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rusty kiln wash disposal

updated wed 5 apr 06


LaurieJean gombar on mon 3 apr 06

Upon further look at the kiln wash I have (equal parts by volume
alumina, epk, sillica) that has a rusted roller in it- I am leaning
towards tossing it. I took the leap and called someone in the waste
management dept asking what I should do with it when internet searches
came up with nothing. He reccomended I dry it out and dispose of it in
the trash. Though in earlier searches of clayart archives I read
something about this stuff just being spread around anyway once the bag
or whatever it is in gets broken. I have read about ppl firing glaze in
order to dispose of it- thoughts of this sends my head reeling about how
I would go about doing this.
There is only about a gallon of this mixture- do I put it in a paint can
instead of a bag?

If I kept it somewhere in the corner, would it ever be able to be made
up into a glaze in the future? -other ingredients added to make
something out of it instead of tossing it? Though would it later be
something I would toss anyway like Primalmommy had her big purge of

I would appreciate more feedback on my little problem. Thank you in
{Mom of toddler- potter wannabe plodding along at a comatose turtles

Bonnie Staffel on tue 4 apr 06

I have found that if you pour your liquid material into a container of kitty
litter, it should dry into a disposable condition.

Bonnie Staffel
DVD Throwing with Coils and Slabs
DVD Beginning Processes
Charter Member Potters Council

Richard White on tue 4 apr 06

I'm not an expert on any of this (yet), but here is the logical progression
of my thinking on your question...

1) Disposal as a hazardous waste: Nothing hazardous about it. The alumina
is aluminum and chemically-bound water, common and benign elements. The
dust causes lung disease if inhaled, but otherwise not toxic. The silica is
finely ground sand, almost like that at the beach - children play in it all
summer long. The dust causes lung disease also, but not toxic in and of
itself. The EPK is clay, no worse than in your garden, just pure. Again,
dust is its worst problem. And now you've contaminated it slightly (for
purposes of kiln wash) with some iron oxide. Rust is everywhere and is not
killing anybody? So that would be why your hazmat guy wasn't worried.

2) Use as a glaze component: That will take some chemistry experiments.
Many glaze recipes contain various amounts of alumina, silica, and EPK, but
in very different proportions than your equal parts. To use this in a glaze
mix, you will first need to determine how much material there is in the
wash mix, which means determining its specific gravity. If you have a
precise 100 ml measuring container, you can weigh it on your beam balance
and subtract the weight of the empty container. 100 ml of pure water is 100
grams, so whatever the excess mass of the wash mix is equals the mass of
the components in that 100 ml of slop. Let's say it weighs 160g. 100g of
that is the water, so the stuff in the water must be 60g. You said it was
equal parts (which I assume was originally done by mass, not scoopsful...),
so that suggests 100ml of the slop contains 20g each of alumina, silica,
and EPK. Now you just have to adapt a recipe that uses all three
components, but deduct 20g each to account for what's already in 100ml of
wash mix. Use 100ml of the well-stirred wash to start mixing your glaze
batch and then add plain water as needed to bring it to the proper
consistency. Now you only need to decide what the traces of iron oxide will
do to the color and fluxing of the glaze. That's what test tiles are for...

Anybody else out there who could set me straight is welcome to... ;-)


John Post on tue 4 apr 06

There is nothing in this mix that is even remotely toxic to the environment.
BTW they line landfills with clay to keep the real toxics from seeping
out...not that this always works.
I personally would dig a small hole in my backyard and pour this stuff
in it. Then put the dirt back in over the top.
You could also dispose of this via the garbage collection at your
house. I would just dry it out first, by leaving the bucket lid open
for a while.

John Post
Sterling Heights, Michigan

>Upon further look at the kiln wash I have (equal parts by volume
>alumina, epk, sillica) that has a rusted roller in it- I am leaning
>towards tossing it.

LaurieJean gombar on tue 4 apr 06

Thanks all for your responses off and on list.... This makes me feel so
much better and to think I wasted hours fretting about this issue and
trying to come up with a solution that did not cost me a bunch of
>. I personally would dig a small hole in my backyard and pour this
stuff in it. Then put the dirt back in over the top. ____