Don Curtis on tue 24 feb 98
I have a Raku glaze from "The Potters Palette" which calls for a high alkali
frit.
High alkali frti 85
Ball Clay 7.5
Whiting 7.5
We have the following four frits in our studio-Ferro Frit 3110,3124,3134,3195.
Would one of these be better to use or should we order another frit. Thanks in
advance
Don
In beautiful Western Massachusetts
John Post on wed 25 feb 98
At 08:00 AM 2/24/98 EST, you wrote:
>----------------------------Original message----------------------------
>I have a Raku glaze from "The Potters Palette" which calls for a high alkali
>frit.
>
>High alkali frti 85
>Ball Clay 7.5
>Whiting 7.5
>
>We have the following four frits in our studio-Ferro Frit
3110,3124,3134,3195.
>Would one of these be better to use or should we order another frit.
Thanks in
>advance
>
>Don
>In beautiful Western Massachusetts
>
Hi Don,
Use the 3110. It's good in recipes that call for a soda frit or a high
alkali frit.
Frit 3110
---------
Type: frit
Formula: % 15.30 Na2O 2.30 K2O 6.30 CaO 2.60 B2O3 3.70 Al2O3
69.80 SiO2
Molecular Wt.: 100.0
Frit 3110 supplies SiO2, Al2O3, and a variety of fluxes,
especially Na2O. The high Na2O is what makes this a high alkali frit.
Notes:
A soda frit. High alkali frit.
John Post
jp6mchp@moa.net
Sterling Heights, Michigan
Gavin Stairs on wed 25 feb 98
....
>We have the following four frits in our studio-Ferro Frit
3110,3124,3134,3195.
>Would one of these be better to use or should we order another frit.
3110 is about 17% KNaO. That's quite a lot. The others are more B2O3.
Alkali refers primarily to the Group I elements (Li, K, Na, Rb, Cs...), and
secondarily to the alkali earths, Group II (Be, Mg, Ca, Sr, Ba...). Of
these, the important ones from a potting perspective are Lithium (Li),
Potassium(K), Sodium (Na) and Magnesium (Mg), Calcium (Ca). These are all
strong fluxes, because they are all strongly polar, and therefore disrupt
the largely covalent glass matrix, making it melt at a lower than normal
temperature.
So 3110 is probably what your recipe was calling for, but that will make a
glaze with high expansion. One that will craze easily, and melt easily,
too. This frit is not far from bottle glass. In fact, the whole glaze is
not far from bottle glass. Be prepared for runs and drips and crazes.
Maybe that's what you want. This is a decorative glaze, not a liner glaze.
Maybe you should just take a pepsi bottle, crush it up, suspend it in a
little bentonite and ball clay, and get almost the same effect. If you
have a hammer mill or a ball mill, you can save yourself some money.
Gavin
George Mackie on wed 25 feb 98
Don - Frit 3110 has the highest percentage of Na plus K and would be the
one to use. george
paul wilmoth on wed 25 feb 98
Don,
For Raku that I imagine that you want to craze use 3110. This frit has a
higher amount of soda than the rest and less alumina, it would be good
for raku. The other frits are better for functional glazes.
good luck - Paul
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