Now, If you are still looking at this mess, let me explain. It's all about working against gravity! The photo above is the very top of the rectangle with a new slab of leather hard clay just placed on the top. The clamps and strips of wood are holding the sides straight, so it won't sag anywhere. You can see the supports on the sides flaring up and outward towards this top slab. Right now the edges of these supports are covered with wet paper toweling so they will stay damp as the new side panels will be attached to them, connecting to the top panel. Here in the picture to the left you see the photo repeated but with a new side panel attached on the right side. I've placed a brace against it to hold it in place against the braces beneath so it will attach itself as it dries. As you can see, it's quite a procedure working against gravity getting the side panels to attach themselves correctly and solidly to the edge of the top slab and the braces beneath.
In construction terms, I've just placed a sheet of drywall, the top up against the ceiling, braced there against the studs with a brace, which will hold it there in place while I calmly screw the drywall screws into the studs.
It has become clear to me that I must do things differently in the future. I will have to work out a way to building the next rectangles in two parts. One being the top half upside down and separately, the bottom half, normally from the bottom up. That way the two end slabs will be straight and level. I build up the bottom part to about three quarters of the way up and top part one quarter of the way, Then when quite dry, lift the top half up, turn it over and place it onto the three quarters high bottom piece. Then I won't need to work against gravity like I did with this one. It would make things much easier and I'd say also a lot quicker.
Thanks again for letting me process and work things out here. Writing this down often helps make things a lot clearer. It's also kind of embarrassing because when a solution comes, it all seems so obvious and simple. Like why did I not think of that before? Thanks for your patience.
Now I've got to get this one done and begin this adventure of building the next one.
but sometimes the paperwork
Werner von Braun