laminated glass tubes

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I make display glass tubes with high pressure content (up to 200 bar).
To protect the tubes from damage and to protect the spectators from
shrapnel in case of an explosion I try to make a protective cover.

Previously I used polycarbonate tube which is strong enough, but is easy
to scratch and may turn brittle eventually. So I'm looking for something
that will last 100+ years. I try to make laminated glass tubes. Filling
the 1-3mm gap between concentric glass tubes with polyester produced
bubbles as the polyester shrunk when it set.

Can you recommend other materials to fill the gap? They should ...

last very long (100+ years)
excellent optical clarity
The temperature range might be -40 C (cold weather) to 70 C (inside a
car in full sun).

Preferably they should be...

low viscosity so I can get them in the gap
index of refraction and thermal expansion similar to borosilicate glass
- 1,52 and 5 * 10^?6
not too expensive

Currently I'm thinking of ...

1) hydrocarbon gel such as in gel candles. It might be fluid enough so
it will not detach from the glass surfaces when its volume grows and
shrinks with varying temperature. But I'm afraid the hydrocarbons might

2) crystal clear polyurethane resin.

3) crystal clear silicone or modified silicone/silane (MS-polymer)

4) Other crystal clear sealants

Actually just a simple (viscous) liquid (glycerol) might do the job, if
it could be sealed in the gap reliably.

Thanks, Bernhard

Re: laminated glass tubes

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Why not make samples and test them by breaking them at 200 bar
and seeing what the result is?

Any restriction on thickness (bullet -proof glass)?
Any restriction on wire?

Re: laminated glass tubes
Androcles wrote:
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I do make explosion tests with display tubes filled to higher than
normal pressure. But acquiring the materials costs money and making the
pressure and protective tubes is a lot of work so I try to pick the
ideal materials at first.

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Not unless they remain practical. I'm currently thinking of 60 mm total
outer diameter with 7 mm wall thickness for the outer tube, 1-3 mm gap
material and 2 mm inner tube of the protective tube. That's 10-12 mm
total wall thickness of the protective tube. Length is 20-25 cm.

The pressure tube within the protective tube is 10 mm OD.

But I could not find bullet proof glass *tubes*. I did find laminated
glass tubes intended as pillars in building construction. However, they
cost near 100 Euro per 25cm piece.

I thought of using laminated glass panes, which are easier to make. But
a tube looks much better than a cuboid. Also how do I join the panes so
they will not open at the edges when the pressure tube explodes.

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The purpose is to watch the pressure tube in detail. So I will try
without wires.


Re: laminated glass tubes
Bernhard Kuemel wrote:
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What about a box that is metal on all sides
but one, the latter being the laminated plate

Or maybe metal on all sides with a video
camera and lamp inside with the tube.

Re: laminated glass tubes
Mark Thorson wrote:
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The cute part is seeing critical point opalescence for CO2, N2O, SF6,
CF3Br, propane, CCl2F2, CH2F2, ethylene, C2F6, etc.  Gotta have a
through-sight path.

Uncle Al
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Re: laminated glass tubes
Uncle Al wrote:
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Why do people use CO2?  Wouldn't one of those
other molecules be a lot safer?  What would be
the safest candidate?

Re: laminated glass tubes
Mark Thorson wrote:
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CO2 is cheap and available. It has an excellent critical temperature.
You can make it critical with body heat or other low power heating and
cool it below critical with ambient temperature. It is non toxic, non
ozone depleting (influences availability). Its (super)critical pressure
is low enough so it can be contained in glass tubes.

CClF3 has great critical data (29C, 39 bar), but it is ozone depleting
and hard to get. C2F6 has even lower pc (33 bar), but Tc is silghtly too
low (19 C) so it would have to be cooled to go subcritical. It's
expensive (compared to CO2) and I would have to buy or rent a pressure
bottle. And even at 33 bar (or more if supercritical) a protective case
is very preferable. So I just use CO2. Supercritical CO2 is also used
industrially and so is particularly interesting for people to watch.

Ohh, BTW, Helium would be the safest candidate: 2.3 bar, but at 5 K. :)
Or something like C7F16 with 16 bar and 202 C in an oil bath might be
an option.


Re: laminated glass tubes
On 23 ??????, 13:28, Bernhard Kuemel <bernh..> wrote:
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I am happy to be a member of this group and I consider you my friends.
As a friend , I like to share with you some thoughts that I believe
will be useful for your life.

Women In Islam

Sexual Politics

Imagine this scenario, for it is real: two antagonists locked in a
grim power struggle. And another: two or more other competitors,
rivals in a race for high stakes, a race to determine the course of
their entire life. At race?s end, the prizes for winning include
compliments, telling glances, and First Prize, a wedding ring.
Unwanted "prizes" along the way may include physical assault,
countless violations of body and soul. The protagonists of these
scenarios are all around us; they are modern man and modern woman, and
woman vs. woman. From time immemorial, against this harsh horizon of
human relations, the "battle of the sexes" has raged. But never has
"Sexual Politics been so virulent as today. Feminism becomes
polarization along gender barriers. To offset increased competition
for a mate, extreme nudity splashes itself unchecked. Fear and
suspicion on both sides lurk; commitments are tepid, or all too
Sexual Balance

Now conjure this, from the Qur?an, the Book of the Revelation sent  
guide the affairs of mankind; It comes from Allah (SWT ? the Deity;
One, Only) to us, His creatures: "Your wives are a garment to you, and
you to them. " (Surah 2:187). As close as the skin to a garment, as
essential as the covering layer which envelops andd protects us from
heat and cold, man and wife are the two halves of humanity coming
together in balanced, mutual protection and care. This is the other
veil, the deeper veil, the real covering and garment of ISLAM. In days
remarkably similar to ours, a new path was taught: the path of
enduring partnership and cooperation in human affairs, to level the
exhausting shifting sands of competition and suspicion. This path was
AL-ISLAM. Islam means the deep submission to God alone, Allah (SWT  
The One, The Deity, "Eloh" of the Hebrews). Fittingly, the name of
this grace-filled, all-encompassing path of balance and harmony for
mankind was derived from "Salaam," the Arabic word for peace.

"For Islam is the religion before Allah" (Surah 3:19) ISLAM was not a
new religion, "another" religion; it is the same universal truth that
God has enjoined upon humanity throughout the ages, in its final, most
comprehensive exposition. 1400 years after its Revelation, it stands
as pristine, and as beneficial, as it was on the day Allah (SWT) first
granted it: in a time of upheaval, in a world of unraveling values, in
a society confused and chaotic much like ours. There Allah (SWT) chose
His last Prophet, the Seal of the Messengers, the Mercy for all
mankind. He was an upright, kind and honorable man living in seventh-
century Arabia, at the very fringes of the civilized world. And when
first Muhammad, in his fortieth year, peace be upon him, heard the
Word of Allah (SWT), he was shaken and he was stunned. And he turned
to a woman, his wife Khadija, for counsel: am I mad? he asked. This
true companion knew better. Go, she said, and serve Allah (SWT). The
Revelation of Islam was gathered over 23 often perilous years, in the
Book of Recitation, the Qur?an. Today, 1/5th of humanity is Muslim,
(those who surrender to Allah?s, SWT, Will) and millions more (wome
in the forefront) are heeding its voice. For this Voice speaks with
irresistible appeal, of the equitable design for living for all human
beings, beyond race, beyond gender: the sheltering peace.


Islam is freedom; it upholds free will and encourages rational
thought; it recognizes only that virtue or sin which an individual
earns through free action and choice. Within its parameters is a code
of behavior, a complete social pattern for man and for woman, that
looks out to the whole of life through the harmony of a balanced
scale. In this system, based on natural law and innate reason, (the
Knowing System of the Creator Himself ? SWT), cooperation is the
standard criterion. Muslims are brothers and sisters in the family of
mankind brethren all under Islam, in the sweet surrender of obedience
and worship to Allah (SWT), Unique and One (Tawhid). Each Muslim, man
or woman, chooses to be a Muslim. Each Muslim is ultimately
accountable for his and her actions to Allah (SWT) alone. Allah (SWT)
will call us all to account on the Day of Reckoning. How easy it
becomes, then, to be truly free. For the vain idols of stone, the
enslaving tyrants of greed, of lust, of ambition, of public opinion
crumble to naught. Freedom from the tyranny of man and man-made
conceits: Islam liberates


Not one verse in the whole of the Qur?an speaks injustice Not one w
says, men and women are not equal. Everywhere, the Book of Nature and
Creation tells us: equality under God is the only criterion. Under God
in sincere worship, man and woman stand in parity. But this Book is
truth; truth does not shy away from our most basic, indisputable
biological differences. Male and female, quite simply, have distinct
and complementary roles to fill, equally vital for the sustenance of
life. Everywhere, the Qur?an reminds us of the mutual rights humans
owe to one another, in the balance of our relations. "O men! Fear your
Lord Who created you from a single being and out of it created its
mate; and out of the two spread many men and women. Fear Allah in
Whose name you demand your rights (of one another) and heed the ties
of relationships. " (Surah 4:1) In a time when most women were common
chattel, the teachings of the Qur?an and the practices (Sunnah) of
Muhammad, the Messenger(pbuh), firmly restored to them status, both
legal and social; and dignity as individuals; cemented their right to
wealth and property, to inheritance, to education. In Muhammad (pbuh),
women found the champion to uphold their rights, merciful,
sympathetic, unwavering in his support: women flocked to his call.
Budding Islam grew strong on the depth of their staunch belief. In a
day of social anarchy, Islam reintroduced structure end the natural
order. For it is the stable bond of the family unit that elevates man
from beast. It is its strong foundation, built on understanding and
collaboration, which ripples outward in concentric circles to the vast
social network. It is here that peace and freedom begin. Islam

 Natural Humanism

Your body has rights upon you, said the Prophet of Islam. By this was
meant a healthy, clean, Intelligent respect for the body and its
needs. Personal hygiene is one of Islam?s most basic requirements
Pleasing and discrete elegance is smiled upon in Islam, the world?s
great Civilization of Refinement, in body and soul. And the Prophet
said: "God Himself is graceful and elegance pleases Him." The Islamic
way does not want mankind shut up unnaturally in towers of ivory, to
ruminate endlessly in ascetic withdrawal from fellow begins. Islam is
inclusive dynamism; Useful and graceful action; Improvement and
betterment. Nor does it deny or demean the natural sex drive. On the
contrary, it elevates and liberates it, channeling it for a peaceful,
healthy society: the hectic waves of seduction, rivalry, the "theft"
of physical or mental integrity are banished. Within the REAL
partnership of matrimony, the joining of husband and wife is
legitimized: here sex is no sin, but a form of natural worship. The
Qur?an itself speaks of sexual relations between man and wife, simp
and direct; it teaches the striving toward harmony, the need for trust
and confidence between husband and wife, between life partners, as it
does between all human beings (Surah 66). Does the nurturer not need
nurturing too? The biological imperatives, Islam meets squarely, head-
on, with no coyness; for indeed Allah (SWT) created us so. Islam
addresses the differing needs of man and woman comprehensively. The
need of woman, in child bearing years, feminism not withstanding, is
sustenance and security. A pregnant woman requires care; a nursing
mother and infant require protection; a wife, mother, sister require
respect: these are their rights. Equal rights, in proportioned
measure: the way of Islam is honest and clear-sighted. To safeguard
the one from the oversights of the other; to remind the one of the
requirements of the other the balanced checks of Islam work in supreme
rationality: "Men are the protectors and maintainers of women, because
Allah has made one of them stronger than the other, and because they
spend out of their possessions (to support them)." (Surah 4: 34) Women
have the same rights as the husbands have on them. But man is the
burden-carrying partner; with the weight of duty and responsibility,
comes a measure of fair recognition "But men are a degree above them
(women)." (Surah 2:228) These are the basic injunctions of Islam
concerning women. They revolve around the rights of women, not their
restrictions. Injunctions placing restrictions on women in the Qur?
emerge chiefly in connection to the greater curbs placed on men. For
male lust, that primary, but blindest of drives, is not allowed to
become the driving force of society. Thus the Qur?anic injunctions
recommend modesty, for both men and women. (24:31; 33:35) Where the
parade of enticement and seduction prevails, Islam upholds the
standard of straight forward human dealings, inner mettle to inner
mettle. Sex and beauty stay at home; neither commodity nor potential
incentive in wider social relations, their power is curtailed to
strangers, enhanced to the bonded partner. Where promiscuity runs
rampant, Islam builds a society where children know their fathers, and
fathers are responsible for their wives and children. By severing the
loose ties of lust, Islam restores the lasting ties of partnership.
Where the sexual society objectifies, Islam humanizes.

 Hijab, Veil of Pride

"Let them wear their head-coverings over their bosoms" (Surah 24:31;
33:59). It is the minimum standard of decency. No mention of face
covering, in fact; sexual politics of individual men have seen to
that. A Muslim woman is told: cover your nakedness, do not play with
femininity as a commodity. Be proud and save your intimate best for
the one who stands by you in times good and bad. Speak loud and clear,
the game-and-promise bedroom voice does not belong on the streets,
(Surah 33:32); Walk firm and tall: the swaying, jingling advertisement
of body carries a "for sale" sign on it (Surah 24:31). The Qur?an
seeks clarity of heart and intention; Its injunctions address the
deception inherent in teasing and seduction, their signal or their
unintentional message. Hijab is first a reminder far the soul, an
inner code and standard, and only second a physical statement. Indeed
the head-to-toe cloak (chador) is by no means unique to Islam; but a
universal, spontaneous woman?s choice throughout time, the dress of
high-born Roman and Byzantine ladies for centuries to indicate their
elevated social status, set apart, "protected" from the laboring
throng. In the Qur?an, verses referring to the veil come in the
context of the early struggles of nascent Islam, when false believers
were infiltrating the infant Muslim community: Muslim ladies would be
recognized at once, wearing a pragmatic veil of conduct affirming
their belief in the Creator?s (SWT) laws. Modesty of dress
externalizes moderation of behavior: the inner hijab, the moral
affirmation of the bounds of decency, honesty, self-respect, honor,
made visible. The veil continues to offer recognition and freedom to
woman in many ways: it is a signal sent out which demands respect, and
receives it in return. Thus did Allah (SWT) intend (Surah 33:59).

The Harem

"Swathed in their veil, locked away": yet this popular image of
extremes has no place in Islam. It is born under specific skies, in
cultural imposition, solidified in misconception, perpetuated in the
rigidity of the narrow-minded or the misguided. The severe segregation
of the sexes is not a Qur?anic injunction. A Muslim woman is given
freedom of thought at all times. And that same intrinsic freedom of
action which does not lead to disharmony, in exactly the same manner
as a Muslim man. Islam does favor the inherent, the natural division
of life-spheres. A woman?s familial duty is foremost, her natural
environment is the home. To those who cry, "Sexism," a word of
reminder, and some facts. A woman will know different spans in one
single month; medical science has only now begun to concede the often
drastic influence of very real hormonal fluctuations in a woman?s
biology. The interplay of hormones and emotions is no Sexist Myth. It
is Fact. By the same token, throughout Islamic history, women who,
through their talent must rise in the larger society, have risen. In
the time of Ignorance (Jahiliyah), the Message of Islam came to
rectify rampant polygamy. The criterion, as always, balance and
fairness. In cases a man took more than one partner, it should be done
legitimately, within the norms of fair dealing. No "Second class"
categories of relationships. No one-night stand: a real commitment in
marriage. Islam never overlooks the greater social stability and
justice. It will regulate, in its omniscience, all potential forces at
work in the social In point of fact, the lifelong and monogamous bond
of marriage is the actual Muslim . The partnership endures.


Where it does not, despite the best intentions, here too, naturalness
reigns. Divorce is the most disliked of all lawful things, the Prophet
said. Prevention is the priority. But when the life of the couple has
grown destructive and counterproductive the Qur?an sets strict
guidelines, to forestall haste and whim; terms of transition (Iddat)
and reasonable waiting periods ? usually of four months ? h
ave been
enjoined, long enough for tempers to cool, for a pregnancy to reveal
itself, for circumstances to change or solidify. Divorce can be
instigated by husband or wife (Talaq and Khula), and by mutual consent
(Mubara?ah). No Muslim girl can be forced to marry against her will
When estrangement and alienation set in (Ila; Surah 2:226), the
partners are directed to bridge their gap within a reasonable period
of time, before that point of no return. For Allah (SWT) understands
and eases the frailty of humans.

Within The Sheltering Peace

This, then, is the religion of reason, the religion of balance, the
religion of fairness, the religion of peace. This is Islam. Look
around you, across the street, around the world: you will see Muslim
women choosing the veil of their own free will. For they recognize it
for what it was enjoined, an emancipation and a liberation. The
merchandising of the human being profits only that ever-voracious
corporate bottom line. Hijab is a woman?s statement, of transcendin
the often-abused power of men over their lives. It is a statement of
understanding the real meaning within the Qur?an. It is intrinsic
dignity, unadorned and straightforward, for all: and that is the
Islamic way. Today, women are tired of selling themselves short.
Selling their "assets" on a false stage, where plastic bodies and
fashion kings may dictate the shape of a life and appearances have
taken on the functions of one?s very soul. Hail the freedom of the
"liberated woman," unhinged from the trusting partnership: free to
face man-the-enemy, rape, spouse abuse, abandonment, free to starve
herself in the mating game ? Starve in the rat race. Her hard-won
rights; her pyrrhic victory. Now imagine a world where women are the
corer of men and men, their garment and covering. Imagine a world
where merit and strength of character replace the transient, the
doomed race after fading beauty; where the good become beautiful and
the beautiful, good. The Prophet once said, "God does not judge
according to your bodies and appearances but scans your hearts and
looks into your deeds." "And on of [Allah's] signs is that He created
mates you from yourselves, that you may find rest them, and between
you He put love and compassion." (Surah 30:21) Imagine this world
where companionship , this sheltering cloak for man and for woman.
Imagine such a world, and you can enter it. This is the world of

For more information about Islam

Contact Us At

Re: laminated glass tubes
On Sun, 27 Dec 2009 12:39:00 -0800 (PST), iman way wrote:
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With friends like that, who needs Dennis?

Re: laminated glass tubes

'Ron Parker[_2_ Wrote:
> ;849567']On Sun, 27 Dec 2009 12:39:00 -0800 (PST), iman way wrote:-

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> friends.

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Haha! Good question.


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