Stacked Bowls

The bowls I have attempted seemed to have created almost as much drama as my bibles.  In fact, as I sit here writing these notes, I have no idea if any of my bowls will survive the current firing–either in float glass or soft!

We have only about 1 month before Christmas break and so many assignments to complete.  Some of what I have worked on this term, may have to merely be carried over to the winter term.  And I guess that I can live with that!

Three separate waxed forms that I made into 1 single vase.

Bottoms were cut out to allow for formation into 1 complete piece forming a vase.

Here are my wax forms.  I had 3 bowls that left me wanting some excitement.  I began stacking the bowls and made them into a vase (which I liked alot).  However, as you can see from the finished  float or plate glass piece here, my glass did not fully melt to satisfy allowing the glass to flow all the way to the bottom of the plaster.


I need to mention here that before anything got done, I had some major setbacks in accomplishing these bowls.

One of the molds leaked into the kiln and as a result, the element broke and the kiln is out of action.

The cracked flower pot from the glazing present when I bought the pot reacted with the glass I melted. Note that because float glass takes more to completely melt, it didn't leak and cause the damage that might have taken place with a similar mold containing soft glass

What also shows from the picture of the flower pot is that the glazing on the pot does not work well as a reservoir for glass.  It was therefore a poor choice of glass reservoir on my part.

The resulting piece you see here came out of the mess shown above.

Still, you can tell by the colour that this plaster mold contained float glass.

The green of float glass is much stronger and more translucent than that of the slight green (but more transparent) cast noticed on the bowls of soft glass

In the program I used with the float glass, what can be belatedly noted was that the melting temperature for float glass needs to be set somewhat higher than 850 degrees Celsius (perhaps 900 or 950 is more realistic for this much glass).

Also what we are beginning to figure out is that the reason for my cracked molds seems to stem from my inadequate allowances for drying out — while the firing is gaining heat.

My molds are quite often (but not always) done while the mold still has a great deal of moisture.  The period calculated for drying is supposed to happen long before I reach 600 degrees Celsius.  I had misunderstood and was working to have the moisture vented out of the kiln by the time it reached 600 degrees.  What I now realize is that by the time it passes from 120 degrees, there should be only the slightest bit of moisture (known as chemical moisture) showing on a clean piece of glass where the kiln is slightly opened.  Chemical moisture does not typically dissipate from a piece until it reaches the 600 degree mark.

The steps to this input were actually included as of November 27.  The firings took place as far back as October 31.   I was using kiln #2 and set the firing to begin as of 2 pm.

I have learned so much from the time I initially began to write and submit these pages until now!


  1. 4: hrs                             ^   90 degrees
  2. 14: hrs                           ^  110 degrees
  3. 26: hrs                           ^   120 degrees
  4. 34:  hrs                           ^   600    “
  5. 38: hrs                         @  600      “
  6. 38:01                             ^  850       “
  7. 52:  hrs                           @ 850       “
  8. 52:01  hrs                            540       “
  9. 68:  hrs                             @ 540      “
  10. 90:  hrs                                  400     “
  11. 110: hrs                                     50     “

Let’s move on for the next couple of days….

You can see here the wax forms of 3 bowls.  What you can’t see (because I forgot to take the picture) was a small urn attached to the top inside the plaster mold.

For our next more current effort, we put lots of blocks in to prevent the form from breaking and leaking if any cracks develop.

My pics aren’t showing that when I set up the kiln #4 for firing on November 2, I got shut down by my program head just prior to reaching 600 degrees.

The mold had not sufficiently dried out to satisfy his piece of mind.  So Koen had me shut down my program because he could see cracks beginning to appear in my mold and did not want a repeat performance of me downing another kiln from leaking glass.  That was a fortuitous moment!

I have adopted an attitude that whenever one of my instructors gives me a direction order, I follow it–no matter how stressful it may appear to achieving my goals (in that specific moment).  I am so glad that I follow that mindset every time.


  1. 3:  hrs                              ^ 90 degrees
  2. 12:  hrs                            ^ 110   “
  3. 29:   hrs                          ^  120   “
  4. 35:   hrs                            ^600   ”              ** **This was just about to happen when
  5. 37:  hrs                            @ 600  ”              Koen had me stop the program and so
  6. 37:01  hrs                         ^ 850     ”            this part never actually ran as you see it
  7. 50:  hrs                             @  850   ”            here.
  8. 50:01  hrs                                516   “
  9. 80: hrs                                 516   “
  10. 105:  hrs                            @ 390  ”

    Can you see how we blocked all around the form to prevent the plaster mold moving anywhere?

  11. 125:   hrs                                   50   “

Some days later–November 7, Orion & I packed a different kiln #2 for firing at about 3:pm using soft glass.

Same mold but now the things is totally dried out so drying is not the issue here…


  1. 2:  hrs                       ^ 100  degrees
  2. 7:  hrs                        ^ 120     “
  3. 12: hrs                        ^ 600                                *** Again we were foiled at this point
  4. 15:  hrs                        @ 600    ”                   of temp.  in a different kiln
  5. 15:01   hrs                   ^  850     ”                    Before resuming, the temp actually fell
  6. 28:  hrs                        @  850    ”                 back to about 400 degrees Celsius
  7. 28:01  hrs                         516    “
  8. 58:  hrs                          @  516     “
  9. 103:  hrs                             390    “
  10. 148:   hrs                               50    “

However….  there was an issue.  I happened to notice that the kiln stayed at just under 600 degrees Celsius for longer than the allocated time of 11 + hrs.  It took me about 2 days to realize that it had stopped heating and was waiting for me to realize some other problem had developed.

Again Koen told me to crash the program while waiting for an answer.  Jason was not yet arrived for the day and without my kiln casting instructor to consult, Koen’s first line of defense is “shut it down” and wait for Jason to fix it.

Can you see how we blocked all around the form to prevent the plaster mold moving anywhere?

Luckily, Jason arrived within the 1/2 hr and figured out that one of the elements had failed and was preventing the kiln from reaching maximum heat.  He was able to fix the problem and set my kiln to holding while I re-input  a modified program.

Final programmed steps:

  1. 0.01 hrs                 from 400 – 600 degrees
  2. 3:  hrs                          @  600  degrees
  3.  3:01 hrs                          ^   850   “
  4. 18:  hrs                             @  850   “
  5. 18:01    hrs                            516    “
  6. 48:   hrs                              @  516  “
  7. 90:   hrs                                    390  “
  8. 138:   hrs                                     50   ”

    Three stacked bowls & an urn that is intended to pour water than leaks from bowl to bowl (as soon as I can assemble the pieces to form the base with the pump)

Those flower pots shown at the top of the plaster were to hold (hopefully) enough of the clear soft glass (note the lack of green tinge) to fill the form.  As of the final writing (November 27), the flower pots had completely emptied without mishap (no glazing so no cracking from incompatibility problems).

Rough edges are partly from the interference of clay and plaster getting stuck in the glass as it moved to fill the form.completely emptied and appeared to be almost exactly the right amount.

However, then one of the elements failed while the kiln was firing to melting point and so we were lucky enough to have a technical assistant who could work his magic–even while the kiln was loaded and hot.

When I last looked inside the kiln, those pots were empty of glass but they were glowing red–just prior to the temperature falling back to cool.

In the final analysis, I have decided to make a small fountain out of my piece to offset some of the things that took place within the piece itself.  Plaster got trapped inside some of the glass while things moved that weren’t intended to move.

Look closely and the clay between the bowls is still visible (even if the small urn at the top of the bowls is missing)..

I had used wax to form my bowls; but clay to form the platforms holding the bowls together.  That is an issue of developing skills to work with wax.  As of this writing, I have begun to make more bowls that have no clay as part of the form so that when I melt the wax from the plaster mold, it will be just wax I am trying to remove.  Some of my clay got stuck and never did make it out of the form.

In closing off at this point, I should also mention that Jason has since found time in his very very busy schedule to replace the broken element of my previous glass mishap.  We are no longer down by 1 kiln.



About whendidwestart

I am what I consider to be starting my life over. I have been studying art for 2 years and have begun 3 years of glass Crafts & Design in Sheridan College. I am also discovering how much I like to write online--a good thing because applying for scholarships will have one writing a lot of essays. My summer 2010 was about finding the funding to cover my expenses. Whatever I thought my life would be about this past year of school, I never expected to be trying to help 2 daughters in 1st year college when their funding fell short. My summer 2011 became about sitting still long enough to consider the impact of my goals. I look for $$ for supplies and I look for $$ for equipment for when I complete my program. I have a commercial size compressor for running a sandblaster; but no sandblaster. I have a Skutt kiln; but cannot afford the hydro required to fire it up. I have some stained glass and supplies; my program has just had stained glass artist Joseph Cavalieri from New York to input ideas on how we could incorporate what he does to what we do. When I finish here at Sheridan, I expect that I will do mostly cold glass work--stained glass and sandblasting..... Perhaps some work with stone because many of the properties of stone are similar to working with glass! I am also about sharing information with others who want to break from traditional thinking about a lot of things. For example, I have been a Bell Canada since I left home at 15. My Mom used to be a Bell Telephone operator when Bell was the only game in town. My Stepmother and her sister and my sister all worked for MaBell. I once worked for Bell Northern Research and until recently, I thought I would be a Bell customer for life. I am not so certain of that any more. I want to know more about economical phone plans (land & mobile). Are there any out there? I have recently begun to realize that to stay ahead of the game, one would almost have had to study law to understand the significance of a phone plan--no matter what the ads say!
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