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Science Forum Index » Chemistry Forum » How to cut flask neck?
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| DaveC |
 Posted: Sat Dec 27, 2003 12:42 pm |
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| G. R. L. Cowan |
| Posted: Sat Dec 27, 2003 12:53 pm |
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DaveC wrote:
Practise on some scrap. Scratch one side, wet the scratch,
apply tension and bending stress so the whole plane you want
the crack to propagate through has tension, and it is highest
at the scratch.
--- Graham Cowan
http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.doc --
fireproof fuel, real-car range, nuclear cachet |
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| Richard Henry |
| Posted: Sat Dec 27, 2003 12:58 pm |
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"DaveC" <me@privacy.net> wrote in message
news:0001HW.BC13049C018058C0F0080600@news.individual.net...
Quote: http://www.crscientific.com/boilingflasks.html
I want to trim the neck of this 100 ml flask down to the body, or as close
as
is practical.
How does one cut lab glass without destroying it completley?
Craft stores used to sell a device that would score a wine bottle on the
inside so that it could be broken down into drinking glasses. |
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| Bill Vajk |
| Posted: Sat Dec 27, 2003 2:20 pm |
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Richard Henry wrote:
Quote: "DaveC" <me@privacy.net> wrote in message
news:0001HW.BC13049C018058C0F0080600@news.individual.net...
http://www.crscientific.com/boilingflasks.html
I want to trim the neck of this 100 ml flask down to the body, or as close
as
is practical.
How does one cut lab glass without destroying it completley?
Craft stores used to sell a device that would score a wine bottle on the
inside so that it could be broken down into drinking glasses.
The one I have scores the outside. |
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| DaveC |
| Posted: Sat Dec 27, 2003 2:27 pm |
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On Sat, 27 Dec 2003 9:53:18 -0800, G. R. L. Cowan wrote
(in message <3FEDC70E.AEAC98FF@eagle.ca>):
Quote: Practise on some scrap.
I've got a scrap flask.
Quote: Scratch one side, wet the scratch,
apply tension and bending stress so the whole plane you want
the crack to propagate through has tension, and it is highest
at the scratch.
So just a scratch on one side of the neck with a file or such...
Wet the scratch (don't understand why, but that's not important)...
Place the back of the neck against the edge of a table (as a fulcrum)...
"Bend" the neck against the table edge...
That's it?
Wearing some gloves, I presume, would be a good idea.
Thanks,
--
DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group |
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| DaveC |
| Posted: Sat Dec 27, 2003 2:29 pm |
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On Sat, 27 Dec 2003 11:20:22 -0800, Bill Vajk wrote
(in message <WXkHb.665764$HS4.4731114@attbi_s01>):
Quote: Craft stores used to sell a device that would score a wine bottle on the
inside so that it could be broken down into drinking glasses.
The one I have scores the outside.
I can't visualize you "bending" the bottle at this point until it breaks. Do
you whack it with a small hammer, or such? Or is it really easy to break the
bottle with just "bending" force?
Thanks,
--
DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group |
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| Mark Thorson |
| Posted: Sat Dec 27, 2003 2:31 pm |
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Bill Vajk wrote:
Quote: Richard Henry wrote:
Craft stores used to sell a device that would score a wine bottle on the
inside so that it could be broken down into drinking glasses.
The one I have scores the outside.
I've used one that scores the outside. Then, you insert
a j-shaped rod through the neck of the bottle and tap
lightly on the inside surface opposite the score line.
This creates a crack along the score line. You keep
working your way around the circumference of the
bottle, until the crack goes all the way around.
My dad used a gadget he made himself. He'd
score the outside of the bottle, then wrap a piece
of resistance wire around the bottle over the
score line. He'd hook up the wire to a transformer,
and heat it up till it glowed. This would crack
the bottle along the score line in one shot. It formed
a much cleaner crack than the tapping method
described above. |
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| bob |
| Posted: Sat Dec 27, 2003 2:31 pm |
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On Sat, 27 Dec 2003 19:20:22 GMT, Bill Vajk
<bill9north@hotmail.DITCHTHIS.com> wrote:
Quote: Richard Henry wrote:
"DaveC" <me@privacy.net> wrote in message
news:0001HW.BC13049C018058C0F0080600@news.individual.net...
http://www.crscientific.com/boilingflasks.html
I want to trim the neck of this 100 ml flask down to the body, or as close
as
is practical.
How does one cut lab glass without destroying it completley?
Craft stores used to sell a device that would score a wine bottle on the
inside so that it could be broken down into drinking glasses.
The one I have scores the outside.
Aren't the edges of the glass sharp? Do you do something to smooth
them? |
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| Mark Thorson |
| Posted: Sat Dec 27, 2003 2:33 pm |
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bob wrote:
Quote: Aren't the edges of the glass sharp?
Do you do something to smooth them?
Emery paper works for this purpose. |
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| Chris Cooksey |
| Posted: Sat Dec 27, 2003 4:20 pm |
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In article <0001HW.BC131D88018630B1F0080600@news.individual.net>, DaveC
<me@privacy.net> writes
Quote: On Sat, 27 Dec 2003 11:20:22 -0800, Bill Vajk wrote
(in message <WXkHb.665764$HS4.4731114@attbi_s01>):
Craft stores used to sell a device that would score a wine bottle on the
inside so that it could be broken down into drinking glasses.
The one I have scores the outside.
I can't visualize you "bending" the bottle at this point until it breaks. Do
you whack it with a small hammer, or such? Or is it really easy to break the
bottle with just "bending" force?
Yep: if you just bend and pull away from the score mark, the two halves
just pop apart !
--
Chris Cooksey |
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| G. R. L. Cowan |
| Posted: Sat Dec 27, 2003 4:44 pm |
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Chris Cooksey wrote:
Quote:
In article <0001HW.BC131D88018630B1F0080600@news.individual.net>, DaveC
me@privacy.net> writes
On Sat, 27 Dec 2003 11:20:22 -0800, Bill Vajk wrote
(in message <WXkHb.665764$HS4.4731114@attbi_s01>):
Craft stores used to sell a device that would score a wine bottle on the
inside so that it could be broken down into drinking glasses.
The one I have scores the outside.
I can't visualize you "bending" the bottle at this point until it breaks. Do
you whack it with a small hammer, or such? Or is it really easy to break the
bottle with just "bending" force?
Yep: if you just bend and pull away from the score mark, the two halves
just pop apart !
But don't neglect the pulling.
I recall certain fractured glass rods
and the natural fracture is sigmoid.
Bending puts the side where the crack starts in tension,
and the side it would get to if it went straight in compression.
But if two regions of glass are pressing on each other,
a propagating crack won't go between them.
It instead goes some way up or down the rod
before coming straight out at the other end of the sigma.
You want an unnatural straight-through crack,
so tension must be enough that even with bending force,
there's tension from where the crack starts all the way
straight through to the far side.
--- Graham Cowan
http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.doc --
fireproof fuel, real-car range, no emissions |
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| Bill Vajk |
| Posted: Sat Dec 27, 2003 5:23 pm |
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DaveC wrote:
Quote: On Sat, 27 Dec 2003 11:20:22 -0800, Bill Vajk wrote
(in message <WXkHb.665764$HS4.4731114@attbi_s01>):
Craft stores used to sell a device that would score a wine bottle on the
inside so that it could be broken down into drinking glasses.
The one I have scores the outside.
I can't visualize you "bending" the bottle at this point until it breaks. Do
you whack it with a small hammer, or such? Or is it really easy to break the
bottle with just "bending" force?
Thanks,
Light tapping on the score. Sometimes I use a pair of pliers,
ot a tack hammer, or whatever is at hand. All it takes is
localized stress with a well established line for relieving
it. Plink! |
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| Bill Vajk |
| Posted: Sat Dec 27, 2003 5:30 pm |
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bob wrote:
Quote: On Sat, 27 Dec 2003 19:20:22 GMT, Bill Vajk
bill9north@hotmail.DITCHTHIS.com> wrote:
Richard Henry wrote:
"DaveC" <me@privacy.net> wrote in message
news:0001HW.BC13049C018058C0F0080600@news.individual.net...
http://www.crscientific.com/boilingflasks.html
I want to trim the neck of this 100 ml flask down to the body, or as close
as
is practical.
How does one cut lab glass without destroying it completley?
Craft stores used to sell a device that would score a wine bottle on the
inside so that it could be broken down into drinking glasses.
The one I have scores the outside.
Aren't the edges of the glass sharp?
Yep.
Quote: Do you do something to smooth them?
Usually not. But then I don't drink out of them. They're
good for other uses women generally put them to, like
candles for example.
I have been known to carefully heat the edge with a flame
but that's pretty risky unless you stress relieve the glass
first (long term high temp bake, essentially getting close
to commercial grade tempered glass.) |
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| Mike Painter |
| Posted: Sat Dec 27, 2003 7:08 pm |
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"DaveC" <me@privacy.net> wrote in message
news:0001HW.BC13049C018058C0F0080600@news.individual.net...
Quote: http://www.crscientific.com/boilingflasks.html
I want to trim the neck of this 100 ml flask down to the body, or as close
as
is practical.
How does one cut lab glass without destroying it completley?
A Google on bottle cutter brings a lot of hits.
http://www.glassmart.com/ebc.asp
has a kit for wine bottles and instructions.
I remember something similar from the 60's. |
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| Teel Adams |
| Posted: Sat Dec 27, 2003 7:41 pm |
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Ya know, I'm going to throw something out just to be contrary. I have an
old farm house, and the concept of a square corner, uniform studs, tape
measures or blueprints do not appear to have been invented when the house
was constructed.
So, what is the point? For much of my tile work on the kitchen and
bathroom, and I know this is the stupid and slow way to do this, I had a
homemade table saw that I got at auction, outfitted with a variety of
grinding wheels. Both synthetic ruby/saphire, corrundium? something like
that, and the diamond blade and wheel work pretty good. I even played
around with doing some glass work over the years. You'd need to have water
cooling, make your cut close to where you wanted to be, and slowly grind
down to the position that you want. Well, it might take a number of trys to
get the technique down.
I cut a nominal 3" square hole out of a four inch ceramic tile this way.
Oh, come to think of it, flasks are much more expensive than tiles.
"Mike Painter" <mdotpainter@att.net> wrote in message
news:iapHb.248146$Ec1.8624265@bgtnsc05-news.ops.worldnet.att.net...
Quote:
"DaveC" <me@privacy.net> wrote in message
news:0001HW.BC13049C018058C0F0080600@news.individual.net...
http://www.crscientific.com/boilingflasks.html
I want to trim the neck of this 100 ml flask down to the body, or as
close
as
is practical.
How does one cut lab glass without destroying it completley?
A Google on bottle cutter brings a lot of hits.
http://www.glassmart.com/ebc.asp
has a kit for wine bottles and instructions.
I remember something similar from the 60's.
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