ferenc jakab on wed 31 may 00
doubting the problems
> Clayartists,
> Jocelyn McAuley has cautioned me that throwing sawdust into an electric
kiln will be
> like setting off a home made bomb, Cindy Strnad that the reduction will do
damage to
> the elements. I appreciate these words of caution but am still not
convinced. It is
> important to note that I am not going to 1200C or even 1000C, but only
500C, just
> above the lowest visible red.
Reid I don't know what will happen when you do this but 500C is above the
ignition point of wood or cellulose.
Feri.
Jean Todd on wed 31 may 00
doubting the problems
What is the difference between 500' and 1280' here? The flashpoint of the
sawdust and air mix is the critical factor here and that is well under 500'.
Also remember that the flash has nowhere to go but towards you when it
blows. Please do not do this thing.
Jean
"Lang may your lum reek"
E-mail mallyree@ix.net.au
----- Original Message -----
From: "Reid Harvey"
To:
Sent: Monday, May 29, 2000 2:32 AM
Subject: STILL throwing sawdust into an electric kiln, doubting the problems
> Clayartists,
> Jocelyn McAuley has cautioned me that throwing sawdust into an electric
kiln will be
> like setting off a home made bomb, Cindy Strnad that the reduction will do
damage to
> the elements. I appreciate these words of caution but am still not
convinced. It is
> important to note that I am not going to 1200C or even 1000C, but only
500C, just
> above the lowest visible red.
>
> Certainly it is not my choice to use an electric kiln, simply what is
available to me
> in this short time that I remain in West Africa. Jocelyn's caution will
make me move
> a little faster, getting the door closed quicker, but I'm still wondering
what it is
> about reduction that does damage to the elements. Can someone enlighten
me? Whatever
> it is I can imagine that the effect would be much more pronounced at 1200
than at
> 500.
>
> Thanks again,
> Reid Harvey
> Ceramiques d'Afrique
>
>
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Morris, Marlene F. on wed 31 may 00
doubting the pr oblems
> but I'm still wondering what it is
> about reduction that does damage to the elements. Can someone enlighten
me? Whatever
> it is I can imagine that the effect would be much more pronounced at 1200
than at
> 500.
> Thanks again,
> Reid Harvey
> Ceramiques d'Afrique
Hi there,
I'm very new to firing, just on the point of buying a kiln, so I wanted to
ask about this, too.
I just read this in Harry Fraser's book "The Electric Kiln" (1994):
"An important feature of Kanthal wire is that after firing, the wire builds
up a layer of aluminium oxide on its surface which protects the wire from
attack by harmful furnace gases. It takes two or three firings for this
protective layer to form and for this reason the initial firings of a new
kiln or one fitted with new elements should be test or biscuit firings
rather than glaze ones due to the much more corrosive nature of the gases
liberated in glaze firings. Also, exposure to reducing atmosphere will
remove the protective coating and the elements will then rapidly deteriorate
unless the coating is restored by an oxidising fire. This is why reduction
firings in an electric kiln should always be followed by at least one
'clean' oxidising fire. Even so, it must be repeated that reduction firings
significantly reduce element life."
Each book I'm looking at warns against reducing in an electric kiln, giving
the shortened element life as the reason.
If I wanted to reduce in a saggar in an electric kiln, would that also be a
problem?
But I wouldn't throw sawdust into the thing -- I value my skin too much for
that.
Marlene
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