Introduction

Our objective is to use the art of glassblowing to produce small balls and bubbles. Once we mastered glassblowing, we attempted to add pigments to the molten glass. There are multiple ways of applying color to glass, but the process we chose was to roll the molten glass in powdered color/pigments. Glassblowing turned out to be much more challenging then we had planned. Learning this art's techniques took time and patience, although once we obtained the perfect bubble, we were very satisfied with the results.

Background

Although we have had no previous experience with glassblowing, Dale Chihuly’s work has inspired us to learn as a team. Chihuly developed a system using teams where he can produce large-scale contemporary sculpture from a formerly precious medium. He is best known for his multi-part blowing compositions, which we have attempted to emulate. Before Chihuly, the history of glassblowing developed as follows:

• 2500 BCE: Amulets and solid beads have been located. The earliest pieces of glass work on record in Syria
• 1500 BCE: Earliest vessels recorded in Mesopotamia and Egypt. Vessels were created by surrounding a core of dung and clay with hot glass.
• 50 BCE: The actual process of glassblowing was introduced to the Roman Empire and proved a more efficient technique than core-forming.
  
• 1200's CE: Venetian Glassmaker's Guild formed.
  
• 1291 CE: Venetian Glassmaker's Guild exiled to the island of Murano to eliminate a fear of fires in Venice and to control the development of the glass industry.  Here, glassmakers advanced production of rosary beads, glass mirrors and were able to create a clear glass called cristallo. With cristallo they were able to easily add color.
  
• 17th Century: L’Arte Vetraria was written and exposed the previously concealed secrets of glassblowing
• 1607: Jamestown settlers brought glassblowing to the Americas
• 1676: George Ravescroft developed a new technique where lead was used to create glass
  
• 1878: Artists such as Eugene Rouseau and Emile Galle exhibited glassworks as an art form rather than a domestic necessity at the Paris Exhibition.
  
• 1962: Harvey Littleton started the studio glass movement when he began experimenting with the art of blowing glass, by means of a small furnace to heat the glass. His movement inspired glassblowing artists worldwide.
• 1971: Dale Chihuly started the Pilchuck Glass School in Stanwood, Washington. This school is regarded as the center of the American Studio Glass movement.
  

Procedure

Materials:

-Glass Tubes
-Glass Rods
-Pre-Mix Torches
-Goggles – Didymium Lenses
-Carbide Knife
-Tweezers
-Graphite Paddles
-Beakers to store pigments and excess tubes and rods
-Pigments (Blue Cobalt, Smalte, Gamboge, Iron Oxide)

Before Handling Molten Glass:

We took a bottle of honey, as honey acts the same as soft glass, and rotated the honey on the end of a glass rod to practice the movement of soft glass. The object was to maintain a ball of honey at the base of the rod without the honey dripping or being pulled down by gravity.

Cutting the Glass Tubes:

To cut long pieces of glass tubes, we used the carbide knife to make one clear incision on the tube. Multiple incisions cause a fractured end which is dangerous and not good for the blower. After, cutting the glass we wet the incision with our fingertips and broke the tube away from us. To make sure that the cut was smooth, we quickly placed the rough end in a small flame to smooth the end surface without sealing it. Another technique we used was to put the center of a glass tube in the flame. As the flame begins to soften the glass, we twist and pull from the two ends to separate the pieces. This manner was more effective in blowing glass as it was an automatic sealant.

Lighting the Torch:

We used a helpful acronym to remember the correct process of lighting the torch. POOP stands for Propane, Oxygen, Oxygen, Propane. Thus, to turn on the flame we open the gas valve and then the oxygen tank. After this, we opened the small gas valve on the torch and used either a match or a striker to light the flame. After the flame has been lit, open the oxygen valve on the torch to create the desired level of heat. To extinguish the flame, remember the acronym and first close the oxygen valve on the torch followed by the gas valve on the torch. From here the flame will go out, but you must then turn off the oxygen flow from the oxygen tank and finally turn off the main gas valve.

Sealing the End of a Glass Tube:

If you chose to cut the glass, take the clean end of the your tube and place the tube into the flame. Allow the glass to slowly soften and it will naturally seal itself off.  Although, we never had this problem, it is possible to use tweezers to seal the end of your tube. To do this, use the tweezers to pull the soft glass into the center of the rod to avoid an awkward shape in the end of your tube.  As previously mentioned, it is also possible to simply allow the glass to seal itself off if you soften the middle of your tube and twist two pieces of the tube apart.

Blowing Glass:

Before jumping into blowing glass tubes, it is imperative to practice with solid glass rods. In the flame, glass rods develop a molten glass ball at the end. As previously practiced with honey, constantly rotate the soft glass to maintain a cylindrical shape. It is necessary to master the ability to handle the soft glass before attempting the actual process of glassblowing.

Now, with your glass tube form a molten ball at the end by slowly turning the tube in a circular motion under the hot flame. Once the glass is soft, like the texture of honey, put your mouth on the end of the tube and slowly, but firmly, begin to blow. Make sure to continue to rotate the tube to avoid dripping glass or disfiguration.

Begin at a moderate heat and adjust to higher or lower heat depending upon the size of your tube. A high-temperature flame tends to only soften the outside of the glass and neglects the interior. Also, at high temperatures, hot spots form which are softer and more malleable than the rest of your bubble. These spots tend to cause a hole in your bubble, also known as a “blow out.” Oppositely, a low-temperature flame will often not soften the glass enough to make it blow-friendly. When doing this make sure to evenly distribute the heat on the glass you are working with. Do not push the glass tube too far outside of the flame, as this will result in unevenness of heat.

Adding Pigment:

You can either produce your own pigments or buy already ground pigments. We chose to use pigments already made and ground for us. Before coloring a tube, pour some pigment to fill about ¼ of a beaker. Once your glass is molten, quickly remove your tube from the flame and place the tube into the beaker with your pigment. The pigment may flatten with the pressure and heat from the glass tube, but try your best to cover your molten glass with the pigment. If the glass hardens before you are satisfied with the amount of pigment, place your tube back into the flame to soften the glass and you can repeat the pigment application procedure.

Once your desired amount of pigment has been added, place your tube into the flame. Allow the glass to become soft and then follow the previous directions to blow the glass. You should see the color disperse throughout the glass as you blow. 

Producing a Multi-Blown Piece:

Your first step is to remove the blown ball from the long glass tube. To shorten the tube, use the above method of heating the center of the tube and twisting apart. Allow the tube to cool before touching otherwise you will burn yourself! Once cooled, think of a sculptural design that will be sturdy and aesthetically pleasing.

Now, take two of your pieces and fuse them together using the flame. In this step you will most likely have to use tongs if the pieces are too short and you feel uncomfortable with your hands close to flame. At this point it is up to you if you would like to continue adding glass to your piece. You may also chose allowing your piece to cool before adding another piece to your glass sculpture. Again, this is all a part of the creative process, make sure your piece looks appealing to you.

Observations and Data

Day 1: Thursday April 12, 2007

Today we started off placing honey on the glass rods so we got accustomed to the way hot glass feels.  We learned that in order to keep the honey on the rod and in a ball we needed to twist the glass rod to form the ball.  We also had to keep the rod pointed down so the honey rolled to the end of the rod.  We then learned how to operate the torch.  We learned gas, oxygen, gas, oxygen.  If you do oxygen before gas then a loud pop occurs and may frighten or startle the class.  Once we were used to the flame we place glass rods in the flame and turned the rod in the flame to produce a ball at the end of the rod.  The glass was much easier to work with than the honey.  I did learn to not touch the glass ball for a long time because after about 5 minutes I thought the ball was [not?] hot and it burned my finger. 

Day 2: Tuesday April 17, 2007

Today we made our first attempt at creating a ball on the end of a glass rod. We both had many failed and a few successful attempts.

• 1st attempt: EP made a ball with the glass and after the glass was extremely hot and it began to behave like the honey, she blew the end of the tube. Not much happenened but a small bubble did appear within the end of the glass ball.
• 2nd attempt: EM made a small ball at the end of the glass tube. She began to blow and apparently blew too hard. She blew a hole through the end of the hot, unstable glass. It is possible that the glass was too thin and small.
• 3rd attempt: EP reheated her first glass ball to see if something more would happen. The same phenomenon occured, the glass was too weak and she blew through the end.
• 4th attempt: EM closed the hole of the first glass ball to begin working again to blow the glass. She blew slow, quick breaths to see if blowing too hard was the cause of blowing through the glass. As she was blowing, she neglected to continuously rotate the glass and as such blew onto only one part of the bubble, again causing a "blow out."
• 5th attempt: We got a new glass tube to try again. We cut the tube into two pieces and EM began to create a ball. She created a larger and stronger ball than before, to hopefully allow blowing to occur without a blow out. She allowed her ball to cool while EP began to create a ball. The moment EM put her ball back to the flame it cracked from the temperature change.
• 6th attempt: EP created a larger and stronger ball and after EM's ball burst, she did not allow her ball to cool. She created a good bubble, but the flame was not hot enough so the bubble took a long time to make and was eventually blown through.
• 7th attempt: EM created a solid bubble with a good round bubble inside. After a long time of blowing some swelling occured and a slight bubble was created. Eventually, though, the bubble did burst.

Day 3: Wednesday April 18, 2007:

Today we decided to add color. We used blue cobalt pigment and smalte pigment.

• EM was finally able to create a solid bubble with the smallest size tube.
• When we added color it was difficult to get the pigment to catch on the glass – the glass also bends when put into the bowls of pigments.
• EP was able to create stable bubbles with the mid-size tubes.
• We began with the blue cobalt pigment but the granules were too thick and as such did not attach easily to the molten glass.
• We switched to a blue smalte pigment that was much finer. This pigment attached much more easily and thoroughly to the glass.
• Pigments caught into the glass if they were pigmented early as tiny balls and then blown – allowing the pigment to seep into the blown glass.
• At the end of the day, we had two small blue tubes and two mid-sized blue tubes.
• We initially thought that they pigments had caught into the glass well; however, it seemed after they cooled that the pigment had mostly solidified onto the surface of the glass.

Day 4: Thursday April 19, 2007:

Another student was also doing a glassblowing project, so we had to share lab resources. We worked out the schedule so that the other student could have the lab on Thursdays during class. During this time we researched more effective ways to blow glass. Time permitted us to work on the website as well. Today we completed the Introduction and part of the Background section of the website. We had some trouble saving our project and we ended up having to save the project to the desktop.

Day 5: Tuesday April 24, 2007:

Today we added yellow, gamboges pigment, and red, iron oxide pigment.

• EM began to heat a small tube and EP began to heat a mid-sized tube.
• When we added the gamboge pigment to both pieces, the pigment quickly burnt up and none of the pigment was caught onto the glass.
  • Apparently because the gamboge pigment is organic it cannot withstand such extreme heat and is then burnt.
• Instead of breaking the glass to get smaller pieces we melted the center, twisted from both ends, and pulled the pieces apart. This actually made the glass easier to blow because there was not so much material at the end to heat and blow.
• We switched to the red, iron oxide pigment since the gamboges burnt. The red was still slightly difficult to work with as it was thick and grainy like the blue cobalt pigment.
• We re-blew the blue cobalt pieces to see if color/pigments would stay in the pieces. They swelled slightly, but not much and the color remained in the pieces.
• We then cleaned the tubes to see if the pigment remained – and it did.
• Red pigment was taken by the glass, but it seemed charred by the flames and remained on the surface like the previous pieces.

Day 6: Wednesday April 25, 2007:

Today we created multi-blown sculptures with our previously blown pieces.

• To shorten the pieces and remove the bubbles we used the heating and twisting technique to separate the ball from the tube.
• When doing this we attempted to remove the bubble with as little tube left as possible. In order to do this our fingers were extremely close to the flame and in some cases we had to use tweezers to avoid burning.
• To adjoin pieces we took two shortened tubes at a time and put their ends in the flame to create a bond. We would let meld together by exerting force on either side and forming one uniform tube.
• Once a strong bond was created, we allowed the new piece to cool on the graphite paddle.
• Once the pieces were cooled we added additional pieces to our likeing.
• During this procedure we both burned our fingers. In EP's case she touched the bonded center of the tube while it was still hot. EM burned herself on a glass bead that was broken off during the heating process.
• One of the problems that we ran into during this process, was that often bonds were not strong enough and they broke. We were forced to continue to reheat many of our pieces. Unfortunately, the stronger the bond meant the longer the time in the flame and, thus, the shorter the tube.

Day 7: Thursday April 26, 2007:

Today we photographed all of our finished pieces and continued to work on the website.

• We were very satisfied with our final projects as we were taking pictures of them. Unfortunately, a few pieces broke while we were moving them - the bonds were simply too weak to withstand much movement.
• We were able to repair each of the damaged pieces by putting them back into the flame. The other glassblowing student was very nice in allowing us to use the glassblowing bench to repair our pieces even though it was not our assigned day.
• We had extra class time, so we continued to work on our website.
• We were able to retrieve our previous work with help from a computer assistant.
• We finished the background and procedure sections.
• To do this we looked through our notes, used information from the book and internet sites.

	Three part "Clear" Piece
	Three part "Sitting Blue" Piece
	Four part "Sitting Clear" Piece
	Multi-Part "Blue Flower" Piece
	Three part sitting "Light Blue" Piece

Conclusions

Our hope for a perfectly shaped glass bubble was not realized. Most of our larger bubbles burst, so we were forced to create only smaller bubbles and work with them to avoid blow outs. We learned during this project that you must maintain a controlled flame. Too hot of a flame softened the glass too quickly and it was impossible to work with. Oppositely, too cool of a flame would not heat the glass quickly enough and would not permit sizable blowing.

To add the pigments we did what we were told. We added pigments to small glass bubbles and blew them to allow the pigment to disperse throughout the glass. Unfortunately, the pigments usually just solidified onto the surface and after time would chip away. Depending on the heat of the flame and the molten glass, the pigment would either immediately burn or begin to disperse into the glass and later burn, while in the flame.

We were able to create multi-blown pieces influenced by Dale Chihuly. Many of the pieces show examples of blow outs and burned pigments. However, we were still able to use these pieces to create contemporary glass sculptures. Initially we believed that the pieces would be sturdy and that the bonds were strong enough to hold multiple pieces together; unfortunately often pieces would break at the focus and end up resulting in a disconnection.

Links

http://www.chihuly.com/

[In August 2007, this link does not seem to work] http://www.glassblowing.com/hotglass/history.php

http://en.wikipedia.org/wiki/Glassblowing

http://www.sewanee.edu/Chem/Chem&Art/

Other References

Dunham, Bandhu Scott. Contemporary Lampworking: a practical guide to shaping glass in the flame. Salusa Glassworks: Prescott, AZ. 1997.

Acknowledgements

Dr. J. L. Bordley, professor of chemistry, University of the South

Dale Chihuly, multi-blown piece glass sculptor