One of the things I love about ceramics is that you can never stop learning. You could dedicate your life to the process and you will never master it all. This can also be frustrating at times. For the most part the ceramic community is loaded with people who are willing to share their knowledge, time, experience, triumphs and even failures. I guess I have a failure to share with you today, but I'm passing this information on so you don't make the same mistake.
REFRACTORY BRICK...it's not created equal. I purchased 600 hard brick on craigslist.com a few years ago. Good brick, but not for my application. It's brick for a glass kiln, which I didn't have a clue, nor did any of my friends, that it's made for very high temperatures, but not the changes in temps we potters put it through. We made my grate, posts and a couple walls out of this brick and during the first firing the grate started to break up. Of course I was as stressed as could be because the posts were cut from this brick that was falling apart. We thought maybe we didn't leave enough slop between bricks and the expansion destroyed them so we made the grate the same for the second firing, except we left lots of slop for the bricks to expand and move. Well, they fell apart again. The back wall of the fire box has a few cracks, but we think because they are under compression they are holding up. The posts didn't crack either, thankfully.
Since this second grate fell apart so bad I felt I needed to start asking around and see if anyone had some answers. Stephen Mickey didn't know, but suggested I try Jack Troy. Jack is brilliant and answered my call for help with a wonderful explanation. As I said earlier glass kilns are brought up VERY slow and held at a constant temp and their brick has a lot of silica. So now I have new garden brick. Of course I won't be using the posts we cut anymore and we'll have to figure out some sort of covering to protect the one wall that gets heat. Lesson learned.
Pictured are some of the wonderful results from firing #2. Bowls with wonderful shino glazes and soap dishes.
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