Newbie sweating pipes

Andrew21 · May 19, 2007

Hey all,

I have a question to ask you. I think I'm doing this right because one side is right. I had these 2 'garden' type valves in the kitchen and I had to get rid of them, putting caps on them while I redo my kitchen. I used the pipe cutter on both and did the hot side first. The cap went on nicely using the torch and solder. The cold side is where I'm having trouble. Before I start to sweat this side, I blew into the pipe and heard water coming up. So I did that till no more water came out..but you can still hear something wanting to come up but it was dry. Putting the cap on with the flux, heated the pipe/cap, and then put the solder on the ends and watched it suck in. Waited 5 min, then turned on the water, guess what? It was springing a small pin hole leak. Waited 10 min, heated the cap, took it off and cooled down the pipe/cap. Had the wire brush, cleaned everything off and tried again..i'm still leaking! Is there water coming up that I don't know of? I'm sitting here blowing in till no water comes up. I even tried to heat the pipe up with another cap to see if steam comes out but nothing. Should I try to stuff bread in this pipe? Sorry for the long rant..

Andy

Jimbo · May 19, 2007

If there is no opening somewhere on that line, steam pressure can build up as the water in the pipe boils. That will blow out a pinhole. You could try a shop vac to remove more water, and if necessary, why not try the bread crumbs. Actually, today you can also buy some gelatin balls made specifically for this purpose. They disolve eventually in the water, faster then heated, and can be flushed out when the time comes.

Sponsor · 2022-01-29T12:20:58-0800

Kordts · May 19, 2007

Don't use a wire brush, use gritcloth. Open another faucet and blow thru it, that should get enough water out so it won't make steam. Use a new cleaned cap as well.

Andrew21 · May 19, 2007

kordts said:
Don't use a wire brush, use gritcloth. Open another faucet and blow thru it, that should get enough water out so it won't make steam. Use a new cleaned cap as well.

I'm using the sandpaper thing. Does the job well. I did open up other faucets. I'll do what Jimbo says, use the shopvac. Dad says to try to 'tilt' the pipe up so the water keeps from coming up. I'll let you know what comes about. Thanks guys!

Andy

Andrew21 · May 23, 2007

I also heard that if you torch the copper pipes too long they will not be able to 'hold' the solder. Is that true? About how long should I hold the torch to the line/cap? Till the flux starts to heat up, then put the solder on?

Prashster · May 24, 2007

Heating the pipe too long will burn off the flux. Without flux, the pipe will quickly oxidize when torched. This will prevent solder from bonding.

That's usually not the problem; you gotta heat pretty aggressively to burn off all flux. If you did the cold side right, I doubt yr overheating.

If you had other faucets open, my nonpro instinct is that you wouldn't build enough pressure to blow a leak in yr joint. If water was actually coming up to the joint, you probably wouldn't get ANY solder to suck in; it'd just bead and break at the joint.

For me, failed joints are almost always bkz of improper cleaning. You gotta sand that joint till it shines like new. That blue sandpaper (emory) works for me.

You might try cutting yr pipe back another 1/2 " in case it's slightly out of round.

Sure you know this, but to solder properly, joints gotta be absolutely cleaned, fluxed, and perfectly round and snugly fit.

hj · May 24, 2007

leak

The air expanding from the heat will be enough to cause a pinhole leak. After you solder the joint, continue feeding the solder around the joint until it cools, that way the air will suck the solder in as it cools and contracts.

paul housedok · May 24, 2007

soldering

What I always do when I have water in the line which makes solding difficult is to open up a faucet downstream and put my air compressor nozzle up to the pipe and blow the water out of the pipe.----works every time!

Andrew21 · May 24, 2007

prashster said:
Heating the pipe too long will burn off the flux. Without flux, the pipe will quickly oxidize when torched. This will prevent solder from bonding.

That's usually not the problem; you gotta heat pretty aggressively to burn off all flux. If you did the cold side right, I doubt yr overheating.

If you had other faucets open, my nonpro instinct is that you wouldn't build enough pressure to blow a leak in yr joint. If water was actually coming up to the joint, you probably wouldn't get ANY solder to suck in; it'd just bead and break at the joint.

For me, failed joints are almost always bkz of improper cleaning. You gotta sand that joint till it shines like new. That blue sandpaper (emory) works for me.

You might try cutting yr pipe back another 1/2 " in case it's slightly out of round.

Sure you know this, but to solder properly, joints gotta be absolutely cleaned, fluxed, and perfectly round and snugly fit.

Prashter,
Thank you. Might I forget to add in one detail. I got a kit from Home Depot that comes with the torch, flux, and solder. I purchased the emory paper also (blue sandpaper) and sanded the pipe end till it shined new. I did the same for the cap. I might take your approach and cut the pipe 1/2 and see what happens. When I solder this side, after I pull the flame out, I keep putting the solder around the joint and it sucks it in till it cools. I'll keep you posted.

Andy

Andrew21 · May 24, 2007

hj said:
The air expanding from the heat will be enough to cause a pinhole leak. After you solder the joint, continue feeding the solder around the joint until it cools, that way the air will suck the solder in as it cools and contracts.

HJ,
Thank you. I am doing that till the solder stops melting/sucking in. Don't know.. I'll try tomorrow.

Andy

Andrew21 · May 24, 2007

Rancher said:
What kind of flux are you using? If you use Oatley self tinning flux, almost anyone can solder.

Rancher

Rancher,
The flux that comes with the solder kit from home depot. Looks like white paste/vaseline.

Andy

Andrew21 · May 24, 2007

paul housedok said:
What I always do when I have water in the line which makes solding difficult is to open up a faucet downstream and put my air compressor nozzle up to the pipe and blow the water out of the pipe.----works every time!

I'll try that. I totally forgot I had a compressor in the next room! DOH! We'll see what happens. Thank you all again.

Andy

Jadnashua · May 24, 2007

You normally don't need to continuously add solder; once you see it has totally been sucked into the joint all the way around, normally that is enough. Having water and eventually steam can be problematic, though. Remember to move the torch when heating the fitting, too...especially on bigger, heavier joints, you can get one side hotter than you want before the other side gets hot enough. It conducts heat pretty well, but it doesn't hurt to even out the stresses.

Dunbar Plumbing · May 24, 2007

1/2" fitting = 1/2" of solder for each socket....as a gauge...

Follows the size of the pipe.

Andrew21 · May 24, 2007

jadnashua said:
You normally don't need to continuously add solder; once you see it has totally been sucked into the joint all the way around, normally that is enough. Having water and eventually steam can be problematic, though. Remember to move the torch when heating the fitting, too...especially on bigger, heavier joints, you can get one side hotter than you want before the other side gets hot enough. It conducts heat pretty well, but it doesn't hurt to even out the stresses.

Jadnashua,

I saw my plumber do this and he kept going till it cooled down. But If I remember when I failed at this a few times, I saw the solder 'drip' out. Was that because of water? It made little splatters on the floor.

hj · May 25, 2007

solder

I don't measure my solder. If I did, I would spend all my time with a ruler and not get anything done.

RochNY · May 25, 2007

I use Taramet Sterling solder with great results. It has the lowest melting point out there and gives us "rookies" a pro looking joint . I've had mixed results with Oatey solder.

Andrew21 · May 25, 2007

Ok I DID IT! WOOHOO!...

I had to cut about 1/2 of the pipe just for a fresh start. Also blew out the lines with a compressor.. I think my problem was that I had the torch on too long. As soon as I saw the copper pipe start to turn a different color, I moved it to the other side, placed the solder and it started to suck in. Took the heat off and moved the solder around as fast as I could. Seems liks its ok cause it looked like the other one. Let it cool turned on the water..TA DA! Woohoo.

THANK YOU ALL!

Andy

Jadnashua · May 25, 2007

Yes, you heated it too much...probably okay though. Next time, move the torch around as you are heating things to keep it a bit more even...no need, in fact you shouldn't, get it hot enough to change color.

Dunbar Plumbing · May 25, 2007

hj said:
I don't measure my solder. If I did, I would spend all my time with a ruler and not get anything done.

None of us plumbers "should" but that gauge of solder measuring works good for DIY'rs.

I told this to a homeowner once and he cut all his solder up to what looked like long-grain rice...used a small pliers and put each individual piece to each joint.

He probably would of had a heart attack if he wasted any solder.

Newbie sweating pipes

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