Brad Sondahl on sat 2 nov 02
My last set of tests involved substituting Frit 3134 for Frit P25 in my
crystalline base.
I was looking at the makeup of several frits, and it seems to me that
boron is the key ingredient for most frits today (being that leaded
frits are mostly not used by us common folk). Frit 3134 has twice the
percentage of boron that P25 has. Since they cost similarly ($1.60 /lb
in quantity), the thought was that I could use half as much frit and
achieve the same result. For the purpose of my test, the remnant
percentage was replaced with feldspar, since when firing at stoneware
temperatures, feldspar by itself melts well. (I realize that I'm
blithely ignoring Molecular Weights, but I'm more an intuitive
experimenter than a scientific one)
The test did work out reasonably well, so it seems to beg the
question--why not just always use the high boron frits, since the other
RO's and R2O's are cheaper and easily available? From the chart in
Minnesota Clay's catalog, these include
Ferro 3124 (B203-13.7%)
Ferro 3134 (B2O3-23.1%)
Pemco P25 (B2O3-12.1%)
Pemco P54 (B2O3-23.3%)
Fusion F79 (B2O3-27%)
Of these, the F79 is most expensive, with 3134 and P54 roughly the same.
I mention expense because frits are about 7 times more expensive than
feldspar, but often used similarly (in fairly high percentages in a
glaze). Among the ingredients I use, Zirconium opacifiers and Zinc are
the only high percentage ingredients similar in price.
I still have a good supply of P54, but think I may try a batch to see
how the other frit works out.
Anyone else do much with frit substitutions?
Brad Sondahl
--
For original art, music, pottery, and literature, visit my homepage
http://sondahl.com
Pottery sales page http://sondahl.freeyellow.com
My music site at mp3.com http://www.mp3.com/sondahl
Ilene Mahler on sun 3 nov 02
The gereral color 106 is one of the frits used to sub something no longer in
use p283 check General Color they have lotsa subs... Ilene in Conn
----- Original Message -----
From: Brad Sondahl
To:
Sent: Sunday, November 03, 2002 1:22 AM
Subject: Thinking about frits
> My last set of tests involved substituting Frit 3134 for Frit P25 in my
> crystalline base.
> I was looking at the makeup of several frits, and it seems to me that
> boron is the key ingredient for most frits today (being that leaded
> frits are mostly not used by us common folk). Frit 3134 has twice the
> percentage of boron that P25 has. Since they cost similarly ($1.60 /lb
> in quantity), the thought was that I could use half as much frit and
> achieve the same result. For the purpose of my test, the remnant
> percentage was replaced with feldspar, since when firing at stoneware
> temperatures, feldspar by itself melts well. (I realize that I'm
> blithely ignoring Molecular Weights, but I'm more an intuitive
> experimenter than a scientific one)
> The test did work out reasonably well, so it seems to beg the
> question--why not just always use the high boron frits, since the other
> RO's and R2O's are cheaper and easily available? From the chart in
> Minnesota Clay's catalog, these include
> Ferro 3124 (B203-13.7%)
> Ferro 3134 (B2O3-23.1%)
> Pemco P25 (B2O3-12.1%)
> Pemco P54 (B2O3-23.3%)
> Fusion F79 (B2O3-27%)
> Of these, the F79 is most expensive, with 3134 and P54 roughly the same.
>
> I mention expense because frits are about 7 times more expensive than
> feldspar, but often used similarly (in fairly high percentages in a
> glaze). Among the ingredients I use, Zirconium opacifiers and Zinc are
> the only high percentage ingredients similar in price.
> I still have a good supply of P54, but think I may try a batch to see
> how the other frit works out.
> Anyone else do much with frit substitutions?
> Brad Sondahl
> --
> For original art, music, pottery, and literature, visit my homepage
> http://sondahl.com
> Pottery sales page http://sondahl.freeyellow.com
> My music site at mp3.com http://www.mp3.com/sondahl
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
>
June Perry on sun 3 nov 02
Brad,
I've been doing a lot of reformulating of glazes for myself and others in
order to replace gerstley with frits. The three I use the most are Frits
3134, 3195 and 3124. If I have plenty of alumina in the glaze, I select all
or part of 3195 which has higher alumina, but still has a goodly amount of
boron. It would not be a good choice for a crystalline base but it works for
others.
I don't use frits as a substitute for gerstley, but instead, I bring the
gerstley containing glaze down to the molecular formula and then use glaze
software to match the glaze exactly, or as close as possible. The only
difference is that although I can get the KNA as a total the same, the amt
of K and the amt of Na usually don't match precisely particularly if you are
adjusting a glaze with a high level of potash feldsapr, because the frits
have so much Na in them. Only the 3124 has any K.
There are non boron frits as well as some like Ferro 3110 that has only a
small (.097moles) amount of boron.
When using the frits you're usually getting a lot of other materials in there
that gerstley or colemanite may not have, or not have in those proportions. I
find it best to use the software and match the molecular formula as closely
as possible.
I wish I had time to test all these revisions; but not at the moment!
Regards,
June Perry
http://www.angelfire.com/art2/shambhalapottery/index.html
Ron Roy on sun 3 nov 02
Hi Brad,
You are right - you are buying the frit for the boron - so the more boron
the cheaper it is. You just have to choose the right frit so you don't get
what you don't want.
The absolutely best way is to use calculation - either by hand but software
would be best. That way you can duplicate the glaze almost exactly taking
into account that if you use less frit you will get less melting.
I can demo this if you send me the recipe.
RR
>My last set of tests involved substituting Frit 3134 for Frit P25 in my
>crystalline base.
>I was looking at the makeup of several frits, and it seems to me that
>boron is the key ingredient for most frits today (being that leaded
>frits are mostly not used by us common folk). Frit 3134 has twice the
>percentage of boron that P25 has. Since they cost similarly ($1.60 /lb
>in quantity), the thought was that I could use half as much frit and
>achieve the same result. For the purpose of my test, the remnant
>percentage was replaced with feldspar, since when firing at stoneware
>temperatures, feldspar by itself melts well. (I realize that I'm
>blithely ignoring Molecular Weights, but I'm more an intuitive
>experimenter than a scientific one)
>The test did work out reasonably well, so it seems to beg the
>question--why not just always use the high boron frits, since the other
>RO's and R2O's are cheaper and easily available? From the chart in
>Minnesota Clay's catalog, these include
>Ferro 3124 (B203-13.7%)
>Ferro 3134 (B2O3-23.1%)
>Pemco P25 (B2O3-12.1%)
>Pemco P54 (B2O3-23.3%)
>Fusion F79 (B2O3-27%)
>Of these, the F79 is most expensive, with 3134 and P54 roughly the same.
>
>I mention expense because frits are about 7 times more expensive than
>feldspar, but often used similarly (in fairly high percentages in a
>glaze). Among the ingredients I use, Zirconium opacifiers and Zinc are
>the only high percentage ingredients similar in price.
>I still have a good supply of P54, but think I may try a batch to see
>how the other frit works out.
>Anyone else do much with frit substitutions?
>Brad Sondahl
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
| |
|
