David Malicky on fri 8 sep 00
i've been experimenting with this glaze too, though my problems have been
pinholing.
here's the recipe i started with:
epk 23.5
3134 39.2
custer 23.5
silica 13.8
+ rutile 4
+ cobalt ox 2
i fire in a skutt elec. to cone 6, using the 'slow' fire mode.
my experience...
upon application: it can be hard to smooth over the 'bubble' holes due to the
high epk. also cracks where thick (veegum helps).
after normal firing: fairly runny, pinholes especially where thick, goes green
where thin (rims), goes whitish where thick (2 dips). very nice rutile pattern
at medium thickness (single dip). a 2nd firing is even nicer, though runnier of
course.
after a normal firing + slow cool-down: much lighter blue, not very nice.
food safe?: i read a post recently that it leaches cobalt, but not sure if it
was significant.
i tried some variations (added more custer - no effect, then talc, dolomite, and
more iron).
+ 5 dolomite with 1 dip fixes the pinholes, and results in a brighter blue -
some may find it too bright - almost barium-like.
+ 2.5 dolomite, 2.5 talc, 1.0 RIO also fixes the pinholes, and tones down the
blue to almost a navy, but with some interested white speckles in it.
presumably 0.5 RIO would brighten up the blue if desired.
dave malicky
ps. some pics of my work (cone 10, raku) at new web site below:
----------------------------------------------------------
David Malicky
Mechanical Engineering Department
Valparaiso University
David.Malicky@valpo.edu
http://diamond.gem.valpo.edu/~dmalicky/life/life.html
219-464-5062
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