Christopher M. Rose on sun 19 dec 99
Hello everybody,
Thanks in advance to anyone who can help me out with this
question. I often paint over glazes (usually shinos) with a
thin wash of red iron oxide. Mostly it comes out the familiar
brownish color we all know, but infrequently it comes out
a metallic coppery color that is highly reflective. I think this
is what glass blowers mean when they use the word 'strike'.
(It's really nice!)
Can anybody tell me how to get this effect reliably? Is there
a particular period of the firing that needs to be reduced? And/or,
does this require reduction cooling of some sort? I am firing to
cone 10 in reduction with gas and with wood.
Chris Rose
amateur potter in Baltimore
wishing for a little of the white stuff
Pat Colyar on mon 20 dec 99
Chris, I get this effect fairly reliably when using red iron oxide wash
on Wirt's Carbon Trap. We fire with about an hour of body reduction
starting at cone 010, then a light reduction all the way to cone 10.
It also depends on the correct application of the oxide wash: too thin
is just brown, too thick goes into metallic black, just right is
iridescent, very nice. We don't do any reduction while cooling stuff.
Good luck! Pat Colyar in grim, grey, wet Gold Bar, WA
Sara JH Ashodian on mon 20 dec 99
chris
im hopin for some of the white stuff here too!
many times i also paint with rio, although i do this first, then glaze with
shino over the rio markings, this also produces the effect you speak of
although im not sure i believe from my own results that it is due to the
concentration of the rio wash mixture
sara
nahant by the sea
--
Sara JH Ashodian
Sash Arts Studio
----------
>From: "Christopher M. Rose"
>To: CLAYART@LSV.UKY.EDU
>Subject: Iron oxide 'striking'
>Date: Sun, Dec 19, 1999, 12:01 PM
>
> ----------------------------Original message----------------------------
>
> Hello everybody,
>
> Thanks in advance to anyone who can help me out with this
> question. I often paint over glazes (usually shinos) with a
> thin wash of red iron oxide. Mostly it comes out the familiar
> brownish color we all know, but infrequently it comes out
> a metallic coppery color that is highly reflective. I think this
> is what glass blowers mean when they use the word 'strike'.
> (It's really nice!)
>
> Can anybody tell me how to get this effect reliably? Is there
> a particular period of the firing that needs to be reduced? And/or,
> does this require reduction cooling of some sort? I am firing to
> cone 10 in reduction with gas and with wood.
>
> Chris Rose
> amateur potter in Baltimore
> wishing for a little of the white stuff
Hank Murrow on mon 20 dec 99
>----------------------------Original message----------------------------
>
>Hello everybody,
>
>Thanks in advance to anyone who can help me out with this
>question. I often paint over glazes (usually shinos) with a
>thin wash of red iron oxide. Mostly it comes out the familiar
>brownish color we all know, but infrequently it comes out
>a metallic coppery color that is highly reflective. I think this
>is what glass blowers mean when they use the word 'strike'.
>(It's really nice!)
>
>Can anybody tell me how to get this effect reliably? Is there
>a particular period of the firing that needs to be reduced? And/or,
>does this require reduction cooling of some sort? I am firing to
>cone 10 in reduction with gas and with wood.
>
>Chris Rose
Dear Chris; I too have observed that many shinos exhibit this irridescence
with Fe brushed on the glaze. It seems to be stronger in those glazes with
soda ash or other solubles. Cryolite will promote this as well. seems to be
more prevalent on shiny surfaces. I don't think it is 'striking' based on
my experiences in glassblowing. Good Luck, Hank in Eugene
Dale A. Neese on tue 21 dec 99
I have had pretty good results by using a sieved fireclay slip on the
leather hard ware under the Shino.
Dale Tex
Hank Murrow on mon 27 dec 99
>----------------------------Original message----------------------------
>Chris, I get this effect fairly reliably when using red iron oxide wash
>on Wirt's Carbon Trap. We fire with about an hour of body reduction
>starting at cone 010, then a light reduction all the way to cone 10.
> It also depends on the correct application of the oxide wash: too thin
>is just brown, too thick goes into metallic black, just right is
>iridescent, very nice. We don't do any reduction while cooling stuff.
>
> Good luck! Pat Colyar in grim, grey, wet Gold
>Bar, WA
Dear Pat; I bet if you could manage to get the soda ash out of Wirt's
Shino, you would lose the irridescence as well. My theory is that soluble
fluxes are responsible for irridescence in glazes when metallic oxides are
brushed over them. See if you can test this. Regards, Hank
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