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Old 01-13-2004, 03:50 PM
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Richard Huntrods Richard Huntrods is offline
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Location: Vancouver Island
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I think I may have an answer to my own question. I cooked the spruce pine batch for 12 hours at 2250 last night (not including 5 hours to get the temperature at 2250 throughout the pot).

At noon today the glass was relatively clear on top (no significant bubbles), so II gathered a sample. It was full of bubbles (as expected), but they were uniformly distributed throughout the sample, and all were "pinhead" sized.

So - I started the squeeze. (it will be at 1920F).

Looks like this process worked almost perfectly!

The 40lb crucible took almost a full bag of Spruce Pine batch (50lbs), but since it's about 20% water, this is right. I could have put it all in the crucible - but then I'd have been scooping glass out last night. As it is, I had about 1/4 of a large peanut butter container left over. Next time I think I'll reserve a whole peanut butter container aside to prevent the expansion from getting near the lip.

One other thing abou SP batch - I added batch at room temp (-2 C or 28F) to the crucible which was at 2150F. There was an initial "foosh" as the batch hit the crucible (or melted glass), but no popping or any other unpleasant side effects. A VERY NICE batch to work with!

Now - tomorrow night - the big test. The first official "blow down" of the Tin Shack Studios!

I took some pictures of the first two gathers (at 2250, before the squeeze) to show how it looked. Again, on my web site.

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