Making some clay

Stared working on the panels for the forge. Started by getting the proportions right. After half an hour resurecting some algebra skills I came up this this:

EP Kaolin - 31.75 lbs
Aluminum Oxide - 13.25 lbs
Zirconium Silitcate - 5 lbs

I used the bathroom scale for the EPK. I then used a lab scale I have for the smaller weights. The 31.75 lbs of Kaolin filled almost an entire five gallon bucket. The bucket was then split into two buckets by sight. As the Aluminum Oxide & Zirconium Silicate were weighed out they were added to each bucket. Finally the millet and a little sawdust was added. I decided to add the sawdust to give it some strength while it's drying. Hopefully that will help prevent cracking to some extend. In all about 15 lbs of millet and about a pound of sawdust was added.

Adding the millet

Dry clay ingredients before mixing

Adding the sawdust

Drill with mixer

Clay after mixing with drill

Once the dry ingredients were divided and the sawdust and millet were added to the buckets, a drill with a mud mixer was used to blend the dry ingredients. Then water was added until the mix was thick, pliable, and most of the ingredients were combined.

Following that, the whole bucket was emptied onto the bench and the remaining un-mixed material was hand mixed until it was uniform. I am told this is called wedging. I'm pretty sure what I was doing had no resemblance to actual wedging. At any rate it was mixed.

Then I pressed the clay into the forms I had made the day before. I used some scrap wood to pull across the top of the form. With a slight side to side motion this eventually left a pretty smooth surface. Smooth is not as much the point as it being free of voids that would allow heat to escape.

After a few hours the backs were taken off to let them dry faster. I also added some clay to the backs and pulled them with the scrap wood again to fill in several voids that remained after I molded them in the first place.

Note that I tried to lift the backs off. No go. This just pulled more clay out of the surface. I then took to hitting the bottom sideways to shear it loose.

Now to let them dry. Hope they don't crack! Once they get pretty dry I think I'll put them in the kiln at 200 degrees for several hours to see if we can dry them faster.

I have enough EPK for more. I am going to need another five pounds of Aluminum Oxide and Zirconium Silicate.