Glassblowing and Glass Production

There are several methods of making glass. One of these is glassblowing. Glassblowing uses air to inflate molten glass into various shapes. This is sometimes done with tubes and a person blowing into it. On a broader scale, this is sometimes done by machine. Glass can also be created through molds, casts, or rolling.

314 Questions
Glassblowing and Glass Production

How do you blow glass?

This information on blowing glass is taken direct from WikiHow:

Glassblowing is the process of creating artistic glass works through the manipulation of molten glass. This style of glassblowing is also called off-hand or furnace work. Off-hand glassblowing requires an extensive collection of equipment and tools.


  • Gather - Collecting glass from the furnace; the closest analogy to gathering is turning caramel onto an apple.
  • Marver - Shaping the glass on a steel table into an even, on-center cylinder.
  • Cap - Blow into the pipe and cover the hole with your thumb to trap air inside the pipe. The bubble will begin to inflate.
  • Gather again - Collect more glass around the bubble.
  • Shape and Inflate the form
  • Add a Neck-Line
  • Finish the shape and flatten the bottom.
  • Tranfer the piece onto a punty for finishing the top part.
  • Heat the lip and flare open.
  • Knock the piece off the punty and put into an annealer for slow cooling.

Here are more opinions and answers from other Wiki contributors:

  • The two URLs linked below have lots of information about glass blowing.
Glassblowing and Glass Production

Whats the difference between crystal and glass... as in crystal versus glass champagne flutes... I know glass is a viscous liquid but what is crystal?

Crystal is defined legally by a UK British Standard BS 3828 of 1973 and the EU Crystal Glass products directive 69/493 EEC of the 19th March 2002, Gazette No 24700 . The Refractive Index by UK and EU law, must be not less than 1.520, and the density must be of at least 2.54 g/cm2. If lead is present, to be called "Crystal Glass" it must contain 10% at least of zinc, barium, or potash, alone, or together. (In the USA, only 1% is needed, which would easily be considered just plain glass by the UK.) Only Lead crystal, ( or Full Lead Crystal with over 30% lead) contains lead or other materials which modify the characteristics of the material. The same is true for other types of glass where the refractive index is changed by inclusion of other materials to make camera lenses etc. "Lead crystal" was a British invention discovered by George Ravenscroft and registered on the 16th May 1667, and financed by the Worshipful Company of Glass Sellers of London.

The addition of up to 30% lead oxide, ( though most manufacturers are reducing it to 24%, the legal minimum to be called lead crystal ), gives crystal glass a high index of refraction which makes it sparkle when cut at sharp angles, is softer to cut, and gives the glass a distinctive long lasting ringing tone when it is struck gently with a hard object like a fingernail. The lead may under very extreme conditions leach out into acidic beverages, like white wine or orange juice ( if stored over night in a fridge for instance). The glass is also more fragile and subject to temperature shock: Crystal glass will often break when cold water is poured into a hot glass or vice versa.

Glass is a liquid in the sense that it does indeed flow, but it flows over an extensive period of time. The difference between a crystal and glass, is that a crystal has a homogenous solid formed by a repeating, three-dimensional pattern of atoms, ions, or molecules and having fixed distances between constituent parts. Glass on the other hand, has molecules that are disordered but are rigidly bound.

Glassblowing and Glass Production

What is glass made of?

The ordinary glass is a mixture of sodium silicate, calcium silicate and Silicon dioxide, Na2SiO3.CaSiO3.4SiO2
There isn't just one ingredient used in glass, and there are different fusions of minerals to make it as well. Check out this paragraph, it tells of a few different types of glass that we use today.

From the wikipedia site:

Pure silica (SiO2) has a "glass melting point"- at a viscosity of 10 Pa·s (100 P)- of over 2300 °C (4200 °F). While pure silica can be made into glass for special applications (see fused quartz), other substances are added to common glass to simplify processing. One is sodium carbonate (Na2CO3), which lowers the melting point to about 1500 °C (2700 °F) in soda-lime glass; "soda" refers to the original source of sodium carbonate in the soda ash obtained from certain plants. However, the soda makes the glass water soluble, which is usually undesirable, so lime (calcium oxide (CaO), generally obtained from limestone), some magnesium oxide (MgO) and aluminum oxide are added to provide for a better chemical durability. The resulting glass contains about 70 to 74 percent silica by weight and is called a soda-lime glass.[8] Soda-lime glasses account for about 90 percent of manufactured glass.

As well as soda and lime, most common glass has other ingredients added to change its properties. Lead glass, such as lead crystal or flint glass, is more 'brilliant' because the increased refractive index causes noticeably more "sparkles", while boron may be added to change the thermal and electrical properties, as in Pyrex. Adding barium also increases the refractive index. Thorium oxide gives glass a high refractive index and low dispersion, and was formerly used in producing high-quality lenses, but due to its radioactivity has been replaced by lanthanum oxide in modern eye glasses. Large amounts of iron are used in glass that absorbs infrared energy, such as heat absorbing filters for movie projectors, while cerium(IV) oxide can be used for glass that absorbs UV wavelengths (biologically damaging ionizing radiation).

Two other common glass ingredients are calumite (an iron industry by-product) and "cullet" (recycled glass). The recycled glass saves on raw materials and energy. However, impurities in the cullet can lead to product and equipment failure.

Finally, fining agents such as sodium sulfate, sodium chloride, or antimony oxide are added to reduce the bubble content in the glass.[8] Glass batch calculation is the method by which the correct raw material mixture is determined to achieve the desired glass composition.

Sand mostly.
glass is made from sand which they heat to make it transparent....... also right now the glass from anything in melting but so slowly that it will take about over 1 million years for it shrink considerably. sorry but i don't why is is made out of that. probably because sand is a solid and you can melt it to make it transparent.
it is made out of melted sand which includes ionic compounds that form lattices, this is what makes glass strong.

Glassblowing and Glass Production

Refining agent Quantity in borosilicate glasses?


Glassblowing and Glass Production

How do you make glass?

Glass is made from melting silica or sand (Silicon Dioxide DiO2) at extremely high temperatures. SiO2 in its crystalline form is known as quartz.

The main ingredient in glass is therefore quartz (as washed sand) mixed with a little sodium oxide Na2O and calcium oxide (CaO) or quicklime. These ingredients are mixed together and placed in a furnace until they all form a melt. The melt is glass.

Other additives can be added to the mix to make specialized glasses.

Glassblowing and Glass Production

Does glass expire?


Glassblowing and Glass Production

Did the Phoenicians make glass blowing?


Illegal Drugs
Glassblowing and Glass Production

Is thick glass good for a bong or not?

there is no difference between a thick glass bong and a thin glass bong except i guess the thing breakes easier

Glassblowing and Glass Production

Can glass be sprayed to get tempered glass?

Um NO you temper glass the same as you temper any thing else. You have to heat it up. it cant be cut after it has been temoerd either.

Cross section of glass has two areas, compressive strength area and tensile strength area. When glass is heated above 600 degree and fast cooled, the compressive strength area expands. Since glass has more compressive strength than tensile strength, it becomes difficult to break it. Tempered glass, especially toughened glasses are 4 to 5 times stronger than normal glass. These glasses break into small circular fragments. Normal glass breaks into sharp pieces and is a safety hazard. You may also refer this link for mare on tempered glass -

Plastics and Polymers
Glassblowing and Glass Production

Is Perspex denser than glass?

No, glass is denser than Perspex - aka Poly(methyl methacrylate), aka PMMA.

Perspex has an average density of 1.18 g/cm3.

The density of glass ranges between 2.4 g/cm3 to 2.8 g/cm3. The density of window glass is between 2.47 g/cm3 and 2.56 g/cm3. The glass in a vehicle headlight falls with the range of 2.47 g/cm3 and 2.63 g/cm3 .

Elements and Compounds
Glassblowing and Glass Production

Is glass a compound or an element or a mixture?

Glass is a homogeneous mixture.

Weight and Mass
Glassblowing and Glass Production

How much does 'glass' weigh?

1/4" plate glass weighs 3.28 lbs/SF.

Glassblowing and Glass Production

When did glass blowing start?

It started in the Late-Third or Early-Second Millennium B.C., the actual "blowing" of glass using a tube did not occur until sometime in the First century BC.

Glassblowing and Glass Production

If a hot piece of thick glass is clipped in cold waterit breaks.Give reason?

The edges of the thick glass will cool faster than the center portion since the glass has low thermal conductivity. This produces a thermal gradient in the glass putting the outside edges in a state of tension stress. Glass fails in tension at a low value if any flaw exists on the edge surface.

Elements and Compounds
Glassblowing and Glass Production

How many different kinds of atom are in glass?

Some types of glass:

  • Soda glass - silicon, oxygen, sodium, calcium
  • Leaded glass - silicon, oxygen, lead, calcium
  • etc.
Many types of glass are contaminated with iron, which turns them brown. To solve this issue a "bleaching agent" is added to the glass, a few of these are: arsenic, manganese, boron. Glass containing manganese as the "bleaching agent" on extended exposure to sunlight eventually turns purple and is now a valued collectable as it is no longer made.

Stained glass can have almost any metallic element added to get the desired color.

Glassblowing and Glass Production

What are the special properties of laboratory glassware and plastics?

Special laboratory glassware are heat resistant and chemical resistant.

Glassblowing and Glass Production

Is glass absorbent?


Glassblowing and Glass Production

How do you melt glass with a blow tourch?

It depends on the type of glass, size, and how hot your torch gets. some glass melts at a 105 degrees fahrenheit. also some melts at an hire temperature than some, and it might take a while before it melts.

Glassblowing and Glass Production

What are the tools used in glass blowing?

Some tools they used were:

  • Battledore - a flat wooden paddle used to shape molten glass objects
  • Blowpipe - a long, hollow, rod that shaped glass objects
  • Caliper - used to measure the size of a molten glass object
  • Crucible - a fire-resistant clay pot in which glassmaking objects were melted
  • Lehr - a special oven used to strengthen the glassware
  • Pincers - pliers used to stretch and squeeze glass
  • Pontil - a long metal rod connected to a molten glass object to help hold it
  • Pucellas - tongs used to twist and stretch a molten glass object
  • Shears - scissors for cutting and trimming a molten glass object
  • Pliers

These tools are what you would see when you walk in a glassblowers workshop. These tools are the main tools.

Glassblowing and Glass Production

Why is glass blowing important in colonial life?

Glass blowing was important in colonial life because in Jamestown's first glasshouse, they were able to make glass bottles and ship them cheaply back to England for profit.

Glassblowing and Glass Production

Where can you learn a lot on glass blowing?

Venice, Italy is the world's leading centre for this art. Malta also has glass blowing.

Glassblowing and Glass Production

Why is viscosity important in glass blowing?

It is important because if the glass is kept at a little bit more than medium viscosity. It can be manipulable, thus blowing glass. U mad bro?

Glassblowing and Glass Production

Are there glass blowing schools or classes in southeastern United States?

Yes, we teach glassblowing via the flameworking method in the Southeastern United States. My name is Lance McRorie, and I was born and raised in the Southeast (Georgia), and I have dedicated my life to glassblowing. I operate FlameTree Glass School in a suburb of Atlanta, Georgia known as Historic Roswell, Georgia! Call us toll free at 1-888-FLAMETREE (352-6387) or visit us online at and simply click on workshops! GLASSBLOWING IS ALIVE AND WELL IN HISTORIC ROSWELL GEORGIA! We have the best teaching facility in the southeast for blowing glass via the flameworking method! We have glassblowing classes starting now! Classes on the FlameTree Glass schedule on goblet making as well. A good place to start is Glassblowing 1, and Glassblowing 2 at FlameTree Glass School! We have classes in all 4 areas of flameworking (glassblowing) curriculum; namely, 1) blowing, 2) sculpting, 3) encasement, and 4) murrine cane (mosaic canes in the venetian method/ Franchini Style Shaded Murrine).

Thanks, Lance McRorie / FlameTree Glass Founder

FlameTree Glass, Inc.

470 S. Atlanta St.

Roswell, Georgia

1-888-FLAMETREE (352-6387)

Glassblowing and Glass Production

What makes glass fragile?

Glass comes from sand. So it's probably its atomic structure.

Glassblowing and Glass Production

Can you make glass at home?

yes you can make glass in home but it will be very hard because although the materials are easy to obtain and cheap, you will need a VERY expensive kiln, personally, unless your very despirite, i wouldn't attept this because of the expense and because it is very dangerous


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