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Glassblowing and Glassworking with ColorAmanda Sicat Roush |
I decided to try something with glass blowing for my final project, when I saw the suggestion in the back of our lab manual, because we had not worked with it before, and I was curious. After meeting with Dr. Bordley and looking at previous student projects with glass blowing, I decided to experiment with glass blowing and compounds to create color in the glass. I wanted to see what colors would form when I added or attached compounds to the glass. I got the idea of adding compounds to glass by doing research online about glass blowing and color.
A very brief history of Glassblowing
5000 BC – (Around 5000 BC) Phoenician merchants accidentally became aware of glass in Syria.
50 BC – (Around 50 BC) Somewhere in the Roman Empire, the technique of glassblowing was discovered.
1962 – Chemist Dominick Labino and ceramics professor Harvey Littleton begin the “Studio Glass Movement” when they hold two workshops, experimenting with glass blowing, at the Toledo Museum of Art.
The purpose of this experiment is to experiment with glass blowing techniques and coloring methods. I would like to see what factors and variables affect the product of the glass and how it takes the color.
I think the longer the glass is heated, the worse the results will be because, if glass is overheated too much it could become too soft to manipulate without breaking or collapsing. I think overheated glass would be too fragile for blowing.
I think the fusing method may work best with coloring glass because it seems to work slowly with getting the color in and uses two rods; so it is somewhat easier to manipulate. I also think there may be complications with coloring the glass bubbles because, from what I have seen, color is usually added after the bubble is formed, and I would like to try to add the color before blowing the bubble.
Note: Be sure to wear eye protection. Depending on the type of glass work, special glasses are available. If using "didymium" glasses, used when working with borosilicate or soft glass, the yellow glare from glass is filtered out. It's an amazing difference to look at what is happening to the glass in the flame when looking at it without glasses compared to with the glasses.
Materials used:
-small burner (for torch purposes)
-glass rods and tubes (for softening and blowing)
-glass bench
-eye protection (see previous photo)
-metal slab to allow glass to cool
-metal file (for cutting glass)
-striker and/or matches to light flame
-mortar and pestle (to crush compounds)
-scoopula (to transfer compounds)
-watch glasses (for crushed compounds and compound application)
-burn cream (for first-time glass blowers)
-compounds: Cobalt Chloride, Cupric Sulfate, Lanthanum Oxide, and Uranyl Nitrate
Lighting the torch:
Preparing a rod or tube
If working with a rod:
If working with a tube:
Preparing the compound:
1. Place the end of tube or rod into the flame and constantly keep rotating the rod until a ball of glass forms. For blowing, quickly remove from flame (after ball has formed) and blow into the tube to create a bubble. Results will vary.
2. When glass is heated, apply to compound by pressing or rolling and place back into the flame. Repeat as desired.
3. After compound is applied and glass placed back in the flame, remove and blow the open end of tube. Repeat as desired.
4. Finally place glass on metal slab and allow to cool.
April 16-17 and 19
First, I practiced rotating rods by using an exercise suggested in Contemporary Lamp working where I practiced rotating honey on a rod. I dipped the end of a rod into honey and collected it. Next, I rotated the rod and practiced until I managed to maintain a ball of honey without it dripping. Honey is great to practice with because glass is similar to the consistency of honey when it is ready for blowing. I practiced rotating the rod until I felt comfortable.
Professor Bordley showed me how to work with the torch and glass bench. He showed me how to use light the torch.
I tried to get familiar with the glass by playing with or testing it with the torch. I practiced "cutting" glass with a flame by rotating a rod, holding each end of the rod, with the center of the rod in the flame. I rotated the rod and waited until the glass was soft enough, then I twisted and pulled the rod apart. This is ideal for glass blowing with tubes, as this method leaves an end of the tube already sealed.
I tested to see if the glass was softened by rotating the end of the rod in a flame, and then stamping the end of the rod into a round mold to see if the glass would take any shape, indicating whether it was melted or not.
After feeling somewhat comfortable with the rod, I went on to try glass blowing. I took a glass tube, that I had separated earlier with a flame, and placed the sealed end in the flame while constantly rotating the rod. I kept rotating the rod until a ball of molten glass formed. Then, I quickly removed the tube from the flame and blew into it. My first attempt had no success at all. The other end of the tube had not changed at all. I tried again, this time keeping the tube in the flame longer, and still had the same results. I adjusted the torch by adding more oxygen to the flame. I then heated the tube even longer than before and experienced a small victory - the ball of glass on the end of the rod slightly expanded. Later, I tried glass blowing with a smaller, thinner glass rod. When I went to blow, I made a bubble but it quickly popped. I think it popped because I blew too hard. So the amount of strength you use to blow and the size of the rod affect the success of bubble creation.
I decided to test to see how I could attach the compound to the glass. I first tested using rods. I would rotate the end of a rod into a flame, and when I felt it was ready, I stamped the melted end into the CoCl2 compound , and quickly put the rod back into the flame for a bit. Afterwards, I allowed the rod to cool on a slab. I did not get the kind of color result I wanted.
Monday, April 23
| Compound |
Oxygen versus Gas |
Observations/Results |
| Cobalt Chloride | Oxygen > Gas | -compound is a magenta color -able to make a nice small bubble -was only able to attach a small amount of compound to the glass - color looks like a dark blue leaning towards black -when I applied the glass to the compound, it burned a rich navy blue, then almost immediately turned into a dark purple color. *pictures below -after compound was attached to the glass, and the tube was place back into the flame, the compound burned a light blue color and then darkened |
| Cobalt Chloride | Oxygen < Gas | -I first made a sphere with the glass, then heated it in the flame. -After forming a sphere, I rolled the tube into the compound twice and reintroduced it to the flame. -Results were similar to the first try, but the compound attached thicker, perhaps because I rolled the tube into the compound twice rather than just once. -The glass seemed to take longer to melt in this flame than in the one with more oxygen. |
| Cobalt Chloride | Oxygen > Gas | -melted a small ball on the end of the tube, then rolled in compound, and put back into the flame. Afterwards, I removed the tube from the flame and blew a very small bubble. -results were much more pleasing for me. A blue-gray color appeared where the compound had attached to the glass. -color is easier to see with a magnifier.
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| Cupric Sulfate | Oxygen > Gas | -Before crushing, Cupric Sulfate is a bright blue solid. Afterwards, it is a lighter blue powder.
-only applied compound once -At first, compound on rod appeared a red color, then quickly turned into a silver-gray color -when viewed with filtered glasses, the compound burns green in the flame
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| Cupric Sulfate | Oxygen > Gas | -attached and rolled glass into compound twice and blowed after compound application -a subtle, light ruddy color appears in the glass this time -I later rolled the rod into the compound more and blowed, and the color was more visible |
| Cupric Sulfate | Oxygen > Gas | -softened the glass longer -rolled the glass in the compound and applied the tube to the flame and then blew into the tube three times -a better bubble formed and the color results were better -color is a dark ruddy color with dark edges
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| Lanthanum Oxide | Oxygen > Gas | -oxide is a very fine white powder and did not need to be crushed -glass was a pearly white color -part of where the compound was attached, burned a dark dull color |
| Lanthanum Oxide | Oxygen < Gas | -glass took longer to soften -color is the same result as before -compound burned a bit more than first try |
| Uranyl Nitrate | Oxygen > Gas | -used a rod instead of a tube, as advised by Dr. Bordley, considering that Uranium is radioactive... -when crushed, compound looked like a bright yellow powder -when hot glass rod was stamped into compound, the compound quickly melted into a liquid
-attached compound twice and resulting color was an olive green color and a darker green where the glass had been more exposed to the flame -was hoping that Uranyl Nitrate would cause the glass to glow in the dark, but it failed |
Cobalt Chloride before any heated glass is applied. |
Cobalt Chloride, right after heated glass is applied, affected area is a royal blue color. |
Cobalt Chloride, soon after heated glass has been applied, quickly goes from the royal blue color to a darker purple color. |
Tuesday, April 24
I did research and worked on my web page in the library.
Thursday, April 26
Compound |
Oxygen versus Gas |
Observations/Results |
| Cupric Sulfate | Oxygen > Gas | -had trouble blowing a bubble -only applied compound to glass once -color was a dull dark blue/black |
| Cupric Sulfate | Oxygen > Gas | -still trouble with blowing a bubble, must not be waiting long enough for glass to melt -applied compound twice and rolled rather than just sticking -similar results to first test, but blue is a bit more visible and some dark gray on areas that were exposed longer to flame |
| Cupric Sulfate | Oxygen > Gas | -waited longer for glass to melt, was able to create a small sphere (finally!) -rolled glass in compound and then placed back into the flame three times - same dark blue colors appears as did in previous attempts and a silver where the glass has been exposed longer to the flame |
| Cobalt Chloride | Oxygen > Gas | -had trouble forming a bubble -applied heated tube to compound only once -produced a nice ruddy color with some dark silvery bits |
| Cobalt Chloride | Oxygen > Gas | -heated tube a bit longer -attached compound twice -small bubble formed -richer ruddy color with dark edges |
| Cobalt Chloride | Oxygen > Gas | -heated a bit longer than previous attempt -attached and rolled compound thrice -color came out smooth and ruddy similar to that in the previous attempt |
After actually working with glass blowing, I realized that my original project plan would not be possible as glass blowing is difficult to work with. There was no way for me to measure the amount of gas and oxygen used other than to know which knob was turned more. Also, I discovered so many different factors and variables affecting the ending results of glass blowing. Also, my lack of glass blowing experience and skill hindered my experiment. I finally decided to test and compare the outcomes by varying the amount of oxygen and gas in the flame and the amount of times the glass was applied to the compounds. I also experimented with different tube sizes.
In the end, in my opinion and considering the results, the thinner the tube,the more oxygen than gas in a flame,the more compound applied to glass, and blowing after heating glass with compound on it produced better outcomes for me. I think the thinner tubes worked well because they were faster and easier to heat. I think the oxygen not only helped the glass heat faster but helped the color appear better. I think blowing the tubes also helped the compounds produce color in the glass too.
http://www.arthistoryguide.com/Glass_Blowing.aspx
http://www.blm.gov/historic_bottles/glassmaking.htm#Free-blown%20Bottles
http://chemistry.about.com/cs/inorganic/a/aa032503a.htm
http://en.wikipedia.org/wiki/Glassblowing
[August 2007. This link does not work.] http://www.glassblowing.com/hotglass/history.php
http://www.glassonline.com/infoserv/history.html
http://www.wikihow.com/Blow-Glass
Dunham, Bandhu Scott. Contemporary Lampworking: A Practical Guide to
Shaping Glass in the Flame.
Arizona: Salusa Glassworks, 1997.
Dr. Bordley for supplying necessary materials, suggestions, and encouraging/trying to teach me how to use a striker.
Professor Fitz for advice on the first day I was experimenting.
Dunham's book (cited above) for main ideas on blowing glass and adding color to glass.
