Pressing firebricks

Ive been working on a home addition at my house for over a year now. I dug out along the foundation to lay drainage pipe and heating tubes from the wood furnace. The soil is a very sticky clay here. Perfect for the firebricks we have been making for the lining of the furnace.

After sitting in the sun for several days with no rain, the clay hardens into stiff clumps that need broken down for mixing with sand.

50% clay, 40% sand, and 10% portland cement.

Here is a pile of free creek sand taken from my property.

The mix is damp but not soggy. It will clump in your fist.

And here is the result from the press!