On Sun, 12 May 2013 04:49:41 +0000 (UTC), Danny D
wrote:

Now I understand, from Vic Smith's article, that Teflon tape is a no-no;
and I understand that *lubrication* is a no no ... so it appears *all*
the tubes of sealant I bought from Home Depot are wrong.
http://www5.picturepush.com/photo/a/...g/12900978.jpg

The T plus 2 should work. It is for PVC, does have some Teflon -- BUT!

(also from the LASKO link)

"...A sealing compound must be compatible to plastics. Many brands of
pipe sealant contain oils, solvents or carriers that can damage
plastic. A proper sealant must be certified by the manufacturer to be
harmless to the fitting material and to not contaminate fluid in the
pipe.

Finally, a sealing compound must not lubricate the joint to the point
that over-tightening is encouraged. Several sealants on the market
meet all these requirements."

....
I would trust the T plus 2, just do not over tighten because it does
have some Teflon in it...

On Sun, 12 May 2013 08:41:40 +0200, nestork wrote:

Putting the thread sealant on the male threads, then wrapping them with
teflon tape is just as bad as using teflon tape only.

Actually, I put the Teflon tape on first ... and then put the gooey
stuff on. Now I know that both of those solutions was dead wrong!

In fact, it's extremely hard, it seems, to find the "right stuff"
at the home box stores that meets the three requirements:
a) PVC
b) Non lubricating
c) Sealant

Here is a large-format photo of the tubes of wrong "stuff" I bought:
http://www4.picturepush.com/photo/a/...g/12914627.jpg

* Harvey's TFE Paste, Part No. 023015 *
Front: White slow setting superior quality pipe thread compound *
Rear: Non-hardening, withstands up to 3,000 psi (gases) at temperatures
from -50F to +400F and 10,000 psi (liquids) from -50F to +400F.
Use on water, steam, natural, & LP gas, oils, fuels, & dilute acids.
Apply to clean male pipe threads on metals, PVC, CPVC, ABS,
polypropylene, and nylon.
Lubricates as it seals; will not harm seals of valves or faucets.

* Rectorseal Tplus2 Pipe Thread Sealant, Product Code No. 23710 *
Front: Seals and lubricates threaded connections on metal & plastics.
Formulated for potable water, natural gas and a wide variety of fluids
and gases.
Teeny tiny print: Meets CSA requirements working temperature range
-40F to 125F. Maximum working pressure 125 psi. For use with natural
gas and LP (vapor state only). Use on steel, galvanized steel, iron,
brass, copper, & aluminum. For pipe size up to & including 1 1/4".

On May 12, 7:15*am, Oren wrote:
On Sun, 12 May 2013 04:49:41 +0000 (UTC), Danny D
wrote:

Now I understand, from Vic Smith's article, that Teflon tape is a no-no;
and I understand that *lubrication* is a no no ... so it appears *all*
the tubes of sealant I bought from Home Depot are wrong.
http://www5.picturepush.com/photo/a/...g/12900978.jpg

The T plus 2 should work. It is for PVC, does have some Teflon -- BUT!

(also from the LASKO link)

"...A sealing compound must be compatible to plastics. Many brands of
pipe sealant contain oils, solvents or carriers that can damage
plastic. A proper sealant must be certified by the manufacturer to be
harmless to the fitting material and to not contaminate fluid in the
pipe.

Finally, a sealing compound must not lubricate the joint to the point
that over-tightening is encouraged. Several sealants on the market
meet all these requirements."

...
I would trust the T plus 2, just do not over tighten because it does
have some Teflon in it...

Bingo! +2 T plus 2 is the goop to use.

On Sun, 12 May 2013 05:29:15 -0700, wrote:

in the grand scheme of things, I'm not sure it makes a huge
difference.

I don't disagree - and - I'm a big believer in doing it any way
you want - BUT - only after knowing the right way to do it -
and not out of sheer ignorance (which was what I was doing).

Since this is alt.home.repair, I agree we should at least
discuss and know HOW to do it right.

At this point, we know that the correct way to do it is not
with Teflon tape, and certainly not with BOTH tape & sealant.

Also we know that the right way is to use a * non-lubricating *
sealant, which is actually hard to find at the big box stores.

http://www.spearsmfg.com/how_to/FG-3...06_English.pdf

This confirms a few things in the Vic Smith article.
- Teflon tape is deprecated
- Teflon tape is a lubricant
- Never use both Teflon tape and sealant paste
- Tighten 2 to 3 turns past finger tight

It looks like huckleberries are in season, as the "right stuff"
is the "Blue 75 thread sealant". I'll see if Home Depot has the
stuff in stock.

On Sun, 12 May 2013 07:01:35 -0700, Oren wrote:

Isn't the No.5 for metal pipe thread?

Yes.
I did not use that RectorSeal No. 5 stuff for my PVC.

In fact, it appears NONE of the "pipe stuff" I own is
correct for PVC; so I will try to find the Spears Blue 75
thread sealant at the irrigation supply places on Monday.
http://www.spearsmfg.com/how_to/FG-3...06_English.pdf

And, in the future, if I'm forced to use Teflon tape,
I'll use this method of wrapping the tape properly:
http://www5.picturepush.com/photo/a/...g/12914723.png

On Sun, 12 May 2013 16:57:56 +0000, Danny D wrote:

In fact, it appears NONE of the "pipe stuff" I own is
correct for PVC;

I should correct that slightly, by saying I read and
understood Oren's and DD_BobK's recommendation of the
best being the Tplus2 pipe thread sealant.

The only proscription against that stuff, based on
the Vic Smith article, was the fact it also lubricates
as it seals.

However, if I keep to the finger-tight-plus-two-turns
rule, I should be safe with the Tplus2 stuff.

I'm going to remove all the fittings, and try again.
http://www2.picturepush.com/photo/a/...g/12915445.jpg

On Sun, 12 May 2013 16:17:54 +0000 (UTC), Danny D
wrote:

It looks like huckleberries are in season, as the "right stuff"
is the "Blue 75 thread sealant". I'll see if Home Depot has the
stuff in stock.

I've been trying to get your attention... Instead of buying new right
now, use the T plus 2 sealant you have on hand. Yes it has Teflon, so
do not over tighten. It is for PVC pipe thread.

I use Teflon tape on PVC irrigation and some other places. I must
have ten partial rolls around here somewhere, if I rounded them up.

I just don not suggest tape on pool pipes, when a sealer is faster,
better at what it does and has no complaints from me.

The link from trader is a good one. Almost says the same as the LASCO
link, but in a different way :-\

On 5/12/2013 12:18 PM, Danny D wrote:
....

The only proscription against that stuff, based on
the Vic Smith article, was the fact it also lubricates
as it seals.

However, if I keep to the finger-tight-plus-two-turns
rule, I should be safe with the Tplus2 stuff.
....

I typically just use a little permatex blue silicone or the like. Yeah,
it's a little slick but just don't overdo tightening and you're fine.

Another that works fine is a white lithium; same thing as for usage. I
have even just used a little ol' gun grease when other wasn't handy and
it was.

--

On Sun, 12 May 2013 04:49:41 +0000 (UTC), Danny D
wrote:

On Sat, 11 May 2013 12:34:33 -0700, Oren wrote:

Again. Is the sealant you used intended for PVC pool pipe fittings?

I called RectorSeal while I was at Home Depot and they said to use
the red tube that I bought (and not the red jar, which was for metals).

The red tube says it's for "plastics", so that's what I used over the
Teflon tape.

Now I understand, from Vic Smith's article, that Teflon tape is a no-no;
and I understand that *lubrication* is a no no ... so it appears *all*
the tubes of sealant I bought from Home Depot are wrong.
http://www5.picturepush.com/photo/a/...g/12900978.jpg

I wonder if the local plumbing and irrigation supply places know this
stuff?
Just because the recommended red stuff works as a lubricant doesn't
mean it's not the right stuff. Virtually ANY sealant will "act as" a
lubricant.

On Sun, 12 May 2013 07:00:15 -0500, "HeyBub"
wrote:

DD_BobK wrote:

I'd use one or the other, not both.

Teflon is primarily a lubricant and is most effective on NPT
fittings. NPT fittings change their pitch so that the connected
pieces deform the pipe threads more and more making the seal.

Other types of threading do not change the thread pitch (if there is
any involved in the seal), so any imperfections are better dealth
with by a pipe sealant.

A lot incorrect information.....

1) Teflon is primarily a lubricant it is material to seal the
naturally occurring / designed in clearance between internal &
external pipe threads.


2) NPT fittings change their pitch so that the connected pieces deform
the pipe threads more and more making the seal. incorrect for
ubiquitous / normally used / everyday NPT threads.

NPT pipe threads do NOT have interference thread forms, they do not
change pitch.
If they deformed, how could new fittings be used on old pipe?

"Dry fit" pipe threads do exist & do seal based on interference but
they are seldom encountered in daily life.
I used them ~30 year on military hydraulic systems where dope & tape
were prohibited. Dry seal threads are a bitch to use, they sucked...
a major PITA. Be thankful that everyday threads are not as you
describe.

Take a look at the wikipedia article on pipe threads.


Likewise, look at the article on thread sealing tape:

"One of the defining characteristics of PTFE (Teflon) is how good it is at
defeating friction. The use of PTFE tape in tapered pipe threads performs a
lubricating function, which more easily allows the threads to be screwed
together, to the point of deformation, which is what creates the seal."

Just because it is a lubricand doesn't mean it is not also a sealer -
and vise versa. If all you need is a lubricant, just oil the threads
and see how well it seals - or grease the threads. It is a combination
product.

In article ,
Danny D wrote:
Q: Does the order of the tape & pipe sealant matter?

Starting with this:
http://www2.picturepush.com/photo/a/...g/12901000.jpg

Just wondering, if, for critical 2" PVC applications such as
pool equipment, when using *both* pipe sealant & teflon tape:
http://www5.picturepush.com/photo/a/...g/12900978.jpg

Does it matter if we put the teflon tape first:
http://www3.picturepush.com/photo/a/...g/12901031.jpg

And then the pipe sealant?
http://www1.picturepush.com/photo/a/...g/12901034.jpg

Before screwing the fitting into the housing:
http://www5.picturepush.com/photo/a/...g/12901038.jpg

Just curious:
Q: Does the order of the tape & pipe sealant matter?


It doesn't matter what order you apply them in, as long as you apply
the first properly, and NEVER apply the 2nd.


--
Often wrong, never in doubt.

Larry W. - Baltimore Maryland - lwasserm(a)sdf. lonestar. org

Since most plumbers I know still use teflon tape on plastic threads, I'd say no.

The people working the counter in plumbing wholesalers won't be plumbers. They may have gotten that job because they have some sort of plumbing related experience, but nobody is going to work for minimum wage working the counter at a plumbing wholesaler if they can make several times that wage working as a plumber for a plumbing company.

On Sun, 12 May 2013 20:42:31 +0000 (UTC),
(Larry W) wrote:

In article ,
Danny D wrote:
Q: Does the order of the tape & pipe sealant matter?

Starting with this:
http://www2.picturepush.com/photo/a/...g/12901000.jpg

Just wondering, if, for critical 2" PVC applications such as
pool equipment, when using *both* pipe sealant & teflon tape:
http://www5.picturepush.com/photo/a/...g/12900978.jpg

Does it matter if we put the teflon tape first:
http://www3.picturepush.com/photo/a/...g/12901031.jpg

And then the pipe sealant?
http://www1.picturepush.com/photo/a/...g/12901034.jpg

Before screwing the fitting into the housing:
http://www5.picturepush.com/photo/a/...g/12901038.jpg

Just curious:
Q: Does the order of the tape & pipe sealant matter?


It doesn't matter what order you apply them in, as long as you apply
the first properly, and NEVER apply the 2nd.

You still have to apply the correct one first.

On Sun, 12 May 2013 17:18:09 +0000 (UTC), Danny D
wrote:


The only proscription against that stuff, based on
the Vic Smith article, was the fact it also lubricates
as it seals.


Please quit saying that's "my article." I didn't write that, I just
cited it. I have no experience at all with threaded plastic pipe.
And I'm not buying all this emphasis on "lubricate vs non-lubricate."
As long as it's compatible with the plastic, seals the threads, and
doesn't harden up, it should work.
"Overtightening" because threads are lubed makes no sense to me.
One guy's "feel" for tight isn't the same as another's. You use a
different length wrench, the feel changes.
Likewise, these guys are saying stuff like "2 turns past
finger-tight." That fine if there's no burrs on the threads, the
threads are consistently formed, and everybody has the same fingers.
That's not realistic. What's more realistic is a consistent taper and
consistent thread count.
You want to look at how many threads should still be exposed for a
good fit, and tighten to there. lube or no lube. I can see that with
galvanized and know when the male is inserted far enough .
The force used to get there can vary depending on the thread
condition, but threads exposed is the best indication of what force
the taper is putting on the female, and when to stop cranking down.
Anyway, that's how I'd approach tightening plastic too.
But until I did it, it's still a guess to me.

It does to me.

The less force needed to overcome friction, the more force you have available to tighten the joint. Try slipping a bicycle handle bar grip onto bare chrome plated handle bars and you'll see what a fight it can be. Now, lubricate the handle bars so the rubber grip slides over a thin film of oil, and you'll see what a difference friction makes.

It's like a car. The more power used to drive the power steering pump, the air conditioning compressor, the water pump and the alternator, the less power you have left over for turning the wheels.

On Mon, 13 May 2013 02:57:23 +0200, nestork
wrote:


Vic Smith;3061096 Wrote:

"Overtightening" because threads are lubed makes no sense to me.


It does to me.

The less force needed to overcome friction, the more force you have
available to tighten the joint. Try slipping a bicycle handle bar grip
onto bare chrome plated handle bars and you'll see what a fight it can
be. Now, lubricate the handle bars so the rubber grip slides over a
thin film of oil, and you'll see what a difference friction makes.

It's like a car. The more power used to drive the power steering pump,
the air conditioning compressor, the water pump and the alternator, the
less power you have left over for turning the wheels.


What does any of this have to do with tapered pipe threads?

On Sun, 12 May 2013 16:05:09 -0400, clare wrote:

Just because it is a lubricand doesn't mean it is not also
a sealer - and vise versa.

I ended up using the 2-in-one lubricant + sealer, after
taking pains to remove all vestiges of the Teflon tape.

BTW, do we lubricate the unions?
http://www3.picturepush.com/photo/a/...g/12918676.jpg

I think they go on dry ... but I also thought Teflon tape was
to be used on the threaded fittings (and that was wrong).

On Sun, 12 May 2013 19:01:18 -0500, Vic Smith wrote:

You want to look at how many threads should still be
exposed for a good fit, and tighten to there.

Here are the exposed threads on what I ended up with on
the schedule 40 fitting:
http://www1.picturepush.com/photo/a/...g/12918709.jpg

And here are the exposed threads on the schedule 80 nipple
(this is the one that I had the Teflon tape + sealant) after
I removed the Teflon tape and sealant due to what I read
in this thread - and started over:
http://www1.picturepush.com/photo/a/...0/12918679.jpg

On Sun, 12 May 2013 19:27:28 -0400, krw wrote:

It doesn't matter what order you apply them in, as long as
you apply the first properly, and NEVER apply the 2nd.

You still have to apply the correct one first

UPDATE:

Given the wonderful advice in this thread, I ripped out all the
threaded fittings today, and started over - this time with *just*
the PVC sealant+lubricant (and specifically, *no Teflon tape*).
http://www4.picturepush.com/photo/a/...0/12918677.jpg

On this second pass, I put only a bead of paste on the threads:
http://www5.picturepush.com/photo/a/...0/12918678.jpg

I then tightened the fitting two turns after hand tight:
http://www1.picturepush.com/photo/a/...0/12918679.jpg

I also replaced the schedule 40 fitting by putting the sealer on:
http://www1.picturepush.com/photo/a/...0/12918704.jpg

I wasn't sure how thick the sealant was supposed to go on though:
http://www2.picturepush.com/photo/a/...0/12918705.jpg

As instructed, I then screwed the fitting on only hand tight:
http://www4.picturepush.com/photo/a/...0/12918707.jpg

I used a pipe wrench for the last two turns after hand tight:
http://www5.picturepush.com/photo/a/...0/12918708.jpg

With this being the end result:
http://www1.picturepush.com/photo/a/...0/12918709.jpg

On Mon, 13 May 2013 02:57:23 +0200, nestork
wrote:


Vic Smith;3061096 Wrote:

"Overtightening" because threads are lubed makes no sense to me.


It does to me.

The less force needed to overcome friction, the more force you have
available to tighten the joint. Try slipping a bicycle handle bar grip
onto bare chrome plated handle bars and you'll see what a fight it can
be. Now, lubricate the handle bars so the rubber grip slides over a
thin film of oil, and you'll see what a difference friction makes.

It's like a car. The more power used to drive the power steering pump,
the air conditioning compressor, the water pump and the alternator, the
less power you have left over for turning the wheels.
Except if you follow instructions and tighten the specified 1.5?
turns after contact it doesn't matter how much or how little friction
there is in the joint. the specified number of turns after contact
will ALWAYS give the same fit - and the same amount of thread
deformation or fitting swell.

On May 12, 5:00*am, "HeyBub" wrote:
DD_BobK wrote:

I'd use one or the other, not both.

Teflon is primarily a lubricant and is most effective on NPT
fittings. NPT fittings change their pitch so that the connected
pieces deform the pipe threads more and more making the seal.

Other types of threading do not change the thread pitch (if there is
any involved in the seal), so any imperfections are better dealth
with by a pipe sealant.

A lot incorrect information.....

1) Teflon is primarily a lubricant * it is material to seal the
naturally occurring / designed in clearance between internal &
external pipe threads.

2) NPT fittings change their pitch so that the connected pieces deform
the pipe *threads more and more making the seal. incorrect for
ubiquitous / normally used / everyday *NPT threads. *

NPT pipe threads do NOT have interference thread forms, they do not
change pitch.
If they deformed, how could new fittings be used on old pipe?

"Dry fit" pipe threads do exist & do seal based on interference but
they are seldom encountered in daily life.
I used them ~30 year on military hydraulic systems where dope & tape
were prohibited. *Dry seal threads are a bitch to use, they sucked...
a major PITA. *Be thankful that everyday threads are not as you
describe.

Take a look at the wikipedia article on pipe threads.

Likewise, look at the article on thread sealing tape:

"One of the defining characteristics of PTFE (Teflon) is how good it is at
defeating friction. The use of PTFE tape in tapered pipe threads performs a
lubricating function, which more easily allows the threads to be screwed
together, to the point of deformation, which is what creates the seal."

HB-

Please provide sight / link for following.....

""One of the defining characteristics of PTFE (Teflon) is how good it
is at
defeating friction. The use of PTFE tape in tapered pipe threads
performs a
lubricating function, which more easily allows the threads to be
screwed
together, to the point of deformation, which is what creates the
seal."


to the point of deformation

I assume you mean deformation of the threads? & not the tape?

Internal & external threads of NPT threads type do not interfere with
each other.
Take a look in Machinery's Handbook to get an idea of the design of
NPT threads.
There is a designed in & manufactured in clearance between the crests
& the valleys..
thus creating a spiral leak path that needs a sealant not a lube.

cheers
Bob

On May 12, 1:00*pm, wrote:
On Sun, 12 May 2013 04:49:41 +0000 (UTC), Danny D
wrote:









On Sat, 11 May 2013 12:34:33 -0700, Oren wrote:

Again. Is the sealant you used intended for PVC pool pipe fittings?

I called RectorSeal while I was at Home Depot and they said to use
the red tube that I bought (and not the red jar, which was for metals).

The red tube says it's for "plastics", so that's what I used over the
Teflon tape.

Now I understand, from Vic Smith's article, that Teflon tape is a no-no;
and I understand that *lubrication* is a no no ... so it appears *all*
the tubes of sealant I bought from Home Depot are wrong.
http://www5.picturepush.com/photo/a/...g/12900978.jpg

I wonder if the local plumbing and irrigation supply places know this
stuff?

*Just because the recommended red stuff works as a lubricant doesn't
mean it's not the right stuff. Virtually ANY sealant will "act as" a
lubricant.

Virtually ANY sealant will "act as" a lubricant.

Excellent point. OP needs to apply a bit of common sense & stop
looking for the holy grail.

cheers
Bob

On May 13, 4:28*am, DD_BobK wrote:
On May 12, 5:00*am, "HeyBub" wrote:









DD_BobK wrote:

I'd use one or the other, not both.

Teflon is primarily a lubricant and is most effective on NPT
fittings. NPT fittings change their pitch so that the connected
pieces deform the pipe threads more and more making the seal.

Other types of threading do not change the thread pitch (if there is
any involved in the seal), so any imperfections are better dealth
with by a pipe sealant.

A lot incorrect information.....

1) Teflon is primarily a lubricant * it is material to seal the
naturally occurring / designed in clearance between internal &
external pipe threads.

2) NPT fittings change their pitch so that the connected pieces deform
the pipe *threads more and more making the seal. incorrect for
ubiquitous / normally used / everyday *NPT threads. *

NPT pipe threads do NOT have interference thread forms, they do not
change pitch.
If they deformed, how could new fittings be used on old pipe?

"Dry fit" pipe threads do exist & do seal based on interference but
they are seldom encountered in daily life.
I used them ~30 year on military hydraulic systems where dope & tape
were prohibited. *Dry seal threads are a bitch to use, they sucked....
a major PITA. *Be thankful that everyday threads are not as you
describe.

Take a look at the wikipedia article on pipe threads.

Likewise, look at the article on thread sealing tape:

"One of the defining characteristics of PTFE (Teflon) is how good it is at
defeating friction. The use of PTFE tape in tapered pipe threads performs a
lubricating function, which more easily allows the threads to be screwed
together, to the point of deformation, which is what creates the seal."

HB-

Please provide sight / link for *following.....

""One of the defining characteristics of PTFE (Teflon) is how good it
is at
defeating friction. The use of PTFE tape in tapered pipe threads
performs a
lubricating function, which more easily allows the threads to be
screwed
together, to the point of deformation, which is what creates the
seal."

to the point of deformation

I assume you mean deformation of the threads? *& not the tape?

Internal & external threads of NPT threads type do not interfere with
each other.
Take a look in Machinery's Handbook to get an idea of the design of
NPT threads.
There is a designed in & manufactured in clearance between the crests
& the valleys..
thus creating a spiral leak path that needs a sealant not a lube.

cheers
Bob

I should add to be clear....

NPT threads need a sealant to seal the spiral leak path.
NPT threads do not seal by thread deformation.

Hint: To do a practical proof of want I knew to be the design intent
of NPT threads,
I did the lube alone assembly of NPT pipe & fittings.... they leak no
matter how tight.
I used oil so that no "sealant" was present.

cheers
Bob

On Mon, 13 May 2013 04:43:10 -0700, DD_BobK wrote:

NPT threads need a sealant to seal the spiral leak path.
NPT threads do not seal by thread deformation.

Are the union threads NPT also?

On May 12, 9:46*pm, Danny D wrote:
On Sun, 12 May 2013 16:05:09 -0400, clare wrote:
*Just because it is a lubricand doesn't mean it is not also
a sealer - and vise versa.

I ended up using the 2-in-one lubricant + sealer, after
taking pains to remove all vestiges of the Teflon tape.

BTW, do we lubricate the unions?
*http://www3.picturepush.com/photo/a/...g/12918676.jpg

I think they go on dry ... but I also thought Teflon tape was
to be used on the threaded fittings (and that was wrong).

You can put some silicone lube on the rubber o-ring. That is
what seals it. Nothing goes on the threads.

On May 12, 8:01*pm, Vic Smith wrote:
On Sun, 12 May 2013 17:18:09 +0000 (UTC), Danny D
wrote:



The only proscription against that stuff, based on
the Vic Smith article, was the fact it also lubricates
as it seals.

Please quit saying that's "my article." *I didn't write that, I just
cited it.

I think we all understood that's what he meant.



*I have no experience at all with threaded plastic pipe.
And I'm not buying all this emphasis on "lubricate vs non-lubricate."
As long as it's compatible with the plastic, seals the threads, and
doesn't harden up, it should work.

I agree. For that matter, Teflon tape is widely used and if it
made a huge difference, there would be leaking fittings everywhere.
Yet, lots of people, including many pros are using tape.



"Overtightening" because threads are lubed makes no sense to me.

Imagine pushing a v shaped wedge into a v cut opening
in a piece of plastic or metal. The further in the wedge goes,
the more splitting force you have. Do you think with the same
amount of force applied to the wedge, it will go in further with
or without lube?



One guy's "feel" for tight isn't the same as another's. *You use a
different length wrench, the feel changes.

Agree. That's where experience counts. And why perhaps
those with little experience could wind up in trouble using
Teflon tape while others have used it and it's worked fine.


Likewise, these guys are saying stuff like "2 turns past
finger-tight." *That fine if there's no burrs on the threads, the
threads are consistently formed, and everybody has the same fingers.
That's not realistic. *What's more realistic is a consistent taper and
consistent thread count.
You want to look at how many threads should still be exposed for a
good fit, and tighten to there. lube or no lube. *I can see that with
galvanized and know when the male is inserted far enough .
The force used to get there can vary depending on the thread
condition, but threads exposed is the best indication of what force
the taper is putting on the female, and when to stop cranking down.

And there I disagree. Joints are tight when they are tight.
If you try to rely on looking at how many threads are showing,
I think you're in for trouble. How do you even know that the
number of threads is consistent from one pipe to another?
For example, if you get a piece of pipe cut and threaded at
HD, is piece A going to have exactly the same number of threads
as piece B? You just have to develop a feel for it and learn
from experience.


Anyway, that's how I'd approach tightening plastic too.
But until I did it, it's still a guess to me.

On May 12, 10:26*pm, Danny D wrote:
On Sun, 12 May 2013 19:27:28 -0400, krw wrote:
It doesn't matter what order you apply them in, as long as
you apply the first properly, and NEVER apply the 2nd.

You still have to apply the correct one first

UPDATE:

Given the wonderful advice in this thread, I ripped out all the
threaded fittings today, and started over - this time with *just*
the PVC sealant+lubricant (and specifically, *no Teflon tape*).
*http://www4.picturepush.com/photo/a/...0/12918677.jpg

On this second pass, I put only a bead of paste on the threads:
*http://www5.picturepush.com/photo/a/...0/12918678.jpg

I then tightened the fitting two turns after hand tight:
*http://www1.picturepush.com/photo/a/...0/12918679.jpg

I also replaced the schedule 40 fitting by putting the sealer on:
*http://www1.picturepush.com/photo/a/...0/12918704.jpg

I wasn't sure how thick the sealant was supposed to go on though:
*http://www2.picturepush.com/photo/a/...0/12918705.jpg

As instructed, I then screwed the fitting on only hand tight:
*http://www4.picturepush.com/photo/a/...0/12918707.jpg

I used a pipe wrench for the last two turns after hand tight:
*http://www5.picturepush.com/photo/a/...0/12918708.jpg

With this being the end result:
*http://www1.picturepush.com/photo/a/...0/12918709.jpg

I would be using channel lock pliers, not a big honking pipe wrench.
No need for anywhere the amount of force you can get with that
wrench. And by using pliers, you have a better feel for the force
being applied, less likely to overtighten, etc. Plus it's easier to
handle too.

On Mon, 13 May 2013 06:09:12 -0700, wrote:

I agree. For that matter, Teflon tape is widely used and if it made a
huge difference, there would be leaking fittings everywhere.
Yet, lots of people, including many pros are using tape.

I should also note that the original fittings certainly had
Teflon tape on them, presumably from the professional installers.

I did have leaks in the two inlets to the pool pumps though; but
who knows why (hopefully they're fixed with the new fittings).

On Mon, 13 May 2013 06:13:51 -0700, wrote:

I would be using channel lock pliers, not a big honking pipe wrench.

I didn't know what people use!

Thanks for that advice.

Caryn:

"NPT" means "National Pipe Thread", and NPT threads are a tapered thread, like this:



A waterproof seal is achieved by some soft material (like teflon tape or pipe dope) being compressed between the male and female threads as the joint is tightened.

Other threads, like the threads on a bolt or a light bulb are not tapered:



In plumbing, you can tell which threads to put teflon tape, pipe dope or thread sealer on by just asking yourself the question: "In this connection, is the water tight seal made by the threads themselves?" If so, then you need pipe dope, teflon tape or thread sealer on those threads. If not, then you shouldn't put anything at all on those threads.

So, in the case of the union shown he



The two threads where pipes screw in at each END of the union are NPT threads and would need pipe dope, teflon tape or thread sealant on them because it's the threads themselves that make the water proof seal at those joints.

However, the coarser thread on the collar of the union is not a tapered NPT thread and doesn't need pipe dope, teflon tape or thread sealant on it because it doesn't make a water proof seal. The water leakage path through those collar threads is prevented by the O-ring shown inside that union (as seen in the picture). It's that O-ring that prevents water leakage through the collar threads, not the threads on the collar wedging themselves together as the joint is tightened like NPT threads do.

So, with the above union, you would put pipe dope, teflon tape or thread sealant when screwing the union onto the pipes it's meant to connect. But, you wouldn't put anything on the collar threads when connecting the two halves of the union together. The teflon tape, pipe dope or thread sealant would prevent leakage through the pipe threads, and the O-ring prevents leakage though the collar threads.

Hope this helps.

On Mon, 13 May 2013 01:46:56 +0000 (UTC), Danny D
wrote:


BTW, do we lubricate the unions?
http://www3.picturepush.com/photo/a/...g/12918676.jpg

No. Just the O-ring (pool silicone lube). Make sure the union mates
properly and the O-ring seals as needed.

And example is your union on the filter you removed. Nothing on the
threads.

On Mon, 13 May 2013 06:13:51 -0700 (PDT), "
wrote:

On May 12, 10:26*pm, Danny D wrote:
On Sun, 12 May 2013 19:27:28 -0400, krw wrote:
It doesn't matter what order you apply them in, as long as
you apply the first properly, and NEVER apply the 2nd.

You still have to apply the correct one first

UPDATE:

Given the wonderful advice in this thread, I ripped out all the
threaded fittings today, and started over - this time with *just*
the PVC sealant+lubricant (and specifically, *no Teflon tape*).
*http://www4.picturepush.com/photo/a/...0/12918677.jpg

On this second pass, I put only a bead of paste on the threads:
*http://www5.picturepush.com/photo/a/...0/12918678.jpg

I then tightened the fitting two turns after hand tight:
*http://www1.picturepush.com/photo/a/...0/12918679.jpg

I also replaced the schedule 40 fitting by putting the sealer on:
*http://www1.picturepush.com/photo/a/...0/12918704.jpg

I wasn't sure how thick the sealant was supposed to go on though:
*http://www2.picturepush.com/photo/a/...0/12918705.jpg

As instructed, I then screwed the fitting on only hand tight:
*http://www4.picturepush.com/photo/a/...0/12918707.jpg

I used a pipe wrench for the last two turns after hand tight:
*http://www5.picturepush.com/photo/a/...0/12918708.jpg

With this being the end result:
*http://www1.picturepush.com/photo/a/...0/12918709.jpg

I would be using channel lock pliers, not a big honking pipe wrench.
No need for anywhere the amount of force you can get with that
wrench. And by using pliers, you have a better feel for the force
being applied, less likely to overtighten, etc. Plus it's easier to
handle too.

Pipe wrenches have the wrong jaws, too. They're curved, have a moving
jaw, and have teeth, all of which are designed to bite into a round
pipe. None of which is required for unions and certainly isn't wanted
for PVC.

On Mon, 13 May 2013 02:26:13 +0000 (UTC), Danny D
wrote:

On this second pass, I put only a bead of paste on the threads:
http://www5.picturepush.com/photo/a/...0/12918678.jpg


Can you just be bit more sloppier, not enough on the pipe. G


I wasn't sure how thick the sealant was supposed to go on though:
http://www2.picturepush.com/photo/a/...0/12918705.jpg


Almost perfect, but not sloppy enough.

I used a pipe wrench for the last two turns after hand tight:
http://www5.picturepush.com/photo/a/...0/12918708.jpg


LMAO

On Mon, 13 May 2013 13:19:23 +0000 (UTC), Danny D
wrote:

On Mon, 13 May 2013 06:09:12 -0700, wrote:

I agree. For that matter, Teflon tape is widely used and if it made a
huge difference, there would be leaking fittings everywhere.
Yet, lots of people, including many pros are using tape.

I should also note that the original fittings certainly had
Teflon tape on them, presumably from the professional installers.


If you look back to the photo of when you removed the strainer fitting
with the tape, the tape did not extend the length of the threads. It
was applied incorrectly from the start. A PVC sealant should have been
used instead of tape (IMO).

On May 13, 6:19*am, Danny D wrote:
On Mon, 13 May 2013 06:09:12 -0700, wrote:
I agree. *For that matter, Teflon tape is widely used and if it made a
huge difference, there would be leaking fittings everywhere.
Yet, lots of people, including many pros are using tape.

I should also note that the original fittings certainly had
Teflon tape on them, presumably from the professional installers.

I did have leaks in the two inlets to the pool pumps though; but
who knows why (hopefully they're fixed with the new fittings).

" professional installers" ??? yeah, right!
from the layout, they look like hacks

On May 13, 1:41*pm, DD_BobK wrote:
On May 13, 6:19*am, Danny D wrote:

On Mon, 13 May 2013 06:09:12 -0700, wrote:
I agree. *For that matter, Teflon tape is widely used and if it made a
huge difference, there would be leaking fittings everywhere.
Yet, lots of people, including many pros are using tape.

I should also note that the original fittings certainly had
Teflon tape on them, presumably from the professional installers.

I did have leaks in the two inlets to the pool pumps though; but
who knows why (hopefully they're fixed with the new fittings).

" professional installers" *??? yeah, right!
from the layout, they look like hacks

+++++1

On Mon, 13 May 2013 09:09:37 -0700, Oren wrote:

Can you just be bit more sloppier, not enough on the pipe. G

Part of the problem is taking pictures without getting
the goop on the camera, so I tried to use only one hand
for putting on the goop while the other hand held the camera ...

On Mon, 13 May 2013 19:05:47 +0000 (UTC), Danny D
wrote:

On Mon, 13 May 2013 09:09:37 -0700, Oren wrote:

Can you just be bit more sloppier, not enough on the pipe. G

Part of the problem is taking pictures without getting
the goop on the camera, so I tried to use only one hand
for putting on the goop while the other hand held the camera ...



That just sounds nasty!

On Mon, 13 May 2013 10:51:04 -0700 (PDT), "
wrote:

" professional installers" *??? yeah, right!
from the layout, they look like hacks

+++++1

I wager a hazard, that the pool cost around 200G new.

Danny D:

From what I can see, you're putting on way too much sealer on those threads. I don't think it will do any harm, but unless you're catching what comes dripping out of that joint as you tighten it, then you're just wasting the stuff.

I would put a much lighter coat of thread sealant on your male threads.

And, of course, I'd try to be sloppy about it.