PROBLEM SWEATING COPPER. WHAT AM I DOIN WRONG?

I am a general contractor but it has been years since I sweated copper.
I cut the pipe with a pipe cutter tool. I clean both the pipe end (male) and the fitting (female) thoroughly. It is shiny clean. I coat both with paste flux (the brown stuff). I put the two pieces together until the pipe seats all the way into the fitting. My torch is one of these where you just push the button and the gas comes on and it lights. The flame is not a pin-point, it is pretty open. I hold it about an inch from the fitting and heat it up. I have to stay on one side of the fitting since I am blocked by things in the way. the flame is on it about 8-10 seconds. I apply solder and it melts but it doesn't go into the fitting, it just balls up and runs off without being sucked into the fitting. What am I doing wrong?
Thanx
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T. C. Conde wrote:

I had this problem when using the flux that came with my torch kit. The flux was white and I couldn't believe it was the problem, but after several joints did just as you describe, I decided to try different flux. I bought some Oatey brand which looks a little like grease. It is brownish in color, but somewhat translucent whereas the white flux that came with my torch was completely opaque and looked a little like toothpaste.
With the Oatey flux, the solder behaved just as it should and the joint sucked it in like a sponge. I suspect the flux in the torch may have been old or a bad batch or something, but it was unlike any other flux I'd seen before. I guess that alone should have made me suspicious sooner.
So bad flux is one possibility. Also, are you sure you have solid plumbing solder and not solder with rosin or acid core as used for electronics soldering?
Lastly, if you overheat a joint you will burn off the flux and oxidize the copper and then the solder will behave as you describe. I wouldn't think 8-10 seconds would do that, but if you have a MAPP torch this is possible. I wouldn't think propane would overheat that quickly. The way to avoid this is to hold the flame farther away to give the heat time to work around the fitting before the flame side gets too hot. Also, keep touching the solder to the joint every second or two as the fitting heats up. That way as soon as the solder begins to melt briskly when touched to the fitting, you know you have enough heat and can remove the torch and feed 1/2" or so of solder into the joint (for 1/2" tubing - 3/4" or so for 3/4" tubing).
And definitely remove the torch as you feed the solder as you will have plenty of heat at that point and don't need any more assuming you are feeding the solder into the joint at a point roughly opposite where you are applying the hear.
Matt
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I was just over at the Depot and looked at fluxes. One was a "tinning flux" and the other was "regular flux". The regular flux was the translucent brown stuff and the tinning flux looked like a light green toothpaste. The brown stuff is what I have been using. The solder is correct, right off the shelf next to the wire brushes and the flux. I am using propane, not MAPP gas. I am pretty close to the fitting, maybe just an inch or so. If the flux burns off, will the solder still work? Most of the instructional videos I see for sweating copper, the flame tip comes to a point. My flame tip is pretty broad. Maybe that is better in that it heats the entire area, not just at the flame tip. Any thoughts?
Tim

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T. C. Conde wrote:

I'm not a professional plumber, but I did add a bathroom to my basement last year and got to sweat a fair number of joints and also had to "T" into my main 3/4" home lines (that was a little nerve racking). I did a few practice joints and once I got the right flux it worked well.
Yes, you can definitely burn off the flux and, no, the solder won't take when that happens. If you start to see a lot of smoke, you are too hot. Again, an experienced plumber can tell when the temp is right simply by the time taken and watching the flux begin to bubble and the copper change color. Amateurs like us should use the technique of continually (every 1-2 seconds) touching the solder to the joint. It will first start to "stick" a little to the fitting and that tells you that you are ALMOST up to temp. Probably a touch or two later will cause the solder to almost instantly melt when you touch the joint and that is when you want to IMMEDIATELY remove the torch and then promptly feed in enough solder to form a small partial droplet on the low part of the joint. Wipe quickly with a damp (not wet as you don't want to shock cool the joint!) rag and you are done.
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T. C. Conde wrote: ...

...
Not a lot of difference unless you're talking of really large diameter pipe.
The thing sounds to me is you're not heating the fittings hot enough -- as someone else says, you've got to heat the fittings enough to melt the solder, not using the flame to do so.
If you haven't soldered for a while, go get a few practice fittings and practice until you get the hang of it.
Heat the fitting (not the pipe into the fitting) at the base of the fitting from the rear and touch the solder to the joint on the near side. When it gets hot enough, it will melt and flow in w/ capillary action.
--
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replying to Voyager, Kpssan wrote: Its not just you im a wood pig by trade. But work being slow and mostly working for general. Contracters. I lithely. Do every thinng just the other day. It took me 45 min just to get 2. Half inch. Lines caped. Ive done hole jobs in the past and even had a 100 dollar bet with my father. And there were 85. 90s. And unions. And not one leak. But my last 5 or 6 jobs. Ive played hell just to solder half inch. What the hell i keep having to re do them over and over again. What happened to the nocoe rod. This shit home depot has now is garbage. And it might matter what state your in. Im in cali. Pkease give me back my flux. Im going to sneak over to grandpas old house. Ill bet hes got 5 cans there. One or more in each shed ps. I found an old bottle of. Tinners fluid at my fatherin law hose. And bam i was done. But i spilled it. Messy area. And pissed
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sounds like you're using that junky lead free shit. Get some real solder from the stain glass shop and you'll be fine.
s

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On Sun, 19 Oct 2008 22:40:24 -0500, "Steve Barker DLT"

Which is not a good idea at all. There is a good reason for lead free solder.

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PeterD wrote:

Plus quality lead free solder works fine. It wets well and makes a good joint. The only time I ever had trouble with lead free was when a buddy called me. He had to get a replacement water heater so he bought a torch , solder and flux at Home Depot and asked if I could sweat the couplings because he wasn't confident in his soldering skills. The solder he bought from Home Depot wouldn't wet. I had to drive home and get some solder that I had purchased at the local real plumbing store. It took a few minutes to make perfect joints. If someone wasn't familiar with soldering they would have spent the weekend with the Home Depot stuff wondering what they were doing wrong.

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wrote:

Ouch... Most of the lead free stuff requires more heat, too, which some people don't realize. I've also found it stronger (and harder), too. I consider that a benefit. (Not that I've had either fail once properlly sweated together...)
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PeterD wrote:

Yes, I used lead-free solder and it worked just fine once I had a good quality flux. Yes, it takes a little more heat, but nothing a standard propane torch can't easily provide.
Matt
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OH? do tell...... and lets not cite that government bullshit about lead leaching into the water and getting consumed.. doesn't hold up... millions of us grew up drinking tap water from real solder sweated copper plumbed houses.
s

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Steve Barker DLT wrote:

Yes, and now give faulty advice about solder. Hmmm.... :-)
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On Mon, 20 Oct 2008 19:25:15 -0500, "Steve Barker DLT"

Agreed, I too grew up in houses with lead soldered pipes. I don't think it caused my Drain Bamage, but can't be sure. <bg>
The issue is that later, when selling the house, if the buyer finds lead solder in a house where there should not be any, the seller may (well after the fact, too) be required to set it straight. Selling a property in today's world is very complex, and leaves the seller holding the bag, so to speak, for extended periods of time.

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Since it wasn't until the 1980's that lead free began to be required .....there are a whole lot of homes in the US with lead based solder.
Lead paint was phased out in the 70's.
So what % of US homes have some lead paint & lead based solder?
yeah, lead free solder might be a good idea but I'd like to see the data showing how much personal lead loading is due to residential use of lead based solder.....
fyi only 50% of ingested lead is absorbed...90% of inhaled lead is absorbed
cheers Bob
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On Sun, 19 Oct 2008 15:54:11 -0700, "T. C. Conde"

8-10 seconds? Not nearly long enough. The pipe must get hot enough to melt the solder, not the flame. Right now you are melting the solder with the flame, but the pipes are still down-right cold!

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> 8-10 seconds? Not nearly long enough. The pipe must get hot enough to

That gets my vote.
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What size pipe, Mapp gas would heat it up.
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Pick up some flux on the solder then apply to hot joint. Thats what I do.
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