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low fire salt

updated sun 20 may 07

 

SJGMIC@aol.com on fri 23 aug 96

I am contemplating using my raku kiln for low fire salt and would like to
find out if anyone has done this and what effects it has on the multi-use of
the kiln. Any information would be appreciated on the process, etc..

Phil Rogers on fri 18 may 07


In Phil Rogers's book on salt glazing, he says "Potter such as Paul =
Soldner
in the USA and David Miller in France have incorporated salt into the =
raku
process by coating a fairly standard raku-type claybody with slips that
contain a low-temperature alkaline frit, often in conjunction with =
copper
oxide (present in the slip or the salt). This can result in spectacular
flashed pinks and reds."=20

Many years ago I played around with this technique during our annual
workshops here at the pottery. It worked very well in a small wood fired
raku kiln which was tumbled stacked with pots along with packets of salt
mixed with copper carbonate. The slip recipe I no longer have but I took =
my
initial recipe from David Miller via an article in a Ceramic Review =
Circa
1985 0r thereabouts. The slip did indeed contain alkaline frit. The =
colours
were often dramatic. Pinks and blushes of Peach with yellows. However, =
the
one problem I never did solve was the fugitive nature of the surface. =
The
colours disappeared over a period of time and, due to the porous nature =
of
the fired clay and the hydroscopic nature of salt, the pots left a damp
patch on any surface upon which they were placed for ever! My feeling is
that we were firing them too low at 950 degrees C. maybe a slightly =
higher
temperature, perhaps around 1060 degrees C might have solved these =
issues.
David Miller certainly seemed to have perfected the technique as he sold
many such pots at that time. As I said, we were playing with it for the
benefit of workshop attendees and it never really was a central interest =
for
me - just a bit of fun.

=20

Phil Rogers

Bonnie Staffel on sat 19 may 07


Phil, I don't know if this material would solve the problem of the =
colors
fading on you in this low fire technique, but I use a product called
WeldBond thinned down to a skimmed milk consistency and paint it on the =
pot.
It is not shiny. This product is used in cementing outdoor products,
including cement blocks, etc. I have found that my pit fired pots are
keeping their color as well as my smoke fired pots with my new smoke =
color.
It also makes the pot waterproof, however, since salt is involved, this
would have to be tested. I have filled a vase with water for flowers =
and
placed it on the proverbial paper towel with no hint of dampness.

This product is made in Canada and can be found on the Internet. I
purchased mine locally but may be just a little hard to find.

Bonnie Staffel

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