Dave Finkelnburg on sun 28 nov 99
All,
On Wednesday I wrote, "....3134 contains less than half as much
boron/pound as Gerstley borate..." That's not correct. In an e-mail this
evening Tom Buck reminded me of a current analysis for Gerstley borate he
sent the list last May. It showed 26% B2O3 in Gerstley borate. Ferro frit
3134 has 23% B2O3. I sincerely apologize for my error. My thanks to Tom
for pointing out the correct information.
Dave Finkelnburg
Tom Buck on mon 29 nov 99
Ah me!
Ron: I didn't say what Dave F says I did; all I did was cite the
GB analsyes you and I have collected over time. DF made his jump and rang
me in on it. Of course, I know the diff between 3134 and GB.
BTW, here is what I sent to DF, a copy of a post to a Czech in
Prague, who earlier wanted to know how to fix a colemanite glaze recipe
using GB (or a substitute, say 3134) in place of C:
___________
J-M:
Here are the analyses you wanted:
Nepheline Syenite Canada (weight percent)
60.7 SiO2; 23.3 Al2O3; 0.07 Fe2O3; 4.6 K2O; 9.8 Na2O;
0.7 CaO; 0.1 MgO; 0.7 LOI.
Gerstley borate is complex... the grade has been
shifting steadily, and all I can do is give you the 1993,
1997, and 1999 levels in weight percent:
Gerstley Borate, as cited by Hamill & Gillespie:
as of 1993: 9.8 SiO2; 1.3 Al2O3; 0.35 Fe2O3; 0.14 K2O;
4.7 Na2O; 17.9 CaO; 3.5 MgO; 23.3 B2O3; 34.0 LOI.
as of Aug 97: 11.73 SiO2; 1.63 Al2O3; 0.48 Fe2O3; 1.38 K2O;
4.39 Na2O; 19.06 CaO; 4.10 MgO; 27.68 B2O3; 29.35 LOI,
as of May 1999: 21.2 SiO2; 7.0 Al2O3; 2.9 Na2O; 18.9 CaO;
25.7 B2O3; 22.5 LOI.
As you will see, you have to know when the glaze recipe first
was designed to know how to sub for the GB. Today's GB is
much more refractory than before.
Good tests. BFN. Tom.
-----------
Perhaps Dave F will explain his interpretation of this data to equate me
with a statement about how 3134 and GB inter-relate.
BFN. Peace. 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
Ron Roy on tue 30 nov 99
Thanks for telling me Tom - as you know we all have lapses now and then -
par for the course I think - but this one was puzzeling.
RR
>----------------------------Original message----------------------------
>Ah me!
> Ron: I didn't say what Dave F says I did; all I did was cite the
>GB analsyes you and I have collected over time. DF made his jump and rang
>me in on it. Of course, I know the diff between 3134 and GB.
> BTW, here is what I sent to DF, a copy of a post to a Czech in
>Prague, who earlier wanted to know how to fix a colemanite glaze recipe
>using GB (or a substitute, say 3134) in place of C:
>___________
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
Dave Finkelnburg on tue 30 nov 99
Tom,
I used to think Gerstley Borate had a lot of boron in it, about 52%
B2O3. The analyses you cite, and ones I have found elsewhere certainly
opened my eyes. Depending on which analysis I rely on, it's really got only
26 to 30% B2O3.
Ron is absolutely correct, that's a lot more boron than is in Ferro frit
3134. One certainly can't replace Gerstley borate directly, one for one,
with 3134. The frit doesn't have enough boron to permit that. I sure
apologize if anyone got the impression from what I wrote that one could.
Dave Finkelnburg
dfinkeln@cyberhighway.net
-----Original Message-----
From: Tom Buck
To: CLAYART@LSV.UKY.EDU
Date: Monday, November 29, 1999 1:24 PM
Subject: Re: CORRECTION: Re: Frits
----------------------------Original message----------------------------
Ah me!
Ron: I didn't say what Dave F says I did; all I did was cite the
GB analsyes you and I have collected over time. DF made his jump and rang
me in on it. Of course, I know the diff between 3134 and GB.
BTW, here is what I sent to DF, a copy of a post to a Czech in
Prague, who earlier wanted to know how to fix a colemanite glaze recipe
using GB (or a substitute, say 3134) in place of C:
___________
J-M:
Here are the analyses you wanted:
Nepheline Syenite Canada (weight percent)
60.7 SiO2; 23.3 Al2O3; 0.07 Fe2O3; 4.6 K2O; 9.8 Na2O;
0.7 CaO; 0.1 MgO; 0.7 LOI.
Gerstley borate is complex... the grade has been
shifting steadily, and all I can do is give you the 1993,
1997, and 1999 levels in weight percent:
Gerstley Borate, as cited by Hamill & Gillespie:
as of 1993: 9.8 SiO2; 1.3 Al2O3; 0.35 Fe2O3; 0.14 K2O;
4.7 Na2O; 17.9 CaO; 3.5 MgO; 23.3 B2O3; 34.0 LOI.
as of Aug 97: 11.73 SiO2; 1.63 Al2O3; 0.48 Fe2O3; 1.38 K2O;
4.39 Na2O; 19.06 CaO; 4.10 MgO; 27.68 B2O3; 29.35 LOI,
as of May 1999: 21.2 SiO2; 7.0 Al2O3; 2.9 Na2O; 18.9 CaO;
25.7 B2O3; 22.5 LOI.
As you will see, you have to know when the glaze recipe first
was designed to know how to sub for the GB. Today's GB is
much more refractory than before.
Good tests. BFN. Tom.
-----------
Perhaps Dave F will explain his interpretation of this data to equate me
with a statement about how 3134 and GB inter-relate.
BFN. Peace. 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
Khaimraj Seepersad on wed 1 dec 99
Dave ,
the early analysis of Gerstley Borate was much richer in Boric Oxide ,
That was why I sent the names of two frits , that fit your category .
I use an Artificial Gerstley Borate [ see Parmelee , frits ] and this
contains 50 to 47 % Boric Oxide .
When you use this A.G.Borate on 70 % NC4 feldspar , you will get a
glaze at 960 to 980 deg.C [ cone 09 to 08 ] , usually opaque to
translucent [ I am too lazy to try for clear ] It is my low - fire
feldspathic
glaze .
The boric oxide to silica is well balanced - 1 B203 to 3.5 SiO2 ,
plus about 13.5+ % Al203 .Probably to high in Al203 and Alkalines .
I have sat the glaze in vinegar and after a week , is unaffected .
When I get someone to ferry it , it is off to Alfred's . Mind you ,
Boric Oxide is the only toxic material .
It is a basic , Al203 , Si02 , Na20 , K20 , Mg0 , Ca0 + B203 glass .
I use a high expansion body , so the fit is good .
Try the frits , and let Ron [ ? ] recalculate on their chemical breakdown.
Khaimraj Seepersad
-----Original Message-----
From: Dave Finkelnburg
To: CLAYART@LSV.UKY.EDU
Date: 30 November 1999 7:51
Subject: Re: CORRECTION: Re: Frits
>----------------------------Original message----------------------------
>Tom,
> I used to think Gerstley Borate had a lot of boron in it, about 52%
>B2O3. The analyses you cite, and ones I have found elsewhere certainly
>opened my eyes. Depending on which analysis I rely on, it's really got
only
>26 to 30% B2O3.
> Ron is absolutely correct, that's a lot more boron than is in Ferro
frit
>3134. One certainly can't replace Gerstley borate directly, one for one,
>with 3134. The frit doesn't have enough boron to permit that. I sure
>apologize if anyone got the impression from what I wrote that one could.
> Dave Finkelnburg
> dfinkeln@cyberhighway.net
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