Liz Willoughby on wed 10 sep 03
Hello James,
I had a tenmoku glaze that seemed to always need constant stirring,
with settling in the bottom of very hard glaze, even with the
addition of bentonite. When the discussion came up last year about
using a capful of muriactic acid to the glaze, I decided to try it.
It worked beautifully, and a year later it is still working. The
glaze is nicely flocculated. I cannot say whether I have noticed a
difference in glaze application however, the glaze seems to go on as
usual. I usually dip, unless the piece requires spraying for an even
application of glaze, i.e. a large bowl.
Best regards. Liz
(am I remembering that you have a small tenmoku bowl of mine, from a
bowl benefit at NCECA?)
>
>interested in learning more on the subject of using muriatic
>acid in glazes to improve the evenness of the glaze coat on
>the bisqued ware. The way I understand it Tom uses muriatic
>acid to flocculate the glaze with the result that the glaze
>runs less on the pot thus achieving a more even coat of
>glaze. And while he mostly sprays his glazes on this will
>help those of use who dip apply our glazes. I have the
>following questions for discussion.
>
>Which glazes benefit from being flocculated? I read in the
>archive about frit containing glazes benefiting by not
>hardening in the bottom of the bucket, but my concern is
>more about even glaze application.
>
>In those instances where I must pour glazes on the bisque
>what difference will I likely see between the flocculated
>glaze coat and one not?
>
>Which flocculent to use with which glazes? (Calcium,
>feldspathic, etc.) Ivor mentioned the reaction between the
>acid and calcium based fluxes. Some glazes are somewhat
>naturally flocculated, but can they benefit from additional
>flocculation?
>
>When is it necessary to use a glaze suspending agent instead
>of flocculating the glaze? When to use both?
>
>In the interest of reducing iron content is it better to
>remove the glaze suspender bentonite from a glaze and
>substitute a flocculent? A different suspender? Both?
--
Liz Willoughby
RR #1
2903 Shelter Valley Rd.
Grafton, Ontario
Canada
K0K 2G0
905-349-3130
lizwill@phc.igs.net
James Bowen on wed 10 sep 03
I attended the Tom Coleman workshop last weekend and am now
interested in learning more on the subject of using muriatic
acid in glazes to improve the evenness of the glaze coat on
the bisqued ware. The way I understand it Tom uses muriatic
acid to flocculate the glaze with the result that the glaze
runs less on the pot thus achieving a more even coat of
glaze. And while he mostly sprays his glazes on this will
help those of use who dip apply our glazes. I have the
following questions for discussion.
Which glazes benefit from being flocculated? I read in the
archive about frit containing glazes benefiting by not
hardening in the bottom of the bucket, but my concern is
more about even glaze application.
In those instances where I must pour glazes on the bisque
what difference will I likely see between the flocculated
glaze coat and one not?
Which flocculent to use with which glazes? (Calcium,
feldspathic, etc.) Ivor mentioned the reaction between the
acid and calcium based fluxes. Some glazes are somewhat
naturally flocculated, but can they benefit from additional
flocculation?
When is it necessary to use a glaze suspending agent instead
of flocculating the glaze? When to use both?
In the interest of reducing iron content is it better to
remove the glaze suspender bentonite from a glaze and
substitute a flocculent? A different suspender? Both?
| |
|
