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

Reply to
T. C. Conde
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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

Reply to
Voyager

Reply to
T. C. Conde

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.

Reply to
Voyager

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

Reply to
Steve Barker DLT

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!
Reply to
PeterD

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

Reply to
PeterD

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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Reply to
dpb

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

Reply to
Steve Barker DLT

Yes, and now give faulty advice about solder. Hmmm.... :-)

Reply to
Voyager

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.

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.

Reply to
PeterD

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

Reply to
Bobk207

What size pipe, Mapp gas would heat it up.

Reply to
ransley

Pick up some flux on the solder then apply to hot joint. Thats what I do.

Reply to
Cwatters

That gets my vote.

Reply to
Cwatters

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