Here a some pictures of my experiment.

I made some bricks using clay and charcoal, and experimented with different ratios of clay and coals.

I have decided that it works best if you have a really wet slip, as it mixes in with the coals much better. Too thick and the clay tends to get stuck to a small clump of coals and won't mix in very easily. Too thin, however, and it will be too weak.

You can see in my picture of the formed up bricks where I changed the mixture a few times. It is better to have a little too much clay than not quite enough of clay, because if you do not have enough it is far too difficult to get the bricks out of the form without them crumbling.

Sloppy slip

real wood charcoal, made in my own kiln[

Smaller pieces work best, which is good because they aren't useful for other the things that I use my charcoal for!

The mix

the form, a little oil on the sides helps the bricks to come out easier

lets make some bricks! A small batch of 25 bricks made for test purposes.