I.Lewis on sat 29 jan 00
------------------
In a posting about oilspot glazes David Orser mentions the sighting of a =
green
flame
=3C...firing neutrally, with as little flame as possible... a
light green flame at the end of the firing did not seem to be a problem.=3E
I have seen this sort of thing and put it down to copper collecting on kiln
furniture or in the fibre and volatilising at the next firing. But I think I=
am
wrong and that it may due to Boron or a Boron compound which is coming out =
of
the kiln. Are there any other opinions or sightings of this colouration in
flames which issue from the flue or ports.
Inquisitive as usual,
Ivor Lewis.
Theodore Banton on thu 3 feb 00
At times I believe that this can be caused by zinc that is released in the
firing
Frank Bosco on fri 4 feb 00
Green flame is a neutral, or oxidizing flame. Get the green flame, get no
reduction.
Jonathan Kaplan on sat 5 feb 00
>----------------------------Original message----------------------------
>Green flame is a neutral, or oxidizing flame. Get the green flame, get no
>reduction.
We have consistantly fired at a .65 oxyprobe reading with a beautiful
bright green flame from the side peeps as well as the door peeps. Our
reduction is perfect throughout the load: copper reds are bright, boron
containing glazes are as they should be with no zits or pinholes, and the
old trustworthy matte glazes are ringers.
Just thought I would fuel the fire, so to speak.
Jonathan
Jonathan Kaplan
Ceramic Design Group LTd/Production Services
PO Box 775112
Steamboat Springs, CO 80477
(970) 879-9139 voice and fax
http://www.sni.net/ceramicdesign
UPS: 1280 13th St. Unit13
Steamboat Springs, CO 80487
Dannon Rhudy on sun 6 feb 00
>
>We have consistantly fired at a .65 oxyprobe reading with a beautiful
>bright green flame ...Our
>reduction is perfect throughout the load: copper reds are bright,.....
I weigh in with Jonathan here. I often have a bright green flame
during firing, and it has NOT meant that the kiln was not in
reduction. I've not an oxyprobe, but I DO have consistently
red reds, great shinos, etc. Green flame or no.
regards
Dannon Rhudy
potter@koyote.com
Debby Grant on sun 6 feb 00
I too have always felt that we got the best reduction when the flame
coming out of the peep holes and dampers of our old Alpine up draft
kiln was green. This definitely was not an oxidation or neutral firing.
Debby Grant in NH
John K Dellow on sun 6 feb 00
Jonathan Kaplan wrote:
>
> ----------------------------Original message----------------------------
> >----------------------------Original message----------------------------
> >Green flame is a neutral, or oxidizing flame. Get the green flame, get no
> >reduction.
>
> We have consistantly fired at a .65 oxyprobe reading with a beautiful
> bright green flame from the side peeps as well as the door peeps. Our
> reduction is perfect throughout the load: copper reds are bright, boron
> containing glazes are as they should be with no zits or pinholes, and the
> old trustworthy matte glazes are ringers.
>
> Just thought I would fuel the fire, so to speak.
>
> Jonathan
Hear hear to that Johnathon , If this old flower pot man gets a
green flame at a spie hole then its means badly flash or even
black heart in a load of terra-cotta !. To me lovely pots but to
my wholesale customers "seconds" :(.
John Dellow "the flower pot man"
Home Page http://www.welcome.to/jkdellow
http://digitalfire.com/education/people/dellow/
ferenc jakab on sun 6 feb 00
I always thought green flame was a sign of copper in the firing. I know
copper stays in kilns a long time after because it fumes into the bricks. I
had a firing ruined once when another ceramicist used copper in a kiln which
was supposed to be kept free of copper.
Feri.
I.Lewis on sun 6 feb 00
------------------
I accept Frank Bosco=92s comment as being true if he is writing about the =
flame
which issues from the tip of the burner. I was writing about the burning off=
of
the residuals of the fuel as they leave the flue or chimney. My initial =
reaction
when I first saw this (1989)from the kiln was that the copper glazes I was
reducing were volatilising. As it persisted I considered it to be due to
residual copper which might have collected in the flue. It was reading the =
post
which mentioned the green flame and connecting it with the recipe which was
given that triggered the thought of boron. The glaze had no copper, but it =
did
contain boron. Green flame is a qualitative test for the Boron ion.
Continuing to be inquisitive,
Ivor. A Happy and Prosperous Year of the Golden Dragon to every one. Hope =
you
saw the eclipse.
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