Sweating Pipes

[RobS]

Well, I finished the installation of my water softener today and all went reasonably well (only two trips to the hardware store). None of my sweated joints leak but only about half of them look as nice as the pros. What's the secret? I'm using a basic propane torch, cleaning well, flux and lead free solder. I suspect the torch isn't heating fast enough, but not sure. Is there a trick to knowing when the metal is hot enough for the solder?

I'm usually pretty handy but this is one of those things that just intimidates me for some reason [img]/forums/images/icons/smile.gif[/img]

[MikePA]

<font color="blue"> What's the secret? </font color>
Heat from one side then touch the solder on the opposite side. The solder will 'run' around the joint. Then use a wet rag to wipe the joint, particularly on the bottom before a solder 'drip' forms.

[Fawteen]

The "basic propane torch" doesn't get things hot enough quick enough to do a professional-looking job. MAPP gas is a bit better, but not much. Plumbers use an air/acetylene torch, which is a lot hotter and has a more concentrated flame.

Other than that clean, Clean, CLEAN! Flux is no substitute for a clean shiny joint. Any oxidized copper left on the pipe or the coupling/valve/elbow/whatever will affect the quality of the joint.

I disagree with wiping as well. Too easy to move something and get a cold solder joint.

JMHO, YMMV

[MikePA]

I've never used anything but propane and have always wiped the joint. I'm not sure what difference it makes how long it takes to get the joint hot enough to melt the solder, but am always willing to learn. If the way I do it is good enough for Rich Trethewey, it's good enough for me. [img]/forums/images/icons/smile.gif[/img]

[RobS]

<font color="blue"> good enough for Rich Trethewey, it's good enough for me
</font color>
Another one of my heros! I have suspected though, that the pros use more heat than the everyday propane torch puts out. No biggie as my project is complete, I'm always wanting to know how to do it better [img]/forums/images/icons/smile.gif[/img]

[MikePA]

On Ask This Old House tonight, Rich T gave a short history of torches for soldering. According to RT, while MAPP can be used for all fittings, it is usually used for larger fittings that require more heat.

[Mike_Dumond]

Just to add my .02. A propane torch will take two to three times as much time to reach temp, but it will do the job. Make sure you heat the fitting and not the pipe. As was said, heat from one side and feed from the other. When hot enough, the solder will wick in. Don't feed from the top if you can help it. The solder can melt and flow around but not wick in. From the side is preferred. As for wiping, it serves two purposes. One, it looks better. And two, it removes excess flux, which is corossive and will turn the pipe black.

Also, make sure there is no water in the pipe. Especially useful info on repairs. Even a little water can mess up easiest of jobs. With an acetalene, you can evaporate a little bit of water. With propane, it's almost impossible.

Oh, while I think of it, DO NOT USE 50/50 solder on potable pipes. Most places still allow it on heating systems with backflow preventers. People like to use it because of the lower melting temp. Any plumber worth his salt doesn't even carry it.

[beenthere]

I use propane, and wipe if I have the time. [img]/forums/images/icons/smile.gif[/img]

A trick a plumber taught me about the infuriating drip that cools the joint is to put a plug of white bread into the pipe before assembling and soldering. The bread will catch the drip, allow you time to solder, and then flush out (may have to take out a strainer at the outlet tap) when the water is turned on.

Have a "blanket" handy to put against a wood wall to "take the heat" and then watch and smell for burning wood when finished. Spray the area with water if in doubt. Too many house fires from slow burning wood that flares after a soldering job.

[ScottAR]

Since no one mentioned this, I'll add my $.02.
1.
Always heat the fitting as it has more thermal mass and will suck the solder in. Heating the pipe, the solder may run around the fitting but not go in far enough.
2.
Don't drip solder on you. It really hurts.
Happy soldering...

[Mike_Dumond]

I didn't mention the dripping solder on you cause it still hurts if I think of it [img]/forums/images/icons/shocked.gif[/img] [img]/forums/images/icons/grin.gif[/img]