Hose bib install - failure of sweated joint

I was able to sweat an extension pipe to end of bib w/o problem. Installed in wall. Screwed male copper fitting into end of valve, fluxed, slid extension pipe into fitting, sweated, had a leak.
Re did everything, no leak, caulked outside. A day later it started dripping. Next afternoon, top of wall was wet. Turned valve off, joint broke loose. Re-did eveything again w/very similar results. Im thinking the joint isn't hot enough to suck in the solder. How hot can I get it w/o ruining the ball valve? Is there something im missing? Thanks inadvance, .....don t. .....

When I'm using a propane torch near wood framing like in a joist channel there are two things I do to prevent fires. Sometimes I spray down all flammable surfaces with water from a spray bottle before I light the torch. The other thing is to put something uninflammable on the far side of the flame. In my plumbing tool box I keep several pieces of asbestos house siding with one or more holes at the edges so that I can tack them in place. In a tight situation where a lot of heat is going to be needed I'll often do both. I wouldn't bother to look for asbestos---sheet metal would be adequate to keep the flame off the wood and wouldn't transmit enough heat to be dangerous in the time it takes to make the solder flow. Spray down the wood afterwards, though.

To protect valves and previously soldered joints near a new connection in process I will wrap a wet rag around what I don't want overheated. If there is any theoretical basis for this not working, it will have to make an exception for my 25 year success rate doing it.

Don, you shouldn't be having a 50% failure rate on soldered joints in the field or anywhere else. I think there's some fundamental element that's bad with your supplies or your technique. I don't mean this in an insulting way. For years I used to consider a sweat plumbing job to be a hit and miss operation. I'd do the plumbing, turn on the water, mark the leaks, turn off the water, and repeat the process until there were no leaks. At some point I came to realize that I had to be doing something wrong. Plumbers typically expect NO leaks on a house sized job. I took the time to reevaluate what I was doing, and to make sure the flux and the solder I used was what an experienced plumber would use. Then I did a lot of practice on mock-ups (you won't want to do this more than once since you have to go to the trouble of pressurizing it.) Now my failure rate is near zero, complex joints and difficult locations included. Just because plumbing is only an occasional job for you doesn't do anything to reduce the frustration you feel when a joint fails.

All the best, Stan

Ok, 50% failure maybe exaggerated but so far im 0 for 3 on this project (grin).

"supplies"...I had been using flux my FIL used. He died 20 years ago. For the current project, I bought new from the local True Value.

"or your technique"...probably the main issue. I have melted valves in my younger days. Prolly use to much caution now, not enough heat, failure rates go up. Actually, I've got a leaky tub faucet that s/b replaced.

"insulting way"...I found nothing insulting w/your reply. Thats why I come to YT, and have for years. I read alot and learn, post where I have experience. Thanks again, Have fun.....don t. .....

People with excellent advice all seem to be early risers on this one. Everything that has been said is relevant. Here are the absolutely crucial points, according to my experience.

1. Completely clean, both mechanically and chemically. Every bit of the mating surfaces has to be cleaned and fluxed.

2. Good materials and equipment. Right flux, right solder.

3. Enough heat. For joints that are especially difficult to have to redo, or where a lot of mass is involved, I also use two torches---on opposite sides of the joint. If you do this, have a place to set the torch that's in the hand you're going to pick up the solder with without having to take your eyes from the joint. Ditto with picking up the solder. I've had consistent bad luck with the cylinders of MAPP gas I've bought, but if you can get around this problem MAPP is a way to get more heat on the joint.

4. Correct application. Apply the solder to the side not being heated. If it doesn't flow into the joint immediately, don't hold it against the copper waiting for it to do so. When it's running into the joint, continue to feed it until you see the beginning of a drip at the bottom of the joint. This is overkill of the better safe than sorry variety.

5. Don't make bad connections and pray that they will work. If it acts funny while you're trying to get it soldered, hoping for the best is bad policy. Take the joint apart and prepare it again. Over all it's much less frustrating to do the prep again than to take apart a partly soldered joint and do even more work to get it ready a second time.

Best of luck. I feel for you on this one, brother.

Stan

1. Get it clean. I use special brushes made to clean the pipes and fittings. They cost a few bucks at Home Depot; well worth it. If there's much corrosion I break out the emery cloth. If there is any paint on the pipe, you must get it absolutely clean for several inches from the joint; any paint near the joint will contaminate it.

2. Don't skimp on flux. Flux both the pipe and fitting. I like to flux an extra 1/2 inch or so of the pipe so I can see that I got a good joint.

3. Get it dry. This is the most important part. Do whatever it takes to get as much water as possible out of the pipe. Usually you can find a way to drain the pipe, but sometimes you'll have to blow water back through the system. A lot of times on a horizontal pipe, there's just no way to avoid water draining toward the joint. In those cases, I get a second torch and use one to heat the pipe a few inches upstream of the joint.

4. Use enough torch. Most propane torches are marginally hot enough the do the job. I like to have two torches: One standard and one "Turbo-Torch". The Turbo Torch is a little too much for confined spots, but works great anywhere you have room for a big flame. For really tough stuff I have a Smith "C" tip for my oxyacetylene torch that can put an incredible amount of heat on a joint without heating the surrounding material. I only break it out for the very difficult jobs.

The way I solder valves is to get the pipe good and hot before I start putting heat on the valve. That way I only have to get the valve barely hot enough to melt the solder.

When sweating a joint, be sure the section you are working on is vented. If you don't, as you heat, the pressure will build inside and push the solder out of the joint. When heating, apply solder to the opposite side of the joint that the torch is on. If the wire solder "sticks" and doesn't flow readily, heat a bit longer before re-applying the solder.

Ball valves will take quite a bit of heat. I always close them when soldering, (still remember the venting rule!), but it may not really matter.

Good luck,
Scott