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fake flashing with soda ash

updated tue 30 nov 99

 

tgschs10 on sat 27 nov 99

I was lurking a few weeks ago when the list was a buzz with talk about "fake
flashing" using soda ash. I just open my ^10 reduction fired kiln last
evening. THANK YOU CLAYATERS - SPECTACULAR - just what I've been looking
for. I need to do a ^5-6 oxidation fire and I remember some of the folks had
either fired with soda ash in oxidation or were planning to fire in
oxidation, can I expect color in oxidation as well? I really put the soda
ash on heavily - used several coats; the result were light and dark
brown-tan areas; does anyone know if the color relates to the heaviness of
application and if so how?

Tom Sawyer
Orlando, Florida
tgschs10@classic.msn.com

Cindy Strnad on sun 28 nov 99

Tom S,

I've been experimenting with the soda ash firing at ^6, and yes, you do get
color. So far, I've only applied it over my usual iron oxide wash, but there
is a definite difference between with/without, and also a difference where
the EPK/Alumina wads protect the surface.

In places where the soda ash solution has gotten onto the surface to be
glazed, I've noticed it's hard for the glaze to stick--thins it out to near
water consistency. Then, when I do get it applied thickly enough, it turns
my beautiful blue glaze to a gorgeous turquoise/teal. Soda ash is nothing
but sodium, according to Insight, so I'm going to try some experiments with
adding it to my glaze.

For some reason, the solution dissolved the glue holding my hake brush
together. I wouldn't have expected that, and I suppose it may have just been
the hot water. Hot paraffin doesn't affect the hake brush that lives in my
electric frying pan/wax melter, though. (?) Maybe the glue is water soluble
but not oil soluble.

Thanks to all of you (Tom, Dannon, and others) who answered my questions
about this neat new trick. I'm excited about it. It gives the unglazed
portions of my work a nice finished (but not over-refined) look. I like it.

Cindy Strnad
Earthen Vessels Pottery
Custer, SD

The Brinks on sun 28 nov 99

Tom- I'll be watching for answers on this one too regarding the ^6 use of
soda ash. I put just one good application on the exterior of a bowl and
fired to ^7 last week, and though I could see it had slightly darkened the
clay, it didn't have that fluxed look. So next time I will use several
coats. Glad you had a great firing with the ^10 reduction!

Ann Brink in CA

At 10:38 AM 11/27/99 EST, you wrote:
>----------------------------Original message----------------------------
>I was lurking a few weeks ago when the list was a buzz with talk about "fake
>flashing" using soda ash. I just open my ^10 reduction fired kiln last
>evening. THANK YOU CLAYATERS - SPECTACULAR - just what I've been looking
>for. I need to do a ^5-6 oxidation fire and I remember some of the folks had
>either fired with soda ash in oxidation or were planning to fire in
>oxidation, can I expect color in oxidation as well? I really put the soda
>ash on heavily - used several coats; the result were light and dark
>brown-tan areas; does anyone know if the color relates to the heaviness of
>application and if so how?
>
>Tom Sawyer
>Orlando, Florida
>tgschs10@classic.msn.com
>
>
e-mail billann@impulse.net

Hank Murrow on sun 28 nov 99

>----------------------------Original message----------------------------
>I was lurking a few weeks ago when the list was a buzz with talk about "fake
>flashing" using soda ash. I just open my ^10 reduction fired kiln last
>evening. THANK YOU CLAYATERS - SPECTACULAR - just what I've been looking
>for. I need to do a ^5-6 oxidation fire and I remember some of the folks had
>either fired with soda ash in oxidation or were planning to fire in
>oxidation, can I expect color in oxidation as well? I really put the soda
>ash on heavily - used several coats; the result were light and dark
>brown-tan areas; does anyone know if the color relates to the heaviness of
>application and if so how?
>
>Tom Sawyer
>Orlando, Florida
>tgschs10@classic.msn.com

Dear Tom; I believe soda flashing to be very analagous with shinos. That
is, one should give them lots of early reduction, followed by a cleaner
fire to the end of the fire, and a soak in Oxidation around 2000F during
the cooling. I would suggest that you do a C/5 firing following such a
procedure and see how it works out. As to thickness, I have found that the
flashing is most orangy where it is thinnish, at least on clean bodies.
Hope this helps. Hank in Eugene

Dannon Rhudy on mon 29 nov 99

At 10:38 AM 11/27/1999 EST, you wrote:
>----------------------------Original message----------------------------
>....my ^10 reduction fired kiln last
>evening. THANK YOU CLAYATERS - SPECTACULAR - just what I've been looking
>for. I need to do a ^5-6 oxidation fire .>
>...............................................................

Try the oxidation - works in some cases, if the wash is thin. In general,
thinner is better for that orangey-look. The thicker the soda ash, the
more likely to just get a gloss coat on the clay, not much color. In
my experience. You don't say what clay you were using - I like it best
on porcelain, but it can also make very rich browns on stonewares.

My purpose in using the soda is to get the flashing, and not a "glazed"
look to the clay. For those expecting it to glaze, it has to go on thick,
and then is very likely to crackle. If only the gloss is wanted, then
might be better to use a clear glaze, eh?

Regards,

Dannon Rhudy
potter@koyote.com

Tom Buck on mon 29 nov 99

Why reduce? I gather from my reference texts that Na2O (from Na2O.CO2)
will not be affected by CO (or H2) but will flux the alumino-silicate of
the claybody and form a surface glaze which will be "toasty" if some iron
oxide is present. This reaction will occur in most kiln environments. When
I do it at C6 ox in my electric, I get "toast".
til later. Tom B.

Tom Buck ) tel: 905-389-2339
(westend Lake Ontario, province of Ontario, Canada).
mailing address: 373 East 43rd Street,
Hamilton ON L8T 3E1 Canada