flux the joints as you put them together so you don't have to "see whether you've fluxed the joint". More flux just means a bit more time before you evaporate it so the soldering can begin.

Click to expand...

After a little research I have learned that applying too much flux is bad, bad, bad.

Applying too much flux can cause corrosion. That's why you're supposed to wipe down a joint with a damp cloth: to remove excess flux. I'm going to go around my house and wipe down my joints now that I know this. It's been about 5 months since I've started doing the plumbing in this renovation. I hope I've not done a lot of permanent damage.

The point about putting on "too much" is that too much is far better than none at all.

If you work in dark places then it is sometimes hard to see and/or remember which parts have been fluxed.

In terms of flux evaporating so that the soldering can begin: The solder and flux and the copper interact. If the flux wasn't there (it evaporated) then the copper would oxidize and you'd have a bad joint.

Geez, there is so much to learn.

I apologize to everyone for my misinformation.

Lastly, in my researches I've seen the following URL: www.copper.org / copperhome / DIY / do it yourself _ soldering school . html

(Could someone tell me why it's impossible to put in a URL in this forum? Why do asterisks show up when I put in a long URL? To get to the URL you'll need to remove all the blanks. Grr.)

Anyone want to comment on whether they're right about heating the pipe and/or any other comments about their technique.