I finally did the installation I have asked a bunch of questions about. It
involved putting some Ts in the main water line.

One of the joints had a tiny leak, maybe a cup an hour. Reheating it,
needless to say, didn't help; so I pulled it apart, recleaned, refluxed and
resoldered. It is fine now. But I have some questions for future
reference.

1) If I had ignored the problem (it would have drained into the sump anyhow)
would it have been stable, or would it erode over time?
(A couple years ago a friend soldered in my new water heater and one of the
joints has a tiny leak; maybe a cup a day. I wrapped a cloth around it and
it evaporated faster than it leaked. A year later I put in a pressure
regulator and it stopped. Apparently the joint was okay at 55PSI, but
leaked at 90PSI.)

2) I have some plastic stretch tape that claims it stops leaks. If I
applied it with the water off, would it have stopped the leak; had I not
been able to take it apart? If not, would any product?

Thanks

I don't plan on doing anymore plumbing in the new future. Oh, not quite
true; I have to replace the kitchen faucet. Hmm.

"toller" wrote in message

1) If I had ignored the problem (it would have drained into the sump
anyhow) would it have been stable, or would it erode over time?
(A couple years ago a friend soldered in my new water heater and one of
the joints has a tiny leak; maybe a cup a day. I wrapped a cloth around
it and it evaporated faster than it leaked. A year later I put in a
pressure regulator and it stopped. Apparently the joint was okay at
55PSI, but leaked at 90PSI.)

2) I have some plastic stretch tape that claims it stops leaks. If I
applied it with the water off, would it have stopped the leak; had I not
been able to take it apart? If not, would any product?

One of those things you just never know about. Leaks may stop after time
because minerals build up and clog the leak, or corrosion in iron pipes.
Me, I'd not sleep at night knowing a pipe is not properly soldered and could
get worse while I'm away on vacation.

At work we had a joint not properly soldered in a 2" copper tubing. It
never leaked, but the tubing was not properly seated into the elbow. It
took about 8 years, but if finally let go one morning. Thousands of gallons
of water flowed before it could be shut off.

I'm not familiar with the tape, but I'd not trust it. OK for an emergency,
but I'd still fix the pipe properly.

Edwin Pawlowski wrote:
At work we had a joint not properly soldered in a 2" copper tubing.
It never leaked, but the tubing was not properly seated into the
elbow. It took about 8 years, but if finally let go one morning.
Thousands of gallons of water flowed before it could be shut off.


Never ignore warning signs when they are given to you.

I installed a water softener with all sweat soldered fittings.
Apparently I didn't seat one of the fittings all the way, or maybe it
was a cold solder joint. The joint never leaked, but it let go one
night and fortunately I was home to hear the water gushing out into the
garage. Had we been away on vacation, it would have flooded our home.

At work we had a joint not properly soldered in a 2" copper tubing. It
never leaked, but the tubing was not properly seated into the elbow. It
took about 8 years, but if finally let go one morning. Thousands of
gallons of water flowed before it could be shut off.

Ah, something new to worry about!
What is "not properly seated"? Only 1/4" of the way into a 3/4" deep joint?
My "system" is to make sure that all but the fringe of the 1" that I clean
is inside the joint. As long as I do that, the joint must be seated
properly; right?

I installed a water softener with all sweat soldered fittings.
Apparently I didn't seat one of the fittings all the way, or maybe it
was a cold solder joint. The joint never leaked, but it let go one
night and fortunately I was home to hear the water gushing out into the
garage. Had we been away on vacation, it would have flooded our home.

What is a cold solder joint?
If the solder melts on the pipe and flows in, it must be hot soldered; no?

toller wrote:
I installed a water softener with all sweat soldered fittings.
Apparently I didn't seat one of the fittings all the way, or maybe it
was a cold solder joint. The joint never leaked, but it let go one
night and fortunately I was home to hear the water gushing out into
the garage. Had we been away on vacation, it would have flooded our
home.
What is a cold solder joint?
If the solder melts on the pipe and flows in, it must be hot
soldered; no?

If the solder melts and flows it is hot, the problem is the pipe may not
be hot and it may not be properly bonded to the cold pipe. Watch what
happens when a drip of solder lands on a cold pipe sometime. It just forms
a ball and rolls off. That is why you heat the pipe not the solder and wick
the solder into the joint. It will not melt or wick if the pipe\fitting is
not hot.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

"Joseph Meehan" wrote in message
...
toller wrote:
I installed a water softener with all sweat soldered fittings.
Apparently I didn't seat one of the fittings all the way, or maybe it
was a cold solder joint. The joint never leaked, but it let go one
night and fortunately I was home to hear the water gushing out into
the garage. Had we been away on vacation, it would have flooded our
home.
What is a cold solder joint?
If the solder melts on the pipe and flows in, it must be hot
soldered; no?

If the solder melts and flows it is hot, the problem is the pipe may
not be hot and it may not be properly bonded to the cold pipe. Watch what
happens when a drip of solder lands on a cold pipe sometime. It just
forms a ball and rolls off. That is why you heat the pipe not the solder
and wick the solder into the joint. It will not melt or wick if the
pipe\fitting is not hot.

But if it does wick, then it is hot; right?
(That is what I meant by melting on the pipe and flowing in.)

toller wrote:
What is "not properly seated"? Only 1/4" of the way into a 3/4" deep
joint? My "system" is to make sure that all but the fringe of the 1"
that I clean is inside the joint. As long as I do that, the joint
must be seated properly; right?

You've got a good system. In my case I think the most likely cause of
the failure was a shallow joint (maybe 1/2" or so) combined with a
soldering job that was weakened by some movement while the solder was
cooling. I'm speculating here, but I think there was a partial fracture
of the solder connection and that over time (perhaps with some vibration
from the recycling of the water softener) the joint broke loose.

toller wrote:
"Joseph Meehan" wrote in message
...
toller wrote:
I installed a water softener with all sweat soldered fittings.
Apparently I didn't seat one of the fittings all the way, or maybe
it was a cold solder joint. The joint never leaked, but it let go
one night and fortunately I was home to hear the water gushing out
into the garage. Had we been away on vacation, it would have
flooded our home.
What is a cold solder joint?
If the solder melts on the pipe and flows in, it must be hot
soldered; no?

If the solder melts and flows it is hot, the problem is the pipe
may not be hot and it may not be properly bonded to the cold pipe. Watch
what happens when a drip of solder lands on a cold pipe
sometime. It just forms a ball and rolls off. That is why you heat
the pipe not the solder and wick the solder into the joint. It will
not melt or wick if the pipe\fitting is not hot.

But if it does wick, then it is hot; right?
(That is what I meant by melting on the pipe and flowing in.)

Not always, but I most of the time anyway.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

What is a cold solder joint?

A cold solder joint means that the copper is coated by the solder, but it
never actually combined with it. Usually caused by dirt/oxide on the copper
or movement during cooling.

A proper solder joint actually blends the copper and solder together into an
alloy.

toller wrote:

But if it does wick, then it is hot; right?
(That is what I meant by melting on the pipe and flowing in.)

Not always, but I most of the time anyway.


I was taught to:
1) Clean the pipe
2) Flux the pipe
3) Heat the pipe
4) Let the solder melt by contact with the opposite side of the pipe and
flow into the joint. If it wicks around and flows out the opposite side
from where it was melted, it was a good joint; assuming it did not leak
under pressure.

Are your telling me that is not always true? Is there anything else that
needs to be done, or any way to distinquish between good and bad joints?

I am not being argumentative; I just want to get it right.

Left out one vital step...clean the inside of the fitting.

If you do the above steps, it will be fine. As I noted before, it's
like the old question--"Do you know how to get to Carnegie Hall?"

But if it does wick, then it is hot; right?
(That is what I meant by melting on the pipe and flowing in.)

Not always, but I most of the time anyway.


I was taught to:
1) Clean the pipe
2) Flux the pipe
3) Heat the pipe
4) Let the solder melt by contact with the opposite side of the pipe and
flow into the joint. If it wicks around and flows out the opposite side
from where it was melted, it was a good joint; assuming it did not leak
under pressure.

Are your telling me that is not always true? Is there anything else that
needs to be done, or any way to distinquish between good and bad joints?

I am not being argumentative; I just want to get it right.

"Noozer" wrote in message
news:l1KQd.407930$Xk.394670@pd7tw3no...
What is a cold solder joint?

A cold solder joint means that the copper is coated by the solder, but it
never actually combined with it. Usually caused by dirt/oxide on the
copper
or movement during cooling.

Movement during cooling? My understanding is that the solder is either
liquid (when it can be moved) or solid (where it can't be moved). The
transformation was quick enough that movement was not an issue; at least in
small pipe not exposed to high forces. If any of the solder is solid enough
to be be damaged by movement, it has already become strong enough to prevent
that movement.

Am I misinformed?

"toller" wrote:

I installed a water softener with all sweat soldered fittings.
Apparently I didn't seat one of the fittings all the way, or maybe it
was a cold solder joint. The joint never leaked, but it let go one
night and fortunately I was home to hear the water gushing out into the
garage. Had we been away on vacation, it would have flooded our home.

What is a cold solder joint?

One where the solder has formed crystals.

If the solder melts on the pipe and flows in, it must be hot soldered; no?

No. Movement in the joint while cooling is the most common cause. The
solder doesn't setup as a single cohesive metal, but rather as crumbly
material, which looks "cold" compared to a good smooth shiny joint.

Not fully preparing the surfaces to be soldered is another cause, since
it keeps the solder from flowing everywhere.

The trick to soldering is to get a complete sheet of solder to melt and
reform at the same time, so it is solid.

toller wrote:
But if it does wick, then it is hot; right?
(That is what I meant by melting on the pipe and flowing in.)

Not always, but I most of the time anyway.


I was taught to:
1) Clean the pipe
2) Flux the pipe
3) Heat the pipe
4) Let the solder melt by contact with the opposite side of the pipe
and flow into the joint. If it wicks around and flows out the
opposite side from where it was melted, it was a good joint; assuming
it did not leak under pressure.

Are your telling me that is not always true? Is there anything else
that needs to be done, or any way to distinquish between good and bad
joints?
I am not being argumentative; I just want to get it right.

You got it right. Following those instructions it should work, but most
of us, well at least me, are not perfect and even when I think everything
has gone well, sometimes it did not (as you noted "assuming it did not leak
under pressure.") Maybe not clean enough, not quite enough heat due to
moisture in the pipe or working too fast etc. Frankly I seldom if ever have
a problem when I follow those procedures. It is not all that hard.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

toller wrote:
Movement during cooling? My understanding is that the solder is
either liquid (when it can be moved) or solid (where it can't be
moved). The transformation was quick enough that movement was not an
issue; at least in small pipe not exposed to high forces. If any of
the solder is solid enough to be be damaged by movement, it has
already become strong enough to prevent that movement.

Am I misinformed?

Yes.

In article , "toller" wrote:
But if it does wick, then it is hot; right?
(That is what I meant by melting on the pipe and flowing in.)

Not always, but I most of the time anyway.


I was taught to:
1) Clean the pipe

and the fitting

2) Flux the pipe

and the fitting

3) Heat the pipe

This is wrong: heat the *fitting*, not the pipe. The idea is that the fitting
will expand when heated, and contract as it cools, tightening the joint.

4) Let the solder melt by contact with the opposite side of the pipe and

Opposite side of the *joint*, to be precise.


--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

In article , "toller" wrote:

Movement during cooling? My understanding is that the solder is either
liquid (when it can be moved) or solid (where it can't be moved). The
transformation was quick enough that movement was not an issue; at least in
small pipe not exposed to high forces. If any of the solder is solid enough
to be be damaged by movement, it has already become strong enough to prevent
that movement.

Am I misinformed?

Yes, you are. The transition from liquid to solid is neither as rapid nor as
clear-cut as you think. Alloys generally don't have a crisp melting or
freezing point; instead, they liquefy or solidify over a range of several
degrees. There is also a range of temperatures below the melting point in
which the metal is plastic, that is, easily deformable. If a solder joint is
mechanically stressed before the solder has cooled below the plasticity
temperature range, it will be considerably weakened and may fail.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

In article ,
(Doug Miller) wrote:

In article , "toller"
wrote:
But if it does wick, then it is hot; right?
(That is what I meant by melting on the pipe and flowing in.)

Not always, but I most of the time anyway.


I was taught to:
1) Clean the pipe

and the fitting

2) Flux the pipe

and the fitting

3) Heat the pipe

This is wrong: heat the *fitting*, not the pipe. The idea is that the fitting
will expand when heated, and contract as it cools, tightening the joint.

4) Let the solder melt by contact with the opposite side of the pipe and

Opposite side of the *joint*, to be precise.

I've always heated both the fitting and the pipe, gently and evenly.
Testing the tip of solder on the junction every so often until it melts
then soldering the connection.

Should i not be heating the pipe at all? I thought it was best if both
were at temp.

--
charles

Charles Bishop wrote:
....
I've always heated both the fitting and the pipe, gently and evenly.
Testing the tip of solder on the junction every so often until it melts
then soldering the connection.

Should i not be heating the pipe at all? I thought it was best if both
were at temp.

Taught us to heat the pipe through the fitting, initially around it if
3/4" or larger to speed things up.

"Doug Miller" wrote in message
m...
In article , "toller"
wrote:
But if it does wick, then it is hot; right?
(That is what I meant by melting on the pipe and flowing in.)

Not always, but I most of the time anyway.


I was taught to:
1) Clean the pipe

and the fitting

2) Flux the pipe

and the fitting

3) Heat the pipe

This is wrong: heat the *fitting*, not the pipe. The idea is that the
fitting
will expand when heated, and contract as it cools, tightening the joint.

4) Let the solder melt by contact with the opposite side of the pipe and

Opposite side of the *joint*, to be precise.

You are absolutely correct; fortunately I just misspoke rather than
misunderstood; I meant fitting in all contexts.

Interestingly, my OP referred to the first soldering of the joint failing.
When I pulled it apart there was no solder on the top of the fitting; yet it
was bright and the scratches from the brush were still visible. The pipe on
the other hand was completely covered with solder.
All I can figure is that I didn't put enough flux on it, but even if I
didn't, shouldn't enough flux have rubbed off from pipe to have worked?
Apparently not.
Anyhow, I started using twice as much flux.

According to Charles Bishop :
3) Heat the pipe

This is wrong: heat the *fitting*, not the pipe. The idea is that the fitting
will expand when heated, and contract as it cools, tightening the joint.

4) Let the solder melt by contact with the opposite side of the pipe and

Opposite side of the *joint*, to be precise.

I've always heated both the fitting and the pipe, gently and evenly.
Testing the tip of solder on the junction every so often until it melts
then soldering the connection.

Should i not be heating the pipe at all? I thought it was best if both
were at temp.

If you want to be perfectly anal about it, the best way is to heat
the fitting, and then apply solder to the _pipe_, on the other side of the
joint, and not touch the solder to the edge of the fitting until it starts
to flow against the pipe.

What this does is force you to be applying solder against the coolest
part of the joint. Once _that_ is up to temperature, you're guaranteed
that the rest of the joint is up to temperature.

It matters more to pros, because they're often using acetylene or MAP
torches, which heat the joint much faster than the gentle roasting of
a propane torch, and temperature differences can be rather high.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

"Doug Miller" wrote in message
...
In article , "toller"
wrote:

Movement during cooling? My understanding is that the solder is either
liquid (when it can be moved) or solid (where it can't be moved). The
transformation was quick enough that movement was not an issue; at least
in
small pipe not exposed to high forces. If any of the solder is solid
enough
to be be damaged by movement, it has already become strong enough to
prevent
that movement.

Am I misinformed?

Yes, you are. The transition from liquid to solid is neither as rapid nor
as
clear-cut as you think. Alloys generally don't have a crisp melting or
freezing point; instead, they liquefy or solidify over a range of several
degrees. There is also a range of temperatures below the melting point in
which the metal is plastic, that is, easily deformable. If a solder joint
is
mechanically stressed before the solder has cooled below the plasticity
temperature range, it will be considerably weakened and may fail.


We talking seconds or minutes?
I don't think I have ever moved a pipe after soldering, but I have turned
the water on a few minutes afterwards. Event hen, since there was a faucet
open downstream, there wouldn't have been much force on the joint.

Speaking of which, if the water pressure is 60PSI, does that mean the
maximum pressure on the joint is 22 pounds? Would there be less with taps
open?

toller wrote:
"Doug Miller" wrote in message
m...
In article , "toller"
wrote:
But if it does wick, then it is hot; right?
(That is what I meant by melting on the pipe and flowing in.)

Not always, but I most of the time anyway.


I was taught to:
1) Clean the pipe

and the fitting

2) Flux the pipe

and the fitting

3) Heat the pipe

This is wrong: heat the *fitting*, not the pipe. The idea is that the
fitting
will expand when heated, and contract as it cools, tightening the
joint.
4) Let the solder melt by contact with the opposite side of the
pipe and

Opposite side of the *joint*, to be precise.

You are absolutely correct; fortunately I just misspoke rather than
misunderstood; I meant fitting in all contexts.

Interestingly, my OP referred to the first soldering of the joint
failing. When I pulled it apart there was no solder on the top of the
fitting; yet it was bright and the scratches from the brush were
still visible. The pipe on the other hand was completely covered
with solder. All I can figure is that I didn't put enough flux on it, but
even if I
didn't, shouldn't enough flux have rubbed off from pipe to have
worked? Apparently not.
Anyhow, I started using twice as much flux.

I can remember once when I put in a water heater using CPVC and turned
the water back on. Everything was looking good when a little drop formed
under a fitting. I touched it and it gave way. I had totally missed that
fitting, no cleaner no solvent. :-)

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

toller wrote:
We talking seconds or minutes?
Seconds. 1 to 5, maybe.

Speaking of which, if the water pressure is 60PSI, does that mean the
maximum pressure on the joint is 22 pounds?

Nope, 60 psi.

Would there be less with taps open?

Of course.

"Doug Miller" wrote in message
...
In article , "toller"
wrote:

Movement during cooling? My understanding is that the solder is either
liquid (when it can be moved) or solid (where it can't be moved). The
transformation was quick enough that movement was not an issue; at least
in
small pipe not exposed to high forces. If any of the solder is solid
enough
to be be damaged by movement, it has already become strong enough to
prevent
that movement.

Am I misinformed?

Yes, you are. The transition from liquid to solid is neither as rapid nor
as
clear-cut as you think. Alloys generally don't have a crisp melting or
freezing point; instead, they liquefy or solidify over a range of several
degrees. There is also a range of temperatures below the melting point in
which the metal is plastic, that is, easily deformable. If a solder joint
is
mechanically stressed before the solder has cooled below the plasticity
temperature range, it will be considerably weakened and may fail.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

63/37 solder solidifies almost instantly.

"Travis Jordan" wrote in message
...
toller wrote:
We talking seconds or minutes?
Seconds. 1 to 5, maybe.

Speaking of which, if the water pressure is 60PSI, does that mean the
maximum pressure on the joint is 22 pounds?

Nope, 60 psi.

I have to be more careful with my wording. Of course the pressure is 60psi;
I meant "force". There is less than a half inch cross section (3/4" pipe),
so that comes to about 22 pounds.
Or does it not work that way?
Probably involves hydrodynamics or something.

In article , tt (Charles Bishop) wrote:


I've always heated both the fitting and the pipe, gently and evenly.
Testing the tip of solder on the junction every so often until it melts
then soldering the connection.

Should i not be heating the pipe at all? I thought it was best if both
were at temp.

You should apply heat only to the fitting; the pipe will get hot enough
anyway through contact with the fitting. If the pipe is heated directly, it
can expand far enough to prevent sufficient solder from flowing into the
joint, producing a weak joint.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

In article , "Joseph Meehan" wrote:

I can remember once when I put in a water heater using CPVC and turned
the water back on. Everything was looking good when a little drop formed
under a fitting. I touched it and it gave way. I had totally missed that
fitting, no cleaner no solvent. :-)

Could be worse... this guy I used to know re-plumbed his kitchen, and didn't
even *know* he was supposed to cement the pipes into the fittings. I heard the
story from his wife; I guess there was quite a fountain in the crawlspace when
he turned the pressure back on...

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

In article , "toller" wrote:

"Doug Miller" wrote in message
m...
In article , "toller"
wrote:

Movement during cooling? My understanding is that the solder is either
liquid (when it can be moved) or solid (where it can't be moved). The
transformation was quick enough that movement was not an issue; at least
in
small pipe not exposed to high forces. If any of the solder is solid
enough
to be be damaged by movement, it has already become strong enough to
prevent
that movement.

Am I misinformed?

Yes, you are. The transition from liquid to solid is neither as rapid nor
as
clear-cut as you think. Alloys generally don't have a crisp melting or
freezing point; instead, they liquefy or solidify over a range of several
degrees. There is also a range of temperatures below the melting point in
which the metal is plastic, that is, easily deformable. If a solder joint
is
mechanically stressed before the solder has cooled below the plasticity
temperature range, it will be considerably weakened and may fail.


We talking seconds or minutes?

Not sure... my gut feeling is that it's on the order of twenty or thirty
seconds, but I've never timed it. Certainly it's not "minutes", but I don't
want to tell you "seconds" and have you think that I mean as little as two or
three seconds. I'm sure it's more than that.

I don't think I have ever moved a pipe after soldering, but I have turned
the water on a few minutes afterwards. Event hen, since there was a faucet
open downstream, there wouldn't have been much force on the joint.

You're treading on thin ice IMO. I always allow joints to cool to room
temperature before pressurizing them. Allowing water into the joint too soon
will produce *very* rapid cooling, which certainly introduces unnecessary
mechanical stress on the joint.

Speaking of which, if the water pressure is 60PSI, does that mean the
maximum pressure on the joint is 22 pounds?

Not unless you're talking about some pretty small pipes.

Nominal 3/4" pipe is a bit under 7/8" actual diameter, and hence approximately
2.75" in circumference. The joint is about 3/4" deep, so the total area of the
joint is around two square inches. Thus the total force exerted on the area of
the joint, at 60 psi, would be around 120 pounds.

Similar calculation for nominal 1/2" pipe gives approximately 50 pounds total
force if I did the math right.

Would there be less with taps open?

Certainly.



--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

In article , "toller" wrote:

"Travis Jordan" wrote in message
.. .
toller wrote:
We talking seconds or minutes?
Seconds. 1 to 5, maybe.

Speaking of which, if the water pressure is 60PSI, does that mean the
maximum pressure on the joint is 22 pounds?

Nope, 60 psi.

I have to be more careful with my wording. Of course the pressure is 60psi;
I meant "force". There is less than a half inch cross section (3/4" pipe),
so that comes to about 22 pounds.

How do you figure that? The area of a 3/4" diameter circle is 0.44 square
inches. 60 * 0.44 = 26.4.

Or does it not work that way?

Sure, but the area of the joint is, well, it's the area of the joint. It's not
the same as the cross-sectional area of the pipe.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

toller wrote:

2) I have some plastic stretch tape that claims it stops leaks. If I
applied it with the water off, would it have stopped the leak; had I
not been able to take it apart? If not, would any product?

If you are referring to very thin teflon tape (which has no adhesive), then it's for sealing threaded joints.
Unscrew, apply to the thread then screw up the connection. In the old days, plumbers used sisal for the same
purpose.

"Tom N" wrote in message
...
toller wrote:

2) I have some plastic stretch tape that claims it stops leaks. If I
applied it with the water off, would it have stopped the leak; had I
not been able to take it apart? If not, would any product?

If you are referring to very thin teflon tape (which has no adhesive),
then it's for sealing threaded joints.
Unscrew, apply to the thread then screw up the connection. In the old
days, plumbers used sisal for the same
purpose.

It is black, slightly adhesive, tape called SealWrap Repair tape. It feels
similar to electrical tape, except that you stretch it out as you apply it.
I have had it sitting in my basement for 2 years without using it, so
yesterday I decided to see what it would do. I taped up a 1.5" PVC pipe
joint. After 15 minutes, with one end clamped in a vice, it was very
difficult to pull apart. Not as strong as gluing it, but it would certainly
hold a drain together.
I don't know what it would do on a supply line leak. Maybe I will try that
next.

Doug Miller wrote:
....
Speaking of which, if the water pressure is 60PSI, does that mean the
maximum pressure on the joint is 22 pounds?

Nope, 60 psi.

I have to be more careful with my wording. Of course the pressure is 60psi;
I meant "force". There is less than a half inch cross section (3/4" pipe),
so that comes to about 22 pounds.

How do you figure that? The area of a 3/4" diameter circle is 0.44 square
inches. 60 * 0.44 = 26.4.

Or does it not work that way?

Sure, but the area of the joint is, well, it's the area of the joint. It's not
the same as the cross-sectional area of the pipe.

Correct...it's the "wetted perimeter"...there's a total of (pi*id) in^2
of surface area on the inner wall of the pipe/unit length.

However, as you note there is no portion of the solder joint that is
directly exposed to the water except that which fills the annulus
between the OD of the pipe and the ID of the fitting...that's a much
smaller area.

Doug Miller wrote:
....
Not unless you're talking about some pretty small pipes.

Nominal 3/4" pipe is a bit under 7/8" actual diameter, and hence approximately
2.75" in circumference. The joint is about 3/4" deep, so the total area of the
joint is around two square inches. Thus the total force exerted on the area of
the joint, at 60 psi, would be around 120 pounds.
....

But the solder joint only "sees" the area of the annular section between
the OD of the pipe and the ID of the fitting which I think is what
toller's concerned about...

I don't know what design tolerances are but they're certainly no more
than roughly 1/32" so for a 3/4" pipe you're talking an area of roughly
7/8"*pi*1/32" 0.1 in^2.

"Duane Bozarth" wrote in message
...
Doug Miller wrote:
...
Not unless you're talking about some pretty small pipes.

Nominal 3/4" pipe is a bit under 7/8" actual diameter, and hence
approximately
2.75" in circumference. The joint is about 3/4" deep, so the total area
of the
joint is around two square inches. Thus the total force exerted on the
area of
the joint, at 60 psi, would be around 120 pounds.
...

But the solder joint only "sees" the area of the annular section between
the OD of the pipe and the ID of the fitting which I think is what
toller's concerned about...

I don't know what design tolerances are but they're certainly no more
than roughly 1/32" so for a 3/4" pipe you're talking an area of roughly
7/8"*pi*1/32" 0.1 in^2.

It seems to me that the outward force is irrelevant to the joints failure.
The force that will cause the joint to fail is perpendicular to the joint.
Obviously that force is proportional to the pressure. My sense is that it
is, as I said before, that it is PSI*( joint cross section area); but my
engineering degree has 30 years of dust on it.

On Thu, 17 Feb 2005 08:58:13 -0600, Duane Bozarth
wrote:

Doug Miller wrote:
...
Not unless you're talking about some pretty small pipes.

Nominal 3/4" pipe is a bit under 7/8" actual diameter, and hence approximately
2.75" in circumference. The joint is about 3/4" deep, so the total area of the
joint is around two square inches. Thus the total force exerted on the area of
the joint, at 60 psi, would be around 120 pounds.
...

Depends on which force(s) you're talking about.
The force that is exerted in trying to force the
joint apart endwise (pulling the pipe out of
the fitting) is proportional to the cross-sectional
area of the pipe. Since the pipe is probably
not actually all the way home against the stops,
you'd use the OD of the pipe to calculate this.

The force that's trying to squeeze the solder out
from between the pipe and the fitting is proportional
to the area of the seam between the pipe and fitting,
wich you would calculate by taking the difference
between the OD of the pipe, and the ID of the
fitting.

The "bursting force" applied to the part of the pipe
that's inside the fitting, would be found by multiplying
the ID of the pipe by Pii and again by the length inserted,
but that last force is pretty much irrelevent, since it's
resisted by the pipe-metal itself.

Is all cases, the pressure exerted by the system when
everything is still will be dwarfed by the pressures exerted
when someone shuts off a fixture somewhere.
(This is one of the few things about which a normal
gate valve is better than a ball valve. Gate valves
close more slowly.)

--Goedjn

Doug Miller wrote:
In article , tt (Charles Bishop) wrote:


I've always heated both the fitting and the pipe, gently and evenly.
Testing the tip of solder on the junction every so often until it melts
then soldering the connection.

Should i not be heating the pipe at all? I thought it was best if both
were at temp.


You should apply heat only to the fitting; the pipe will get hot enough
anyway through contact with the fitting. If the pipe is heated directly, it
can expand far enough to prevent sufficient solder from flowing into the
joint, producing a weak joint.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

A few opinions on sweating pipes, I do this for a living. Even went to
school for it.
Use the hottest torch you can get, my favorite for soft solder is a
Turbo Torch using Mapp gas. Then use the hottest part of the flame, in
this case about 1/2" past the inner cone. You will do less damage to the
surrounding area with a hot torch. Get in there get it hot and get out.
Clean everything including the solder. Apply a paste flux sparingly to
the outside of the pipe, first 1/8" inside of the fitting, and a little
on the solder. Secure the pipe to avoid movement.
Rule of thumb, with normal 1/8" solder you will use the same length of
solder as the circumference of the pipe. Make a bend in the solder at
that point.
Protect any heat sensitive parts with wet rags. Preheat the pipe
concentrating at edge of the fitting and keep the torch moving. When the
pipe is hot enough to melt the solder move the torch on too the
fitting. That is the big secret, solder will flow towards the heat. This
is especially important on vertical joints.
Practice on some scrap pipe, with a little technique you can literally
pump solder uphill through the joint and into the inside of the pipe.
I test all my soft joints at 200 psi and my silver (solder) braze ones
at 400 psi, I don't have leaks.
Dave

According to Duane Bozarth :
Doug Miller wrote:
...
Not unless you're talking about some pretty small pipes.

Nominal 3/4" pipe is a bit under 7/8" actual diameter, and hence approximately
2.75" in circumference. The joint is about 3/4" deep, so the total area of the
joint is around two square inches. Thus the total force exerted on the area of
the joint, at 60 psi, would be around 120 pounds.

But the solder joint only "sees" the area of the annular section between
the OD of the pipe and the ID of the fitting which I think is what
toller's concerned about...

I don't know what design tolerances are but they're certainly no more
than roughly 1/32" so for a 3/4" pipe you're talking an area of roughly
7/8"*pi*1/32" 0.1 in^2.

Doug's referring to total outward pressure on that "section" of the plumbing
(where the fitting and pipe overlap). Since the pipe and fitting are theoretically
bonded by solder, that's the total pressure that the combined assembly is being
expected to withstand.

Given that standard copper pipe is rated for 200PSI, and the fitting will
add more than 200PSI to that, I don't think toller needs to worry about the
plumbing bursting ;-)

That said, since we were actually talking about inadequately seated fittings
and "bursting apart", this is the wrong number for Toller. For toller, you
have to compute the force being exerted longitudinally, and compare that
to the shear strength of the existing solder bond he managed to establish.

The longitudinal force is simply the cross-sectional area of the pipe multiplied
by the PSI. The shear strength of the solder joint is a shear strength of solder
(whatever that is, in PSI) multiplied by the solder-wetted area (whatever that is).

[Counting dry-solder areas as zero shear strength ;-)]

If the shear strength is less than the longitudinal force, then the joint pops apart.

Further, during water hammer, the longitudinal force can jump _substantially_. So,
the solder-wetted area may be high enough for static 60PSI, but when you have several
hundred PSI of water hammer pressure spike, you need more wetted area than 60PSI
would suggest.

Clearly, there's lots of safety-margin in standard plumbing. Indeed, I believe
that a regular endcap would rupture before a properly done full depth solder joint
failed.

But if you only managed an average of 1/32" worth of solder round the circumference
of the joint, 60PSI is probably enough to blow the joint apart.

[Remembers, not fondly, discovering that the main ABS waste stack on our two story
house was seated perhaps only 1/16" of an inch into the elbow under the basement
slab. Top end was rigidly held "up" by the house framing. After a few years,
building expansion/contraction finally popped the joint apart. **** fountain.
I hate that.]
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.

toller wrote:
....
It seems to me that the outward force is irrelevant to the joints failure.
The force that will cause the joint to fail is perpendicular to the joint.
Obviously that force is proportional to the pressure. My sense is that it
is, as I said before, that it is PSI*( joint cross section area); but my
engineering degree has 30 years of dust on it.

I thought you were concerned w/ the pressure on the area of solder...

The (static) mechanical force to cause a pipe section lengthwise out the
end of the joint is the pressure times the cross-sectional area of
whatever the end termination happens to be. Radially exerted forces
aren't significant for the joint failure.

Dynamic forces will far exceed static and the strength of a good solder
joint will withstand significantly above the static pressure before
failing. In fact, I would expect the first point of failure to be the
tubing seams or other fittings long before actual joint failure.