David Hendley on fri 30 jul 99
I think the best way to get rid of solids from the studio sink, left over
bits of glaze tests, and other such 'wastes' is to add them into the mixture
the next time you make your claybody.
The main ingredients in stoneware glazes are feldspar and flint, which
most claybodies already include, and of course, the residue from the
wash-up sink is just your claybody, anyway.
I use 2 cups per 100 pounds of clay. This is such a small percentage
that the results are absolutely not noticable. Even if you add 2 cups
of a high-iron tenmoku glaze to a white stoneware body, it's still not
enough to affect the color.
Colorant ingredients from glazes are so diluted as to be insignificant.
I figure if you used only a manganese glaze for the entire 2 cups,
your claybody would have added manganese in the neighborhood
of .015% (.00015). Does anyone consider manganese at this
concentration in clay a health hazard? Of course, if you had some
manganese glaze it would likely be only a small part of the sludge, say
10%, and the total would be maybe .0015% (.000015) manganese in
the clay. If you used 100% of a typical cobalt oxide glaze as your 2 cups,
your clay would have added cobalt oxide of about .0025% (.000025).
This solution to the problem
recycles the material,
creates no waste,
fires it into an inert state,
and uses no extra energy.
Sounds like the ecological ideal to me and
another good reason to make your own claybody.
The last thing in the world I would do is call 'my local disposal
authorities',
but then again I try to have as little to do with governments and authorities
as possible ('Hello, we're from the government, and we're here to help you').
And this certainly doesn't apply if you have any truly hazardous materials
such as uranium on hand.
David Hendley
Maydelle, Texas
hendley@tyler.net
http://www.farmpots.com
At 05:03 PM 7/29/99 EDT, you wrote:
>----------------------------Original message----------------------------
>At 09:28 AM 28/07/99 -0400, Joan Woodward wrote:
>>----------------------------Original message----------------------------
>>Gavin:
>>
>>I bite. What's the responsible way to dispose of the sludge? Is it toxic
>>in sludge form? If I could pipe from my clay sink down into a crawl space
>>and wash my waste water down the pipe, would I be contaminating my house
>>from the accumulated gunk underneath? Thanks.
>
>Hi Joan,
>
>It really depends what material is in it. If it is contaminated with
>colorant, like from a black body colored with manganese dioxide, then it
>may be a bit of a different problem than for an ordinary clay/feldspar
>body. For the latter, it is really just slightly modified clay, not very
>different from riverbank clay. That can be disposed of wherever the
>siltation will not be troublesome, as for instance under your house,
>although you might want to be careful about dumping water in the wrong
>place, for fear of rotting or clogging up your drainage. Dumping it down
>into a leaching field is not a good idea, as the fine clay will eventually
>clog up the pores in the leaching bed. Similarly, dumping down a drainpipe
>in the city is not a good idea, as the clay may accrete in the pipes, and
>be difficult to clean out. So, dewatering, by settling and decanting,
>followed by dumping the damp sludge in the garden, or in a landfill is
>probably the best bet.
>
>If there are toxic contaminants, as from glaze colorants and modifiers, the
>problem is more complex. In a previous discussion on clayart, we discussed
>what one might do with a small amount of Uranium salt. The answer was that
>there is no really good way to do this. The legal way is to get it into
>the hands of a licensed disposal firm, I suppose. Then they can deal with
>it, not always well. The responsible thing is probably to fire it into a
>good glass, and dispose of that in a proper landfill. As a practical
>matter, what do we do with the sludge from our glaze sink? One answer is
>the sludge glaze. Use it as part (or all) of a dark glaze. Some may think
>this rather too much of a good thing. Also, it must be tested each batch,
>to see what kind of glaze properties you get, so this is not a trouble free
>solution.
>
>We are dealing with the same problem as is posed by mining, only on a very
>much smaller scale. The mining industry has not been a stellar example, as
>leachates from mine operations are a significant pollution problem. Our
>quantities are orders of magnitude less, but the problems are the same.
>
>I guess the answer is best phrased in do's and don't's:
>
>1 Do reduce, reuse, recycle.
>2 Do separate from clear water.
>3 Don't flush it down the sink.
>4 Do segregate toxics from non-toxics, where possible.
>5 If non-toxic, dispose of as you would ordinary clay or dirt. Try not to
>make a dust hazard.
>6 Don't let it dry and sit in a lump where it might make a dust hazard.
>When contaminated with toxics:
>3 Don't put it on your garden or elsewhere where it would contaminate the
>soil.
>4 Don't put in with ordinary refuse, unless instructed to do so by the
>local authorities.
>5 Do ask your local disposal authorities what to do with the residue, and
>follow their instructions.
>6 If they don't know what to do either, try firing it into a block. Use
>as a doorstop.
>
>That's about as good as I can do.
>
>Gavin
>
| |
|
