Made my own terracotta from backyard dug local clay and a Weber grill. Turns out the dwarves taking like a week to dig clay and make a pot is about right, realistically!
1) Clay slaked in water and floating debris scooped out with a sieve (photos come from different scale batches:
2) Later, clay is poured off leaving heavy debris behind:
3) Clay is allowed to drip through muslin to dry as much as possible for a day or two:
4) Then the remainder of the drying happens in the sun once it's solid enough to stay on a board:
5) Built siome shittily made trinkets as test items (the non-bowls are all supposed to be mediocre incense holders)
6) Left to get bone dry (not only dry looking but room temperature to the touch = no evaporation anymore):
7) Fired in a grill. First left around the edges of the food rack while the coals warm up. Then moved slowly to the middle. Then after awhile laid on top of the coals. Then later surrounded with coals. Then even later more coals added and air blown in, let soak in heat for half an hour at least (this method made them bright orange hot throughout, about cone 04 I'm guessing, maybe a little higher. Something like 2,000 degress Fahrenheit, low earthenware temps). Allow to cool down naturally slowly.
In a real kiln you wouldn't get those black spots, which are from lack of oxygen where they touched coals, causing iron in the clay to reduce to an oxide that's black and hard to get rid of later. Red classic terracotta color, on the other hand, being those same iron impurities oxidizing into a different iron compound, when they have enough air. High quality stoneware (fire clay, as you know from DF) clay doesn't have the iron impurities and so turns out white, and can withstand much higher temperatures, which are enough to vitrify it without melting it, making it watertight and stronger.
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Topic: Random Things you drew/shopped/made/etc. (Read 1348396 times)