Greg Skwira on thu 13 apr 00
Is NC-4 soda feldspar an OK swap in a glaze recipe that calls for Kona F-4?
I've looked at the percentage analyses on the Ceramics Web (although the data
are some years old), and the components are the same and all within a percent
of each other. Looks good to me, but I'm new enough to be uncertain and would
appreciate a yea or nay from those more experienced. Thanks.
--Greg Skwira
Murray & Bacia Edelman on fri 14 apr 00
I have found little difference in the substitution of NC-4 for Kona F-4.
Our local
clay supply, Paoli Clay, only offers NC-4 for a soda spar. Since it saves
the hassle
of ordering and paying for shipping, and since the glazes I use seem
identical,
I don't worry about it.
Roy, will you corroborate?
Bacia
At 01:32 PM 04/13/2000 EDT, you wrote:
>----------------------------Original message----------------------------
>Is NC-4 soda feldspar an OK swap in a glaze recipe that calls for Kona F-4?
>I've looked at the percentage analyses on the Ceramics Web (although the data
>are some years old), and the components are the same and all within a percent
>of each other. Looks good to me, but I'm new enough to be uncertain and would
>appreciate a yea or nay from those more experienced. Thanks.
>
>--Greg Skwira
>
Ron Roy on sun 16 apr 00
My analysis are quite close - I would expect the C6 spar to flux a bit more
based on the analysis I have - they are old however. Will probably depend
on how much spar there is in the recipe - a wild guess would be - over 40%
and some differences might be apparent. Depends on how balanced the glaze
is.
The expansion is about the same for both.
RR
>----------------------------Original message----------------------------
>I have found little difference in the substitution of NC-4 for Kona F-4.
>Our local
>clay supply, Paoli Clay, only offers NC-4 for a soda spar. Since it saves
>the hassle
>of ordering and paying for shipping, and since the glazes I use seem
>identical,
>I don't worry about it.
>Roy, will you corroborate?
>Bacia
>
>
>At 01:32 PM 04/13/2000 EDT, you wrote:
>>----------------------------Original message----------------------------
>>Is NC-4 soda feldspar an OK swap in a glaze recipe that calls for Kona F-4?
>>I've looked at the percentage analyses on the Ceramics Web (although the data
>>are some years old), and the components are the same and all within a percent
>>of each other. Looks good to me, but I'm new enough to be uncertain and would
>>appreciate a yea or nay from those more experienced. Thanks.
>>
>>--Greg Skwira
>>
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
Greg Skwira on mon 17 apr 00
thanks for thge response. The question, in fact, is aimed at the recipe
you're helping me with. I've been using a bag of F-4, which is about gone;
bought a new bag the other day -- and saw it was NC-4 (which the supplier
said was interchangable.) I trust the supplier, and the ClayArt data seemed
to back him up, but it's good to have an expert opinion. Based on your
message, sounds like it should be fine in the recipe I'm currently testing:
F4 feldspar 14.5%
Whiting 6.5
Talc 2
F3134 27.5
EPK 21
Silica 28.5
Bentonite 2
102
plus opacifier: 2.75% tin oxide
By the way, the first test tiles and a couple of small pieces with this
recipe are in the kiln now. We'll get a look tomorrow. The thing is, the LAST
recipe looked great on test tiles and a few small pieces, too...and the
crazing only became apparent a week or so later (AFTER I had mixed up a
16k-gram batch, unfortunately.) So I guess I'll just have to go slow and to
things a step at a time. I'll keep your posted. Again, thanks.
--Greg Skwira
I
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