I’ve been firing a lot of clay work recently. Here is a trip through the process with two different loads.
First off, remember the army of little figurine creatures recently featured in Quite a Gathering? They were fired and I unloaded them – they will now need glazing and another firing.
Next, I loaded the kiln with tiles I had just glazed. No objects in this load, just tiles, so there are a lot of shelves. In a glaze load, the items cannot be stacked or touch each other – in a bisque load, they can. So a glaze load can accommodate fewer items.
You can look through the sequence in the photos and see how each firing will be loaded differently, depending on what’s going into it. The kiln shelves are not attached to the kiln itself but stand on stilts. The stilts come in different sizes to fit the objects being fired.
There are also shelves of varying sizes. I have three full shelves and two half shelves. One full shelf is set on stilts at the bottom of the kiln and always stays there – the bottom of the kiln does not have objects set upon it.
The shelves are covered with a substance called kiln wash – it’s brushed on when wet and dries to a hard coating. The purpose of kiln wash is to provide a peel-off surface in case a glaze runs – without kiln wash, the object would stick to the shelf itself rather than being able to be lifted (although with a bit of white stuff now stuck to it which cannot always be scraped away that easily – but it’s better than a ruined kiln shelf, which is expensive).
The kiln will run for 6-8 hours, depending on how things go. I can remove items from it the next day.
So now you can see why I think the kiln is a revolving door – clay pieces go in and out and in and out and…