PTFE tape...

Good point. I wondered about PTFE tape for bottom bracket threads.
Seems it's the recommended industry practice to use grease or
anti-seize there. I believe the BB flexes and rocks with crank
rotation. PTFE is pretty thin. Will the tape be cut through and wear
out quickly in this situation?

Quoted message said:

I just discovered that PTFE tape is a good anti seize agent. Clean,
easy to use, cheap. Was I the only one who didn't know? (Shouts of YES!
all round the interweb)

A fellow who tested PTFE on bottom brackets told me it was good for
coarse plumbing threads but tends to get displaced on finer bicycle
threads. For bottom brackets, we use loctite on metal threads and
grease on plastic.

-Sam

flatline said:

Good point. I wondered about PTFE tape for bottom bracket threads.
Seems it's the recommended industry practice to use grease or
anti-seize there. I believe the BB flexes and rocks with crank
rotation. PTFE is pretty thin. Will the tape be cut through and wear
out quickly in this situation?

Quoted message said:

I just discovered that PTFE tape is a good anti seize agent. Clean,
easy to use, cheap. Was I the only one who didn't know? (Shouts of YES!
all round the interweb)

Quoted message said:

For bottom brackets, we use loctite on metal threads

Do you treat all the threads or just the outer few? What Loctite
product do you use?

Quoted message said:

grease on plastic.

Does plastic need anything? Does (lithium?) grease affect plastic?

Quoted message said:

Quoted message said:

For bottom brackets, we use loctite on metal threads

Do you treat all the threads or just the outer few? What Loctite
product do you use?

we treat all the threads with a medium grade loctite (242 I think)

Quoted message said:

Quoted message said:

grease on plastic.

Does plastic need anything? Does (lithium?) grease affect plastic?

grease helps keep the moisture out. i don't know much about lithium
grease...we just use the kind made for bicycle bearings (phil wood,
park, pedros, etc)

-sam

flatline said:

Good point. I wondered about PTFE tape for bottom bracket threads.
Seems it's the recommended industry practice to use grease or
anti-seize there. I believe the BB flexes and rocks with crank
rotation. PTFE is pretty thin. Will the tape be cut through and wear
out quickly in this situation?

My experience is that teflon tape is excellent for bottom bracket threads.

--

David L. Johnson

__o | Enron's slogan: Respect, Communication, Integrity, and
_`\(,_ | Excellence.
(_)/ (_) |

homer908 said:

A fellow who tested PTFE on bottom brackets told me it was good for
coarse plumbing threads but tends to get displaced on finer bicycle
threads. For bottom brackets, we use loctite on metal threads and
grease on plastic.

I vehemently disagree. For one, don't use loctite. It should not be
necessary, and is a bad idea with those fine threads, especially on an
aluminum frame. Use grease if you refuse to try teflon tape, but there is
so little to lose trying the teflon to see whether or not these wags are
right (they are not).

--

David L. Johnson

__o | Accept risk. Accept responsibility. Put a lawyer out of
_`\(,_ | business.
(_)/ (_) |

"David L. Johnson" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

homer908 said:

A fellow who tested PTFE on bottom brackets told me it was good for
coarse plumbing threads but tends to get displaced on finer bicycle
threads. For bottom brackets, we use loctite on metal threads and
grease on plastic.

I vehemently disagree. For one, don't use loctite. It should not be
necessary, and is a bad idea with those fine threads, especially on an
aluminum frame. Use grease if you refuse to try teflon tape, but
there is so little to lose trying the teflon to see whether or not
these wags are right (they are not).

Antisieze compound. IMO, it seems to say around longer than grease, that
eventually gets washed out.

--
Mike DeMicco <[email hidden]>

Quoted message said:

A fellow who tested PTFE on bottom brackets told me it was good for
coarse plumbing threads but tends to get displaced on finer bicycle
threads.

I've used teflon tape on bottom brackets for a long, long time. It
stopped the minor creaking my Cannondale was having.

It doesn't get displaced. Where would it go?

- Frank Krygowski

Mike DeMicco said:

Quoted message said:

Quoted message said:

A fellow who tested PTFE on bottom brackets told me it was good
for coarse plumbing threads but tends to get displaced on finer
bicycle threads. For bottom brackets, we use Loctite on metal
threads and grease on plastic.

Quoted message said:

Quoted message said:

I vehemently disagree. For one, don't use Loctite. It should not
be necessary, and is a bad idea with those fine threads, especially
on an aluminum frame. Use grease if you refuse to try Teflon tape,
but there is so little to lose trying the Teflon to see whether or
not these wags are right (they are not).

Quoted message said:

Anti-seize compound. IMO, it seems to say around longer than grease,
that eventually gets washed out.

Anti-seize compound isn't displaced because the active ingredient is
not a liquid as is the lubricant (oil) in greases. Anti-seize
compound contains metal flakes of a softer metal than steel, (there
are several sorts of various metal pairings) and that part remains in
the interface because it is a solid. Solids don't flow like liquids
yet they have a maximum shear strength and that is what makes these
compounds useful. Although the grease (oil) of the anti-seize
compound can be displaced, the metallic portion does not (if the
appropriate compound is used). It all boils down to fretting which in
the long run destroys interfaces, with or without anti-seize compound.

Jobst Brandt

On 3 Jan 2007 11:00:09 -0800, [email hidden] may have

Quoted message said:

I just discovered that PTFE tape is a good anti seize agent. Clean,
easy to use, cheap. Was I the only one who didn't know? (Shouts of YES!
all round the interweb)

Plumbers and mechanics, at the very least, have been aware of this for
a long time. OTOH, sometimes this property means that there is good
reason *not* to use PTFE tape in a specific application; if a fitting
is going to be subjected to occasional torsional loading, it's much
wiser to use a locking sealant instead.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Where's the hat rack said:

Quoted message said:

I just discovered that PTFE tape is a good anti seize agent.
Clean, easy to use, cheap. Was I the only one who didn't know?
(Shouts of YES! all round the interweb)

Quoted message said:

Plumbers and mechanics, at the very least, have been aware of this
for a long time. OTOH, sometimes this property means that there is
good reason *not* to use PTFE tape in a specific application; if a
fitting is going to be subjected to occasional torsional loading,
it's much wiser to use a locking sealant instead.

Teflon tape is used to seal threaded pipe joints while not hardening
as old pipe joint compound did. Anti-seize is not its primary
function and it is miserable in threads that have either radial or
axial cyclic loading. As above, torsion is especially bad. That is
not its purpose of Teflon tape.

As I said, anti-seize compound is what belongs in those threads.

Jobst Brandt

On 04 Jan 2007 05:22:47 GMT, [email hidden] may have

Quoted message said:

Where's the hat rack said:

Quoted message said:

I just discovered that PTFE tape is a good anti seize agent.
Clean, easy to use, cheap. Was I the only one who didn't know?
(Shouts of YES! all round the interweb)

Quoted message said:

Plumbers and mechanics, at the very least, have been aware of this
for a long time. OTOH, sometimes this property means that there is
good reason *not* to use PTFE tape in a specific application; if a
fitting is going to be subjected to occasional torsional loading,
it's much wiser to use a locking sealant instead.

Teflon tape is used to seal threaded pipe joints while not hardening
as old pipe joint compound did.

Correct, though in industrial environment, its propensity for
migrating under moderate pressure has caused more than one company to
issue a directive prohibiting its use on anything but low-pressure
potable water supply pipe joints.

Quoted message said:

Anti-seize is not its primary
function and it is miserable in threads that have either radial or
axial cyclic loading. As above, torsion is especially bad. That is
not its purpose of Teflon tape.

Many things are used in applications beyond their intended purposes;
sometimes they work, sometimes they don't. IME, PTFE tape is best
replaced by a more suitable material in virtually all applications,
including those for which it is nominally designed. I've had far
fewer problems with pipe joint leaks when using a good pipe sealant
compound that when using the tape...and I long ago stopped trying to
keep track of the places where I found it gumming up the works in a
place where it simply didn't belong at all. Perhaps the most
egregious instance was when I peeled a wad of it out of the terminals
of a side-post battery. It appeared that the tape had been used in an
attempt to reduce the corrosion that was resulting from acid seepage
around the post. What was achieved, of course, was non-functionality
of the connection.

Quoted message said:

As I said, anti-seize compound is what belongs in those [BB] threads.

I have no better advice to offer.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Quoted message said:

Quoted message said:

For bottom brackets, we use loctite on metal threads

Do you treat all the threads or just the outer few? What Loctite
product do you use?

Quoted message said:

grease on plastic.

Does plastic need anything? Does (lithium?) grease affect plastic?

I would not ever use loctite on a BB shell/BB cup interface. I have had
to cut too many BB cups outta frames that were not greased but
locktited. Prepped frame, grease and torque are the keys.

Werehatrack said:

On 04 Jan 2007 05:22:47 GMT, [email hidden] may have

Quoted message said:

Teflon tape is used to seal threaded pipe joints while not hardening
as old pipe joint compound did.

Correct, though in industrial environment, its propensity for
migrating under moderate pressure has caused more than one company to
issue a directive prohibiting its use on anything but low-pressure
potable water supply pipe joints.

Odd. I first learned about teflon tape when working for a hydraulics
manufacturer. In the endurance testing lab, we used it on NPT threads
subjected to 3000 psi hydraulic oil. Worked fine, as I recall.

Works fine on my bottom bracket, too.

- Frank Krygowski

Quoted message said:

Werehatrack said:

On 04 Jan 2007 05:22:47 GMT, [email hidden] may have

Quoted message said:

Teflon tape is used to seal threaded pipe joints while not hardening
as old pipe joint compound did.

Correct, though in industrial environment, its propensity for
migrating under moderate pressure has caused more than one company to
issue a directive prohibiting its use on anything but low-pressure
potable water supply pipe joints.

Odd. I first learned about teflon tape when working for a hydraulics
manufacturer. In the endurance testing lab, we used it on NPT threads
subjected to 3000 psi hydraulic oil. Worked fine, as I recall.

Works fine on my bottom bracket, too.

- Frank Krygowski

Somewhere out there there's a video of a small helix of tape being
squeezed out of a threaded joint under very high pressure.

A good pipe-thread is a metal-to-metal joint.

Quoted message said:

Quoted message said:

Werehatrack said:

On 04 Jan 2007 05:22:47 GMT, [email hidden] may have
said:

>Teflon tape is used to seal threaded pipe joints while not hardening
>as old pipe joint compound did.

Correct, though in industrial environment, its propensity for
migrating under moderate pressure has caused more than one company to
issue a directive prohibiting its use on anything but low-pressure
potable water supply pipe joints.

Odd. I first learned about teflon tape when working for a hydraulics
manufacturer. In the endurance testing lab, we used it on NPT threads
subjected to 3000 psi hydraulic oil. Worked fine, as I recall.

Works fine on my bottom bracket, too.

- Frank Krygowski

Somewhere out there there's a video of a small helix of tape being
squeezed out of a threaded joint under very high pressure.

A good pipe-thread is a metal-to-metal joint.

Dear Frank & JT,

"CAUTION: Do not use PTFE tape on hydraulic pipe connections. If a
sealant is required to ensure a leakfree joint, use "Loctite
Threadlock or a similar sealant."

--p.62, manual for a marine autopilot
http://www.raymarine.com/raymarine/SubmittedFiles/Handbooks/Autopilots/ST5000plus_stern_hydr.pdf

"Never try to ease any regulator threads with oil; do not use PTFE
tape. This advice applies to ALL gas cylinders and regulators."

--p. 19, BOC Gases pdf
b2.boc.comSAFEUNDE.PDFOpen ↗

"WARNING: Do not use PTFE tape to seal the fittings. Use a thread
sealant. We recommend Loctite 'Lock'N'Seal'."
--p. 26 another marine steering system manual
http://www.aquafax.co.uk/pdfs/04_cat.pdf

"Never use oil or grease especially on an Oxygen cylinder and do not
use PTFE tape to attempt to seal leaks."
--"THE TRANSPORT AND USE OF COMPRESSED GAS CYLINDERS" safety document
http://72.14.253.104/search?q=cache:3hbYrZwh_AwJ:www2.umist.ac.uk/matsci/depment/Safety/MMSC003-Gas%2520cylinder%2520safety.doc+%22do+not+use+ptfe+tape%22&hl=en&gl=us&ct=clnk&cd=28

And so on. Apparently, PTFE tape is a no-no for sealing high-pressure
gas or hydraulic joints.

Cheers,

Carl Fogel

Quoted message said:

Teflon tape is used to seal threaded pipe joints while not hardening
as old pipe joint compound did. Anti-seize is not its primary

Not nearly as good as hemp threads though, in central heating pipes or
city-gas[1] pipes. Unfortunately when we switched from city gas to natural
gas, we lost most of the moisture, allowing those hemp threads to dry out
and lose airtightness.

Jasper

[1] Gas manufactured by driving off the volatiles from coal, producing gas
and coke in one fell swoop. Used almost everywhere before natural gas came
along. If you see 'the gas works' on a photo, that's apparently what it
did -- that and have a couple of absolutely humongous silos that could
expand like pistons to match the continous 24/7 production rate to the
discontinuous "peak and low hour" consumption rate.

Jasper Janssen said:

Quoted message said:

Teflon tape is used to seal threaded pipe joints while not hardening
as old pipe joint compound did. Anti-seize is not its primary

Not nearly as good as hemp threads though, in central heating pipes or
city-gas[1] pipes. Unfortunately when we switched from city gas to natural
gas, we lost most of the moisture, allowing those hemp threads to dry out
and lose airtightness.

Jasper

[1] Gas manufactured by driving off the volatiles from coal, producing gas
and coke in one fell swoop. Used almost everywhere before natural gas came
along. If you see 'the gas works' on a photo, that's apparently what it
did -- that and have a couple of absolutely humongous silos that could
expand like pistons to match the continous 24/7 production rate to the
discontinuous "peak and low hour" consumption rate.

Too bad about that loss of moisture. Bummer.

There was a manufactured gas plant in my old home town Oak Park, IL from
1896-1924, at which point they created a park on the site. In 1999 they
roped the 3.5 acres off and convinced the utility company to spend
$55,000,000 removing the cancerous arsenic, benzene and polyaromatic
hydrocarbons contained in the waste coal tar, along with the top 10' of
topsoil, weighing 85,000 tons. Luckily I never played in that
particular park. Interesting discussion on wikipedia under "town gas"
anyway. I'm not sure what this has to do with that white tape I used to
erroneously wrap on my titanium pedal threads before I saw the light and
converted to anti-seize. No creaking yet, so it may be a keeper.

http://www.lib.niu.edu/ipo/2002/ip020317.html

Bill Westphal

On Sun, 07 Jan 2007 00:58:51 -0700, Bill Westphal <[email hidden]>

Quoted message said:

There was a manufactured gas plant in my old home town Oak Park, IL from
1896-1924, at which point they created a park on the site. In 1999 they

Did they move the plant elsewhere in 1924? My hometown's gas works was
operating on its site until the 50s, and stood there another decade or so
derelict. It was torn down eventually and the site became a fenced-off
jungle, with recently at the end of the 90s it finally getting cleaned up
and turned into a park. When I was growing up, it was where you illicitly
went to make things burn.

Jasper