I have asked The King of Random (and The Boy Wonder) a couple of times to build a kiln to fire his clay bricks. Yesterday they tried barbecuing homemade pottery:
From what I have read, the bricks need to maintain over 1,000°, and glow red. The Boy Wonder went from warming the pots by a fire to covering them in briquettes. He used a shop vacuum as a bellows and added a quarter bag of briquettes at a time. People commented:
1. He needed to maintain the temperature evenly.
2. He should have "scored and slipped."
3. He needed to use refractory bricks to keep the heat in.
I never took ceramics. You scratch the clay before adding another piece. Slipping is reducing clay to a watery mess and you put that on the scored clay before you add more. TBW said you needed to make the clay evenly thick, but did not seem to do a very good job with his fingers. I thought a tortilla press would have worked.
This page recommends a rolling pin [and explains scoring and slipping].
From what I have read, uneven thickness contributes to cracking, but that page shows a sculpture, not a tile, so it is completely uneven. It sounds like TBW needed to add briquettes gradually and keep the air supply steady.
When The King of Random made a clay brick, people asked about using his backyard foundry to fire the clay. People said it would not work, but
made his own kiln. It looks like an upside-down backyard foundry.
I ordered this:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
I wanted to make sure that I had the correct ratio of water to cement. It seems the foam ratio determines the characteristics, not the success rate, so I will worry about that later.
I bought a loaf pan from the dollar store and another can of shaving cream. I had not realized that I did not use the entire can last time, so I made sure to shake it and try again. I used a quick-release clamp to hold down the button. I also had the can sit in hot water, because last time the can was cold and seemed to have
Quote:
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When firing without a kiln, it may help to pre-dry you clay pieces in a kitchen oven set to 190 degrees F. With a kitchen oven, the pots are dried by "baking" below the boiling temperature of water for several hours. I set the oven to 190 F. This is NOT firing the pots, but it dries them so they can be fired in an outdoor bonfire or pit firing with less breakage caused by steam explosions.
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https://www.goshen.edu/art/DeptPgs/rework.html
Our oven does not work, but I have a toaster oven, although listening to it tick every second, and then dinging and turning off after fifteen minutes was annoying. Several hours?
Uh...
I would not have tried to run this while I slept. I only got 45 minutes. I doubt the toaster oven maintains much heat, but I left it alone until morning.
I found it curious I only saw this mentioned once, but the guy on Youtube that does not seem to know what he is doing, and does not seem to have successfully made anything mentioned keeping the surface damp as it cures, like you are supposed to with concrete.
I am not sure how often you are supposed to do that.
The top feels dry, but dented when I tapped it.