When fastening together plumbing with brass screw fittings how many
turns of PTFE tape is normal to wrap around the threads?

--
David in Normandy.

On Fri, 15 May 2009 15:20:48 +0200, David in Normandy wrote:

When fastening together plumbing with brass screw fittings how many
turns of PTFE tape is normal to wrap around the threads?

How long's a piece of string?

I generally give it a couple of turns at the leading end of the screw,
building up more toward the back making a sort of cone shape.

One of those things you learn by experience. And PTFE tape is cheap :-)


--
John Stumbles -- http://yaph.co.uk

87.5% of statistics are made up

On 15 May, 14:20, David in Normandy
wrote:
When fastening together plumbing with brass screw fittings how many
turns of PTFE tape is normal to wrap around the threads?

--
David in Normandy.

Enough to stop it falling off (i.e. a bit more than one) and then not
too much, except for radiator tails which need loads (4-5 wraps) As
you look at the thread end, wrap the tape clockwise, then screwing it
in won't unwrap the tape.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember David in Normandy
saying something like:

When fastening together plumbing with brass screw fittings how many
turns of PTFE tape is normal to wrap around the threads?

Twelve. Or six. Or fourteen.
Who knows?
Nobody.
Try eight to start with and if it's too loose put more on.

David in Normandy wrote:

When fastening together plumbing with brass screw fittings how many
turns of PTFE tape is normal to wrap around the threads?

If you are just using it for lubrication (rather than sealing on the
threads) two or three is ample. For a proper seal on a thread you
usually need more.

The difficult ones to judge are things like taps into wall mounting
bosses where you need enough turns in the right place to not only seal
but also bring the tap to a suitably upright position. John's taper
approach works well there. For some things hemp as boss white are still
easier (immersion heaters for example).


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Fri, 15 May 2009 20:04:40 +0100, John Rumm wrote:

The difficult ones to judge are things like taps into wall mounting
bosses where you need enough turns in the right place to not only seal
but also bring the tap to a suitably upright position.

Loctite thread sealing cord (like dental floss on steroids) is good for
this since you can back it off if you need and it'll still seal, unlike
PTFE.


... For some things hemp as boss white are still
easier (immersion heaters for example).

Aaargh, noooo! Apart from the fact that it's illegal (not suitable for
potable water) think of the poor sod who's got to remove it next time, when
the boss white's set like rock. PTFE is great for this: lubricates the
thread and helps it to seal if the fibre washer's a bit reluctant. I apply
a couple of turns to the main thread and bunch a load up by the flange.

--
John Stumbles -- http://yaph.co.uk

How odd of God But not so odd as those who choose
To choose the Jews A Jewish god, yet spurn the Jews

YAPH coughed up some electrons that declared:

On Fri, 15 May 2009 20:04:40 +0100, John Rumm wrote:

The difficult ones to judge are things like taps into wall mounting
bosses where you need enough turns in the right place to not only seal
but also bring the tap to a suitably upright position.

Loctite thread sealing cord (like dental floss on steroids) is good for
this since you can back it off if you need and it'll still seal, unlike
PTFE.


... For some things hemp as boss white are still
easier (immersion heaters for example).

Aaargh, noooo! Apart from the fact that it's illegal (not suitable for
potable water)

Do immersion heaters heat potable water (assuming potable=drinking as
opposed to bath filling)?

think of the poor sod who's got to remove it next time,
when the boss white's set like rock.

But I agree with this... Boss white + hemp: once it goes off it never comes
off Especially on something with the diameter of an immersion supported
by an expensive but somewhat fliddy copper tank. Think it'd use it on rads,
but probably not much else.

I wish they did boss green without the fibre crap in it - I tried some, it's
bloody useless. Falls off before you can get the joint together.

Boss white says non-toxic - is it legal to use it with PTFE string rather
than hemp, say on a bib tap outside? (Thought it was the hemp being a bug
breeding ground that was the main problem) I find PTFE tape on a such taps
is a PITA. A tug on the hose the wrong way and the ruddy tap starts
undoing. That's one time I do want the whole lot to set solid.

PTFE is great for this: lubricates
the thread and helps it to seal if the fibre washer's a bit reluctant. I
apply a couple of turns to the main thread and bunch a load up by the
flange.


What do you reckon about the liquid thread sealants that have appeared in
recent times?

Cheers

Tim

"Tim S" wrote in message
...
YAPH coughed up some electrons that declared:

On Fri, 15 May 2009 20:04:40 +0100, John Rumm wrote:

The difficult ones to judge are things like taps into wall mounting
bosses where you need enough turns in the right place to not only seal
but also bring the tap to a suitably upright position.

Loctite thread sealing cord (like dental floss on steroids) is good for
this since you can back it off if you need and it'll still seal, unlike
PTFE.


... For some things hemp as boss white are still
easier (immersion heaters for example).

Aaargh, noooo! Apart from the fact that it's illegal (not suitable for
potable water)

Do immersion heaters heat potable water (assuming potable=drinking as
opposed to bath filling)?

think of the poor sod who's got to remove it next time,
when the boss white's set like rock.

But I agree with this... Boss white + hemp: once it goes off it never
comes
off Especially on something with the diameter of an immersion supported
by an expensive but somewhat fliddy copper tank. Think it'd use it on
rads,
but probably not much else.

I wish they did boss green without the fibre crap in it - I tried some,
it's
bloody useless. Falls off before you can get the joint together.

Boss white says non-toxic - is it legal to use it with PTFE string rather
than hemp, say on a bib tap outside? (Thought it was the hemp being a bug
breeding ground that was the main problem) I find PTFE tape on a such taps
is a PITA. A tug on the hose the wrong way and the ruddy tap starts
undoing. That's one time I do want the whole lot to set solid.

PTFE is great for this: lubricates
the thread and helps it to seal if the fibre washer's a bit reluctant. I
apply a couple of turns to the main thread and bunch a load up by the
flange.


What do you reckon about the liquid thread sealants that have appeared in
recent times?

Cheers

Tim

I just hope the OP didn't mean Compression Fittings!

On Fri, 15 May 2009 22:31:50 +0100, Tim S wrote:

Do immersion heaters heat potable water (assuming potable=drinking as
opposed to bath filling)?

yes: technically it's potable: rules apply



--
John Stumbles -- http://yaph.co.uk

Just because you're paranoid doesn't mean they're not out to get you.

On Fri, 15 May 2009 22:31:50 +0100, Tim S wrote:

I wish they did boss green without the fibre crap in it - I tried some, it's
bloody useless. Falls off before you can get the joint together.

Boss white says non-toxic - is it legal to use it with PTFE string rather
than hemp, say on a bib tap outside? (Thought it was the hemp being a bug
breeding ground that was the main problem)

Traditional Boss White contains Linseed oil (I think) which (AIUI) is why
it's a no-no for potable. The newer (and harder to find) Boss White
Universal is OK for potable as well as gas. My Boss Green is relegated to
a corner of the van, awaiting a clear-out.

I find PTFE tape on a such
taps is a PITA. A tug on the hose the wrong way and the ruddy tap starts
undoing. That's one time I do want the whole lot to set solid.

What do you reckon about the liquid thread sealants that have appeared
in recent times?

Tried the Talon stuff but didn't get on with it, and the blue stuff
Toolstation do (True Blue?) but find between Loctite string, Boss universal
and PTFE I don't use it any more. (It was messy and didn't stick things
tight, like outside taps: a judicious amount of Loctite thread is my
current recipie for that.)



--
John Stumbles -- http://yaph.co.uk

Women always generalise

YAPH coughed up some electrons that declared:

On Fri, 15 May 2009 22:31:50 +0100, Tim S wrote:

Do immersion heaters heat potable water (assuming potable=drinking as
opposed to bath filling)?

yes: technically it's potable: rules apply




Oh - OK then.

I'll file that in the grey gooey wikipedia...

That must mean that primatic cylinders are now banned (potential linkage of
potable water with black mouldy scunge in rads)?...

YAPH coughed up some electrons that declared:

On Fri, 15 May 2009 22:31:50 +0100, Tim S wrote:

I wish they did boss green without the fibre crap in it - I tried some,
it's bloody useless. Falls off before you can get the joint together.

Boss white says non-toxic - is it legal to use it with PTFE string rather
than hemp, say on a bib tap outside? (Thought it was the hemp being a bug
breeding ground that was the main problem)

Traditional Boss White contains Linseed oil (I think) which (AIUI) is why
it's a no-no for potable.

Yes, it certainly smells that way. I like the smell.

The newer (and harder to find) Boss White
Universal is OK for potable as well as gas. My Boss Green is relegated to
a corner of the van, awaiting a clear-out.

I see it's not just me then, re Green Useless Stuff.

Thanks for the tip on the Universal - I'll see if I can get one for my
toolbox.

I find PTFE tape on a such
taps is a PITA. A tug on the hose the wrong way and the ruddy tap starts
undoing. That's one time I do want the whole lot to set solid.

What do you reckon about the liquid thread sealants that have appeared
in recent times?

Tried the Talon stuff but didn't get on with it, and the blue stuff
Toolstation do (True Blue?) but find between Loctite string, Boss
universal and PTFE I don't use it any more. (It was messy and didn't stick
things tight, like outside taps: a judicious amount of Loctite thread is
my current recipie for that.)

Just to be clear on the taps, you mean loctite 572 (pipe sealant) as opposed
to regular Loctite threadlock compounds (as in normally used on bolts etc)?

Cheers

Tim

YAPH wrote:

... For some things hemp as boss white are still
easier (immersion heaters for example).

Aaargh, noooo! Apart from the fact that it's illegal (not suitable for
potable water) think of the poor sod who's got to remove it next time, when

Well to be fair - I have the potable version of something similar (not
actually made by Boss)...

(not actually sure I would want to drink gravity fed hot water from a
tank anyway, regardless of what thread sealer has been used ;-))

the boss white's set like rock. PTFE is great for this: lubricates the
thread and helps it to seal if the fibre washer's a bit reluctant. I apply
a couple of turns to the main thread and bunch a load up by the flange.

Last time I needed to resort to this technique it was an immersion boss
that was a very sloppy fit in the tank, and the washer such that it was,
was not really up to the job. I had two attempts with PTFE (using first
copious, and then obscene amounts), and it still was not having it!




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John wrote:

I just hope the OP didn't mean Compression Fittings!


No I meant brass screw joints. For example I had an 1/2" male to male
joint I needed to screw into a pressure reduction valve near the cold
water inlet to the house. So I assume from your comment that the tape
should not be used on compression fittings? I did wonder. Just after the
joint mentioned above there was an compression fitting and I guessed not
to use tape on that since the olive should be stopping the water leaking
not the threads on the joint. The rest of the plumbing from there is all
soldered end feed joints.

I just wasn't sure how many winds of PTFE tape to do on the screw joint.
In the end I did 4. The joint screwed together firmly without seeming
too tight or too sloppy. I've since turned the mains water back on again
and it isn't leaking so it must have been ok.

My plumbing book mentions putting the tape on in the correct direction
so it doesn't unravel while being assembled, it just failed to mention
how many turns. I don't like guessing if there is a "best practice" to
follow.

--
David in Normandy.

On Fri, 15 May 2009 23:20:54 +0100, Tim S wrote:

Just to be clear on the taps, you mean loctite 572 (pipe sealant) as
opposed to regular Loctite threadlock compounds (as in normally used on
bolts etc)?

Not sure the number but thread in a red plastic dispenser, bit like dental
floss. Screwfix do it.



--
John Stumbles -- http://yaph.co.uk

You'll make some woman a fine husband, Dr Frankenstein

On Sat, 16 May 2009 09:34:50 +0200, David in Normandy wrote:

John wrote:

I just hope the OP didn't mean Compression Fittings!


No I meant brass screw joints. For example I had an 1/2" male to male
joint I needed to screw into a pressure reduction valve near the cold
water inlet to the house. So I assume from your comment that the tape
should not be used on compression fittings? I did wonder. Just after the
joint mentioned above there was an compression fitting and I guessed not
to use tape on that since the olive should be stopping the water leaking
not the threads on the joint. The rest of the plumbing from there is all
soldered end feed joints.

I just wasn't sure how many winds of PTFE tape to do on the screw joint.
In the end I did 4. The joint screwed together firmly without seeming
too tight or too sloppy. I've since turned the mains water back on again
and it isn't leaking so it must have been ok.

My plumbing book mentions putting the tape on in the correct direction
so it doesn't unravel while being assembled, it just failed to mention
how many turns. I don't like guessing if there is a "best practice" to
follow.

When I first used PTFE tape (many fortnights ago) I learned 2 things very
quickly:

direction of tape(!)
try the thread bare to see how much slop is available

With BSPT, the amount of tape can be useful to control depth if there's a
risk of the joint bottoming out.
--
Peter.
You don't understand Newton's Third Law of Motion?
It's not rocket science, you know.

YAPH coughed up some electrons that declared:

On Fri, 15 May 2009 23:20:54 +0100, Tim S wrote:

Just to be clear on the taps, you mean loctite 572 (pipe sealant) as
opposed to regular Loctite threadlock compounds (as in normally used on
bolts etc)?

Not sure the number but thread in a red plastic dispenser, bit like dental
floss. Screwfix do it.



Ah - we're talking about different things... 572 is a liquid thread
lock/sealer, made for plumbing (gas too apparantly - although I cannot see
that or WRAS approval on Loctite's site, only Loctite 55 is mentioned as
being CORGI approved and nothing is mentioned as WRAS).

Think I'll go with the dental floss (have some already) and Universal. Seems
a bombproof combination I can use anywhere if required.

Cheers

Tim

David in Normandy wrote:
John wrote:

I just hope the OP didn't mean Compression Fittings!


No I meant brass screw joints. For example I had an 1/2" male to male
joint I needed to screw into a pressure reduction valve near the cold
water inlet to the house. So I assume from your comment that the tape
should not be used on compression fittings? I did wonder. Just after
the joint mentioned above there was an compression fitting and I
guessed not to use tape on that since the olive should be stopping
the water leaking not the threads on the joint. The rest of the
plumbing from there is all soldered end feed joints.

There is always a controversy around here re PTFE tape on compression
fittings. You are right, they seal on the olive not the thread, but many,
me included put a wind or two around the thread because it makes doing it up
tight easier. IOW its used as a lubricant not a seal.



--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

PeterC wrote:
With BSPT, the amount of tape can be useful to control depth if there's a
risk of the joint bottoming out.

What is BSPT ?

--
David in Normandy.

"David in Normandy" wrote in message
...

My plumbing book mentions putting the tape on in the correct direction so
it doesn't unravel while being assembled, it just failed to mention how
many turns. I don't like guessing if there is a "best practice" to follow.


When I bought some PTFE tape for gas usage, it gave instructions on the tape
reel, - One lap as shown, (small drawing of tape on thread), 50% overlap,
For BS21 threads up to 2".

The Medway Handyman wrote:
There is always a controversy around here re PTFE tape on compression
fittings. You are right, they seal on the olive not the thread, but many,
me included put a wind or two around the thread because it makes doing it up
tight easier. IOW its used as a lubricant not a seal.


Right. Sounds logical. I'll put a couple of winds on myself then with
compression fittings; though I'm trying to avoid compression fittings
where possible - I could never guess how tight to do them and have had a
fair number of leaks and drips when I've used them previously. Too slack
they leak, too tight and the olive distorts and they leak. Could do with
a torque wrench at an ideal setting.

My end feed solder joints seem much more reliable and error proof - well
so far. When I turn on my next stop tap I'll be testing around 40
joints! Fingers crossed as I don't fancy re-soldering any - some are
very inconvenient to get to.

--
David in Normandy.

In article ,
John Rumm wrote:
(not actually sure I would want to drink gravity fed hot water from a
tank anyway, regardless of what thread sealer has been used ;-))

You're likely to get some on lips etc when showering or bathing?

--
*Why is "abbreviated" such a long word?

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
The Medway Handyman wrote:
There is always a controversy around here re PTFE tape on compression
fittings. You are right, they seal on the olive not the thread, but
many, me included put a wind or two around the thread because it makes
doing it up tight easier. IOW its used as a lubricant not a seal.

I use a turn or two round the olive - and always have done. Not going to
stop now regardless of what others say. ;-)

--
*Forget the Joneses, I keep us up with the Simpsons.

Dave Plowman London SW
To e-mail, change noise into sound.

On Sat, 16 May 2009 12:31:33 +0200, David in Normandy wrote:

PeterC wrote:
With BSPT, the amount of tape can be useful to control depth if there's a
risk of the joint bottoming out.

What is BSPT ?

British Standard Pipe Taper Thread
--
Peter.
You don't understand Newton's Third Law of Motion?
It's not rocket science, you know.

In article , YAPH
wrote:
Tim S said:
Boss white says non-toxic - is it legal to use it with PTFE string
rather than hemp, say on a bib tap outside? (Thought it was the hemp
being a bug breeding ground that was the main problem)

Traditional Boss White contains Linseed oil (I think) which (AIUI) is
why it's a no-no for potable.

Linseed (and its oil) are edible and sold as health supplements with omega3
so perhaps its the hemp that's thee problem

John

--
John Mulrooney
NOTE Email address IS correct but might not be checked for a while.

In the land of the blind, the one eyed man is Prime Minister....

In article ,
Dave Plowman (News) wrote:
In article ,
John Rumm wrote:
(not actually sure I would want to drink gravity fed hot water from a
tank anyway, regardless of what thread sealer has been used ;-))

You're likely to get some on lips etc when showering or bathing?

I seem to recall a thread some years ago about showers and legionella
That took me 4 goes to spell and still wrong but when I looked it up in
!Dict spelled it correctly without a problem)

John

--
John Mulrooney
NOTE Email address IS correct but might not be checked for a while.

All's fair in love, war and car parking!

On Sat, 16 May 2009 13:44:09 +0100, JTM wrote:

In article , YAPH
wrote:
Tim S said:
Boss white says non-toxic - is it legal to use it with PTFE string
rather than hemp, say on a bib tap outside? (Thought it was the hemp
being a bug breeding ground that was the main problem)

Traditional Boss White contains Linseed oil (I think) which (AIUI) is
why it's a no-no for potable.

Linseed (and its oil) are edible and sold as health supplements with
omega3 so perhaps its the hemp that's thee problem

John
=========================================

You may be right.

An ancient news story (1950s) reported that a recent Asian immigrant
bought a new washing line every week from his local hardware shop. Finding
this a bit strange the shop keeper finally asked the chap why he needed so
many washing lines. The reply was that the washing line, being made from
hemp, was a cheap narcotic smoke akin to marijuana, completely legal and
cheaper than tobacco.

Cic.


--
==========================================
Using Ubuntu Linux
Windows shown the door
==========================================

Dave Plowman (News) coughed up some electrons that declared:

In article ,
John Rumm wrote:
(not actually sure I would want to drink gravity fed hot water from a
tank anyway, regardless of what thread sealer has been used ;-))

You're likely to get some on lips etc when showering or bathing?


Dave - you could get a muddly puddle on your lips and it's unlikey to kill
you. I honesly can't see a trace of linseed oil (or x PPM lead from a
leaded solder joint) making any difference - overkill if you ask me...

Might be an issue in a pipe that often is left standing without regular
flow.

In article ,
Tim S wrote:
Dave Plowman (News) coughed up some electrons that declared:

In article ,
John Rumm wrote:
(not actually sure I would want to drink gravity fed hot water from a
tank anyway, regardless of what thread sealer has been used ;-))

You're likely to get some on lips etc when showering or bathing?


Dave - you could get a muddly puddle on your lips and it's unlikey to
kill you. I honesly can't see a trace of linseed oil (or x PPM lead from
a leaded solder joint) making any difference - overkill if you ask me...

Might be an issue in a pipe that often is left standing without regular
flow.

Before this house I lived in a rented flat - part of a beautiful detached
Victorian house that is now a school. And the huge tank there was lead
lined...

--
*A plateau is a high form of flattery*

Dave Plowman London SW
To e-mail, change noise into sound.

On Sat, 16 May 2009 13:44:09 +0100, JTM wrote:

Linseed (and its oil) are edible

to various life forms, some microbial, as well as humans. If you're going
to consume them you'd be best advised to do so before they've been hanging
around long enough for the bugs to have had first dibs.

--
John Stumbles -- http://yaph.co.uk

Life is nature's way of keeping meat fresh

On Sat, 16 May 2009 07:39:58 +0000, YAPH wrote:

On Fri, 15 May 2009 23:20:54 +0100, Tim S wrote:

Just to be clear on the taps, you mean loctite 572 (pipe sealant) as
opposed to regular Loctite threadlock compounds (as in normally used on
bolts etc)?

Not sure the number but thread in a red plastic dispenser, bit like
dental floss. Screwfix do it.

That'll be loctite 55. Excellent stuff, both for plumbing and teeth.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

On Sun, 17 May 2009 18:14:34 +0000, Ed Sirett wrote:

On Sat, 16 May 2009 07:39:58 +0000, YAPH wrote:

Not sure the number but thread in a red plastic dispenser, bit like
dental floss. Screwfix do it.

That'll be loctite 55. Excellent stuff, both for plumbing and teeth.
^^^^^

You are Desperate Dan and I claim my five pounds!


--
John Stumbles -- http://yaph.co.uk

How odd of God But not so odd as those who choose
To choose the Jews A Jewish god, yet spurn the Jews

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Cicero
saying something like:

An ancient news story (1950s) reported that a recent Asian immigrant
bought a new washing line every week from his local hardware shop. Finding
this a bit strange the shop keeper finally asked the chap why he needed so
many washing lines. The reply was that the washing line, being made from
hemp, was a cheap narcotic smoke akin to marijuana, completely legal and
cheaper than tobacco.

That'd be amazing, considering the hemp plant that's grown for fibre
contains extremely low levels of cannabinoids to start with and
secondly, the fibrous woody stem contains the least of that - ie, bugger
all.
It couldn't possibly be a made-up story now, could it? I mean,
journalists never do that, oh no.