Primary Air and Stoke Hole Covers

Now that the decision has been made to fire, there are all sorts of things that can no longer be ignored, like having stoke hole covers and doors. Unfortunately, it has been rather rainy lately, making the casting of the primary air a bit sketchy, so I reverted to my original plan for the primary air, for now. Later, when it’s dry weather again, I think I’d like to cast it. For now, the air looks like this:

Those are the same shelves I used to line the floor of the kiln and for grate bars, trimmed down to 69cm to fit in the doorway. The supports on either side are left over scrounged hard arch brick slabs, 23x23cm. With 4 or 5 of those shelves spanning the gap, the center support is probably not even necessary, but just in case… 

There are some more left over scrounged bricks that I am thinking about for the door, until I get the castable idea more developed. I’ll play with those tomorrow and post pictures.

I put together a form to make stoke hole covers this morning as well, and so far everything looks good. Here’s the form and slabs after I removed the outside frame, then some slabs shown in place just like how they’ll be during the firing. Everything seems to fit pretty tightly. The slabs are semi light castable, about 7cm thick, and 29x25cm wide. It will be interesting to see if/how well they hold up.

I think that I will bind them with angle iron on two sides vertically, with the angle iron extending a few inches beyond the bottom, so that the slabs will sort of stand on little legs, leaning against the hole. Then they can just be tilted back and forward again during stoking. If the seal ends up being too loose, then some fiber gasket will be cemented to the stoke hole bricks.

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