Lili Krakowski on fri 4 may 12
I really am not being disputatious, but I stand--actually sit--by what I =
=3D
said. =3D20
Which is: " The basic composition of glazes, the chemical interactions, =
=3D
the effect of heat and so on are the same no matter how you fire. The =3D
difference between fuel burning fire, and electric fire is about the =3D
same as that between yeast and baking powder/soda baking."
Wyndham writes: "Lili, unless I totally misunderstand your post, this =3D
part of your post
has not been my observations in the 25 yrs of firing both electric and
gas kilns. In a fuel kiln, you introduce another material into the glaze
firing, the fuel itself. The wall thickness of a kiln can and will
effect to some extent the results, as well as other factors time does
not allow [me] to elaborate."
I did not intend to imply in any way, no matter how vague, that how one =3D
fires makes no
difference. Of course it does. I thought that the bit about yeast and =3D
baking powder/soda
said that.
IMO iron is "only" an additive--whether introduced independently or =3D
supplied by a ferruginous clay.
And iron does THIS in neutral fire, THAT in reduction. Something yet =3D
other
when the fire see-saws from oxidation to reduction and back as in a =3D
woodburning kiln.
And several other "additives" react differently in altered firing =3D
circumstances. Some can
be lovely, some horrid. (Thinking copper and chrome)
My point was, is, that the actual composition of a glaze is the =3D
overarching determinant. The firing=3D20
method is secondary.=3D20
=3D20
Returning to cooking. If I want acid for a marinade there is lemon =3D
juice, tamarind, pomegranate,wine, vinegar,
and no doubt stuff I forget. The important thing to understand is why =
=3D
acid is being added.=3D20
And whether the marinated food is steamed, boiled, baked, grilled, =3D
roasted, fried, the major impact on the food
is from marinade plus heat-over-time.
In glaze we add fluxes to alumina and silica. We choose our fluxes. =3D
Each flux contributes something...more, or less.
Some on this list consider barium, strontium, calcium, to be =3D
interchangeable, some do not.
We all agree that --along with magnesium--these are alkaline earths. =3D
Fluxes.=3D20
The alkalis--soda, potash, lithium-- are very active fluxes. We all =3D
agree they have strong impact on color. =3D20
If one is to understand glaze one has to understand what the materials =3D
do, and how they act and interact.
Firing is secondary. =3D20
Not negligible, not unimportant. But secondary, IMO, to glaze =3D
composition.
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