| Effective teaching requires clear communication and the
creation of a comfortable, friendly environment or atmosphere in which
to learn. Demonstrations that allow audience participation tend to be the
most successful and the educational content can be specifically tailored
to your audiences' age and capabilities. Note the content of these demonstrations
is scientific in nature. The intent is to promote the sciences in general
and scientific glassblowing in particular. When possible try to coordinate
the glassblowing with a project the students may be involved with. An experiment
in the chemistry lab may mean more to a student if he/she uses a test tube
that he/she has made.
Please
note - Safety is always a concern when working with glass, flames, and
compressed gases. Set up your demonstration area in a manner to protect
people and property. Use appropriate protective clothing and safety glasses,
comply with all safety and fire regulations and guidelines and work with
an assistant.
Good
demonstrations involve participation:
1. Tell your students what they will be doing
2. Show your students what they will be doing.
3. Instructor/student interaction over what they have just seen.
Encourage questions, observations and interaction. Have
students answer some of the questions from their classmates.
Note: In an attempt to add to the educational process and student participation,
I have recently modified the format of the glassblowing demonstrations.
Selected students will spend a 1/2 day at ECU's Glassblowing facility
learning some basic glassblowing skills and viewing first hand a working
glassblowing shop. These students will in effect become the "instructors"
to their classmates when we do the demonstration a day or so later. The
student instructors do an admirable job of sharing information with the
class, answering questions and encouraging participation.
| Blowing
Glass Bubbles - This demonstration allows
students of all ages to actually experience glassblowing . The participants
do not handle the hot glass or the torch, and do not come close to the
flame. The key is to have a rather long blowhose
(with individual throw-away mouthpieces), keeping your students away from
the hot glass and flame, but still close enough to observe the glass reacting
to the "blowing" into the blowhose.
Suggestions:
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| Cutting Glass - Demonstration
showing various methods of "breaking" glass.
Suggestions:
-
"Accidentally" drop a beaker or flask
on the floor - a great way to get the attention of your class. If it breaks
- a good example of an "uncontrolled " break (but not very useful to the
glassblower).
-
If it does not break - demonstrate
the many characteristics of glass and the roll glass design (bellows and
coils) has in glass apparatus. Discuss the difference in tempered, annealed
and stressed glass.
-
Show controlled
breaks - Scratch and snap; hot rod with scratch. If in your shop -
the cut-off saw, etc. Explain applications.
Show controlled breaks (flame assisted)
- Flame cuts, scissors cut. The scissors cut can be performed by the student.
Simply heat a length of tubing as if you were to pull a point. While still
red hot have the student quickly cut the tube in half !
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| Silvering - this demonstration
requires more preparation than most, but is a good way to incorporate a
little "chemistry" into the lesson plan. This demonstration has been successfully
given to students in the 6-8 year old bracket, but may be better suited
for those a little older. The amount of technical information given may
vary quite a bit depending on the age group.
Suggestions:
Glass preparation:
-
Have students blow bulbs. Use same
basic instruction as in Blowing Bubbles.
-
Use 19 mm medium wall tubing - try
to "target" a bulb about 25-30mm as your objective. Do not blow thin bulbs
for this demonstration!
Silvering:
-
Prepare silvering solution mixtures
before-hand (Brashear process).
-
Protective clothing a must. Eye ware,
lab coat, and latex gloves! Why?
-
Have students add proper pre-mixed
solution mix to bulb. Use recommended Brashear process steps. What chemicals
are being used?
-
Complete silvering process by placing
and shaking bulb submerged in a warm water bath. What type of chemical
reaction takes place? Variables?
This demonstration requires assistance
- and works well in breaking up the class into two groups, maintaining
interest levels over an extended period of time. |
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