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?

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...

"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.

On Sat, 27 Dec 2003 9:53:18 -0800, G. R. L. Cowan wrote
(in message <3FEDC70E.AEAC98FF@eagle.ca>):

Practise on some scrap.

I've got a scrap flask.

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)...
Wetness changes the surface Gibbs free energy. While spit helps there are

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,

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? Do you do something to smooth
them?

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?

DaveC <me@privacy.net> wrote:



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?



Be aware that making a square cut on glass tubing become exponentially
more difficult as the diameter of the tubing increases. I would
personally not attempt the "scratch-then-bend-and-pull" method for
anything larger than about 1 cm diameter (unless I was willing to put
up with a lot of trashed pieces).

A diamond glass-cutting saw does the best job. You will end up with a
perfectly square cut, with the cut surface having a frosted appearance
and a finish which is generally not sharp enough to be dangerous. But
few people have access to diamond saws.

Other than that, the best method that I've seen for cutting
large-diameter tubing starts with a small scratch which is then
propagated as a crack, using thermal expansion, around the diameter of
the tubing. The thermal expansion can be induced with a hot wire, as
others have described, or by other hot objects. The time-honored
glassblower's trick is to heat a glass rod until molten, then press
the molten blob against one end of the scratch. This will cause a
crack to begin, and one can then lead the crack around the diameter by
successive applications of the hot glass rod. This is easier to do
than to describe. Done properly it works quite well.

Steve Turner

Real address contains worldnet instead of spamnet

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?

Thanks,
--
DaveC

A diamond glass-cutting saw does the best job. You will end up with a
perfectly square cut, with the cut surface having a frosted appearance
and a finish which is generally not sharp enough to be dangerous. But
few people have access to diamond saws.

On Sat, 27 Dec 2003 20:01:07 -0800, Steve Turner wrote
(in message <7khsuv0t5nc6heeguaruehq28orb3jci5p@4ax.com>):
A diamond glass-cutting saw does the best job. You will end up with a
perfectly square cut, with the cut surface having a frosted appearance
and a finish which is generally not sharp enough to be dangerous. But
few people have access to diamond saws.

Where in a a city would I look for a business that has access to a diamond
saw? Jewelers? Help me out, here...

On Sat, 27 Dec 2003 20:01:07 -0800, Steve Turner wrote
(in message <7khsuv0t5nc6heeguaruehq28orb3jci5p@4ax.com>):

A diamond glass-cutting saw does the best job. You will end up with a
perfectly square cut, with the cut surface having a frosted appearance
and a finish which is generally not sharp enough to be dangerous. But
few people have access to diamond saws.

Where in a a city would I look for a business that has access to a diamond
saw? Jewelers? Help me out, here...

On Sat, 27 Dec 2003 20:01:07 -0800, Steve Turner wrote
(in message <7khsuv0t5nc6heeguaruehq28orb3jci5p@4ax.com>):



A diamond glass-cutting saw does the best job. You will end up with a
perfectly square cut, with the cut surface having a frosted appearance
and a finish which is generally not sharp enough to be dangerous. But
few people have access to diamond saws.



Where in a a city would I look for a business that has access to a diamond
saw? Jewelers? Help me out, here...

DaveC wrote:

On Sat, 27 Dec 2003 20:01:07 -0800, Steve Turner wrote
(in message <7khsuv0t5nc6heeguaruehq28orb3jci5p@4ax.com>):



A diamond glass-cutting saw does the best job. You will end up with a
perfectly square cut, with the cut surface having a frosted appearance
and a finish which is generally not sharp enough to be dangerous. But
few people have access to diamond saws.



Where in a a city would I look for a business that has access to a
diamond
saw? Jewelers? Help me out, here...


Google any nearby college or university chemistry department and check
if they have a glassblowing shop. Wander in and ask if they can take a
small job. Hint: Glassblowers like to talk, and will work faster and
better for you if you spend some time talking with them.

josh halpern

"Josh Halpern" <j.halpern@incoming.verizon.net> wrote in message
news:uaGHb.1110$f3.454@nwrddc01.gnilink.net...


DaveC wrote:

On Sat, 27 Dec 2003 20:01:07 -0800, Steve Turner wrote
(in message <7khsuv0t5nc6heeguaruehq28orb3jci5p@4ax.com>):



A diamond glass-cutting saw does the best job. You will end up with a
perfectly square cut, with the cut surface having a frosted appearance
and a finish which is generally not sharp enough to be dangerous. But
few people have access to diamond saws.



Where in a a city would I look for a business that has access to a
diamond
saw? Jewelers? Help me out, here...


Google any nearby college or university chemistry department and check
if they have a glassblowing shop. Wander in and ask if they can take a
small job. Hint: Glassblowers like to talk, and will work faster and
better for you if you spend some time talking with them.

josh halpern

"Glassblowers like to talk..." Yeah but they are all blowhards.

From: Josh Halpern j.halpern@incoming.verizon.net

Hint: Glassblowers like to talk, and will work faster and
better for you if you spend some time talking with them.

From: Josh Halpern j.halpern@incoming.verizon.net

Hint: Glassblowers like to talk, and will work faster and
better for you if you spend some time talking with them.

It's becominga lost art ... back in the late sixties we had
plenty of meetings with those at [snip]