Mark C.

Hey Mark,

I am an American Potter working and Living in Windhoek Namibia. Been a potter since 1968.  My mom is from Scotia, CA. Redwoods.

Just read your post about steel bracing a kiln.

I am building a cross draft wood fired kiln out of bricks made of Magnesia. 8x8x 3" tapered. Makes a 3M circle. Donated from a Cement factory. Not ideal but they fire to 1700c. Can't get wet though. Causes them to fail. Weird. 

Anyway,  the design id from Olsens Kiln book. Page 126-8. Also from a Dec 1977 Ceramics Monthly Mag.

Aparently the bracing wasn't secure enough. Maybe the valve lifte® springs that gave way but when we removed the arch form support the wall opisite the chimney spread open about 1/2 inch. The arch is made up of 7 cources of 29 bricks = 232.5 bricks that weigh 9 k each = 2092.5 Kilos = 4603.5 lbs!

So we are placing buttresses on the wall/ We took off the arch and will repair any spreading. I will double the existing thickness of the wall with red brick and cement and add steel or cement buttresses. And better bracing at the middle and bottom of the kiln. Oh yeah and get rid of the springs!

Any thoughts?

John Hunter