Thursday, January 15, 2009

The Sad Saga of the Bronze Clay Bell



A few weeks ago I posted about my bronze bell attempt. After the holidays it took some time for me to get around to working on the clapper for the bell, but it finally got done last weekend. On Monday afternoon, I carefully loaded the bell into the stainless steel container of activated carbon, along with its clapper and a few odd pieces. I decided to follow the modified firing schedule supplied in Hadar Jacobson's new book, because it was substantially faster.

On Tuesday morning, the moment of revelation came. Alas, the kiln goddess did not smile upon this firing. The bronze bell was constructed with two different size lentil halves stacked one upon the other. I did worry about trapped air, so I drilled a vent hole on the inside to let air escape. Unfortunately, it appears that did not work successfully. There is an opening in the bell around the join on one side, with corresponding blackening of the bronze where the air oxidized the metal. In fact there are a couple of small holes through one side of the bell.

The bell does ring prettily, better when tapped on the less oxidized side.

Time for a repeat construction. I guess it will be a good experiment to see how fast I can do a known operation. Modifications are coming I think though to prevent the air trapping. I will return to the slower ramp speed, since I can't help but wonder if the fast fire contributed to the pop.

2 comments:

  1. I think this is fantastic! It's still a work in progress. Fill the cracks with enamel or resin. use a scratch brush to remove the oxidation and re color with LOS or the flame of a torch. Theres still so much you can do with this piece. You're just not finished looking at it.

    By the way, I've used the new fast ramp successfully. Were the cracks there in the dry clay? Did you carefully knead the fresh lump to incorporate all the moisture that seems to migrate to the skin of a new lump? I like putting a drop or two of a glycerin/water solution in fresh clay and refreshing it periodically with lavender water. Try the new schedule again before you go back to the 9 hour one.

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  2. I'm not giving up yet! This kind of failure just brings out my stubborn streak. ;-) It's the experimental scientist in me! Gotta figure it out.

    No, the cracks were not there before. Yes, I'm a kneading fiend. I'm sure the fast ramp is excellent for many things, just not something that might have air needing to escape through a limited opening. Lesson learned.

    I have another ready to fire, plus many extra parts where I've learned other lessons. But, hey, I'm getting faster and cleaner at making the bells!

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