Back to Ganoksin | FAQ | Contact

Reduction Atmosphere in Kiln


#1

To get a reduction atmosphere in a kiln you can use pipe nipple and 2
caps. You can use either fine steel wool inside the caps, or can use
fine charcoal to absorb the oxygen. Some graphite on the threads
will make it easy to open. John Burton


#2

In my previous life–as a potter–people sometimes tried to produce
a reduction atmosphere in an electris kiln (to get copper reds, for
example) by feeding moth balls into the kiln as it heated. Word was,
it worked, but destroyed the elements. What I am wondering is
whether, in a closed container in a kiln, moth balls would work
better or worse than charcoal or carbon. Also, would they be toxic?
We never used to worry about anything but lead, in the ignorantly
blissful old days.(I’m also wondering, more from habit than
intention, whether a copper-glazed pot, in a container with carbon
sheets, would come out red.)


#3
    To get a reduction atmosphere in a kiln you can use pipe
nipple and 2 caps. You can use either fine steel wool inside the
caps, or can use fine charcoal to absorb the oxygen. Some graphite
on the threads will make it easy to open. John Burton 

Great idea. I suspect that it might be suggested that this not be
air tight. Am I wrong? I would suspect that if one were to wrench shut
a nipple with two end caps the expanding air inside might produce
enough pressure to allow a heat weakened bottle to burst.


#4

Hello, Re: Noel Yovovich’s question:

 What I am wondering is whether, in a closed container in a kiln,
moth balls would work better or worse than charcoal or carbon.
Also, would they be toxic? 
Hopefully, John Burgess can jump in on the chemical reactions and

what gases might be released from putting mothballs in a hot kiln.
Mothballs as we know them (unburnt) are usually napthalene (NAP).
Exposure to NAP can occur in the home and workplace. Remembering
that the dose makes the poison, exposure to modest amounts of NAP is
toxic to people. Ingestion and inhalation can cause severe toxicity
in humans, especially infants. There are several reports of infants
becoming ill after being covered with blankets that had been stored
in mothballs. Here’s a website that can go into more detail:
http://risk.lsd.ornl.gov/tox/profiles/naphthalene_f_V1.shtml Bottom
line: don’t use NAP mothballs where people could continually be
exposed to the vapors.

Judy in Kansas, where the weather is nearly balmy - MOST un- wintery!

Judy M. Willingham, R.S.
Biological and Agricultural Engineering
237 Seaton Hall
Kansas State University
Manhattan KS 66506
(785) 532-2936


#5
        Hopefully, John Burgess can jump in on the chemical
reactions and what gases might be released from putting mothballs
in a hot kiln. Mothballs as we know them (unburnt) are usually
napthalene 

G’day. You rang Modom? I read the citation on naphthalene for
which Judy kindly provided the URL. I came to the conclusion that
it is so academically oriented and jargon ridden that it isn’t a lot
of use to us ordinary folks, but that certainly isn’t Judy’s fault!
Now I’ll supply a bit of jargon! Firstly in chemical terms
naphthalene is an aromatic compound. Although it does have a strong
aroma, that isn’t quite what is meant by the term in chemistry; it
has to do with a certain type of molecule containing carbon and
hydrogen (and other elements like nitrogen sometimes) which is based
on a hexagon. Benzene is the basic one, C6H6 and it’s molecule can
be visualised by drawing a hexagon, putting CH (Carbon, Hydrogen) at
each corner. Toluene (used to be used in vehicle fuels) is another
where one of the CH’s is exchanged for CH3, Even TNT is an aromatic;
there are dozens of them. It has been shown that very many of the
aromatics of this type are powerfully carcinogenic; all those I have
mentioned are. It seems to me that the aromatics like naphthalene and
even the modern variety are to be avoided if at all possible.
Anything of the sort when strongly heated will certainly produce
other aromatics.

I strongly suggest that the object to be heated in a kiln might best
be placed in a fireproof box with a few bits of charcoal. Certainly
keep naphthalene out of it!

What I don’t understand however, is why, in this age, naphthalene is
still sold and used for moth protection; for there are other things
far less toxic - and less smelly. Another thing I don’t understand is
that an elderly neighbour of mine always positively reeks of
naphthalene due to his habit of putting a good handful of mothballs
in every cupboard, drawer and closet, and putting several with every
winter woolly, blanket, coat, etc when he folds them away in late
spring. Yet the old blighter is surprisingly healthy! Well, not
entirely what you wanted to know perhaps, but there is a ha’porth
for you to ponder upon. – Cheers for now,

John Burgess; @John_Burgess2 of Mapua Nelson NZ