Homemade Cinder Block Kiln

Here are some pictures of my first kiln. I built it from cinder blocks, stepping stones, and dirt. This kiln really worked. I don't know how hot the kiln got. I didn't use witness cones, I forgot to put them in. However, it did melt a cone 06 commercial glaze, and I was thrilled! It was so small only a few pieces could be fired at a time. I built the kiln over an existing trench just as an experiment, with cinder blocks that I had on hand.

 

 

 

 

To view some of the pots that were fired in this kiln go to the Earlier Work Gallery.

The chimney (not shown) was simply stacked cinder blocks. Left side of the top picture. The flues were the openings in the blocks. Stepping stones were put over the top as a damper. Several pinch pots and hand built earthenware pieces were fired green (not bisqued). I was so excited that I forgot to take pictures before I unloaded the kiln. I did take a few the next day, and if I can find them I will get them posted on my gallery pages.

The fire was stoked from this end. A mixture of seasoned pine and hardwood was used as fuel. At one time during the firing, the firebox was so hot, the kiln sounded like a rocket, and flames were shooting out of the chimney, but were not visible at the flue exit. Only about a foot higher were the flames visible. At the end of the ten hour firing, the opening was sealed up with blocks and dirt, and left to cool. Cool down took over a day, about 36 hours before the pottery was cool enough to hold.

These pictures show the inside of the kiln after the firing. I was supprised to find the ceiling (bottom pic) so "clean". I expected to see soot everywhere. The pots were placed on the ground at the far end of the kiln. (chimney end) The chimney didn't survive the firing. The blocks developed cracks during the firing, and completely fell apart when I was taking it down to unload the fired pieces.