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Re: [teacherartexchange] stinky clay


From: Marvin Bartel (marvinpb_at_TeacherArtExchange)
Date: Wed Oct 12 2005 - 18:21:37 PDT

> Anyone have a hint on what to add to a bucket of recycled clay that smells
>to make it not "smell" (sulphur smell)? Thanks. San D

I have had students that have a strange sense of humor. Did your students (as a prank) bring some sulphur from chemistry class or perhaps an egg and put it in the clay? Naturally smelly clay becomes more plastic and may work better without cracking and have more green strength when it dries. I have actually added small amounts of mashed potatoes to clay to feed the bacteria for plasticity, but I would never recommend adding garbage like this to a school clay. It does get stinky and may be unhealthy.

Many people in various cultures eat clay. "To counteract toxins and poisons, the Aymara of Peru made a neutralizing clay dip for feral potatoes that belong to the poisonous nightshade family."
Dietary clay is heated hot enough to kill any micro-organisms in the clay. Many of the pills we take use clay as the binder and filler.

As is, our normal classroom rework often contains E-coli bacteria, but nobody to my knowledge, has gotten ill from it. Do not eat it without first sterilizing it. My ceramics prof also told us it is possible to get parasites by eating unsterile clay parasites. I had one student with an allergic reaction the molds in clay. She had to change courses.

Here are a few ideas (if you are still reading) that may reduce the stink if it is naturally occurring bacterial growth.

1) You might try a bit of very diluted bleach as a preventative.
2) Leaving the container open sometimes works. Air and clay bacterial are not friends. It also helps prevent the smell from accumulating inside the container.
3) Dry it out until time to use it. Then place dry pieces, any size, in water overnight and it will be soft by morning. Do not stir until it is all slaked. This works with bone dry clay. Leatherhard clay does not slake well.

4) For smelly clay, I suppose heating clay to 250 or so would sterilize it and might keep it from getting smelly when it is softened again.


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