Steve McNutt on fri 5 may 00
Two questions:
First....
I am making Vince's terra sig for the first time and can only get sodium
silicate in solution. I have dry soda ash. So, how to I measure that to fit
the following formula:
.25% soda ash
.25% sodium silicate
I am planning to make two batches. One with 12# of ball clay and one with
16# of redart.
Second....
Where can I find a glaze hydrometer. I have called two suppliers I normally
use and they don't have them. Do I really need one? I should have made that
the first question. The answer is probably I will be glad I have it.
Anyway, we'll see what you all have to say on that.
Isn't this just great. I am not at all stressed by not knowing because I
know the answer is at my fingertips. I talked with a builder today about my
studio. Very nervous here...or maybe the feeling is excitement. I have
months to distinguish the difference.
Meanwhile, thanks for help on the above.
Mary Beth Bishop
Durham, NC
Cindy Strnad on sat 6 may 00
Mary,
I got my glaze hydrometer from Dakota Potters supply (dakotapotters@11.net )
(605-332-1946), but I'm sure most places could at least order you one. Be
sure to get a graduated cylinder to do your testing in. Very few vessels are
tall and narrow enough for this purpose.
As for the sodium silicate, I weighed it wet and that worked all right for
me. I've never seen it any way except in solution, so I just assumed that
was what was expected. Maybe I was wrong . . . anyway, it worked out okay
for me.
Have fun,
Cindy Strnad
earthenv@gwtc.net
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
Penny Hosler on sat 6 may 00
Mary Beth,
I'll be interested in the answer to the sodium silicate question.
Never seen it except in liquid form.
You can get a glaze hydrometer from Clay Art Center in Tacoma,
WA--cost about $15. This address will take you to the right page:
http://www.clayartcenter.com/equipglaze_test.htm
Penny in Sequim, WA
-----Original Message-----
From: Steve McNutt
To: CLAYART@LSV.UKY.EDU
Date: Friday, May 05, 2000 12:58 PM
Subject: Vince Pitelka -Terra Sig Questions
>----------------------------Original
message----------------------------
>Two questions:
>First....
>I am making Vince's terra sig for the first time and can only get
sodium
>silicate in solution. I have dry soda ash. So, how to I measure
that to fit
>the following formula:
>
>.25% soda ash
>.25% sodium silicate
>
>I am planning to make two batches. One with 12# of ball clay and one
with
>16# of redart.
>
>Second....
>Where can I find a glaze hydrometer. I have called two suppliers I
normally
>use and they don't have them. Do I really need one? I should have
made that
>the first question. The answer is probably I will be glad I have it.
>Anyway, we'll see what you all have to say on that.
>
>Isn't this just great. I am not at all stressed by not knowing
because I
>know the answer is at my fingertips. I talked with a builder today
about my
>studio. Very nervous here...or maybe the feeling is excitement. I
have
>months to distinguish the difference.
>Meanwhile, thanks for help on the above.
>
>Mary Beth Bishop
>Durham, NC
>
vince pitelka on sat 6 may 00
> ----------------------------Original message----------------------------
> Two questions:
> First....
> I am making Vince's terra sig for the first time and can only get sodium
> silicate in solution. I have dry soda ash. So, how to I measure that to
fit
> the following formula:
Just weigh it out and put it in. Be sure to dissolve the soda ash in hot
water.
Good luck
Vince
Vince Pitelka
Home - vpitelka@dekalb.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
http://www.craftcenter.tntech.edu/
Tom Buck on mon 8 may 00
MB:
1) You don't need a hydrometer; they are very inconsistent. To
check the density of the mixed glaze slurry simply weigh 200 mL (7 oz is
close), and divide the weight (commonly 300 - 320 grams) by 200, and there
you have it, 1.50 - 1.60 g/mL.
2) Sodium silicate is called waterglass and it usually is Liquid
unless it sits around for months. Assume that the liquid you bought is
close to the molecular formula, ie, weight, of Na2SiO3 and go accordingly,
ie, weigh out 0.25% of the liquid and add it to the TS water.
Good pots. 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
Martin Howard on mon 8 may 00
Some hydrometers use the odd Baume scale. I have managed to convert Baume to
Specific Gravity, which can then be used to convert to ounces per pint (UK
or US). The first and third columns are Baume figures with the 2nd and 4th
being the SG equivalent.
Baume SG Baume SG
38 1.36 0.00 1.00
39 1.37 2 1.01
40 1.38 4 1.03
41 1.39 6 1.04
42 1.41 8 1.06
43 1.42 10 1.07
44 1.44 12 1.09
45 1.45 14 1.11
46 1.46 16 1.12
47 1.48 18 1.14
48 1.49 20 1.16
49 1.51 22 1.18
50 1.53 24 1.20
51 1.54 26 1.22
52 1.56 28 1.24
53 1.58 30 1.26
54 1.59 32 1.28
55 1.61 34 1.31
56 1.63 36 1.33
57 1.65
58 1.67
59 1.69
60 1.71
61 1.73
62 1.75
Why do some pottery groups use Baume? Good question. No answer.
Martin Howard
Webb's Cottage Pottery
Woolpits Road, Great Saling
BRAINTREE, Essex CM7 5DZ
England
martin@webbscottage.co.uk
Lynne Berman on mon 8 may 00
Hydrometers are available from any auto supply store. And yes, you need one.
They cost between $2 and $3.
Lynne Berman, a grateful clayart student of Vince's
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