mel jacobson on sat 15 sep 07
this is observation, not molecular science.
i went through about 30 pieces of home use
ware that we have used for in some cases 40 years...with
rhodes 32.
meat servers, big food bowls that have been used hundreds
of times.
they look like they just came from the kiln.
not a mark on them. bowls that sharlene uses for her
breakfast cereal every day....they are like kiln new.
there are no craze lines full of black stuff.
however, a set of dishes that i use, made from temmoku
has cut marks all over them. they have not held up as well
as the rhodes 32.
i have always added additional silica and titanium to my rhodes32.
it takes the flat surface off the piece...and gives it more of a
semi/butter/gloss surface.
i found this glaze years ago, and many of my every day customers
love it and buy it. if i was starting all over again, i might change
my `signature` glaze. but, folks beg for it. buy it all the time.
love it best. so, should i throw it out? i don't think so.
i have made thousands of pots with new and exciting glazes.
i experiment all the time. but, none of it sells like my oatmeal
rhodes 32 with aqua and dark brown patterns.
just the way it is.
it is a glaze that was developed my david shaner to take
advantage of high iron clay bodies...and that is what i have
used for 40 years...it fits me well.
mel
from: mel/minnetonka.mn.usa
website: http://www.visi.com/~melpots/
Clayart page link: http://www.visi.com/~melpots/clayart.html
Ron Roy on tue 18 sep 07
Hi David,
I just had a look at my dinnerware glazed with my Tenmoku and it seems to
have lasted quite well - it's used about once a month - sometimes more -
and goes into the dishwasher - it seems fine after at least 30 years of
use.
Would you send me the recipe you use - perhaps there is a clue in the
molecular formula.
RR
>Through the years I have found that looking at the molecular
>formula for a glaze is often not a good indication of how
>durable it will hold up in the long term.
>The tenmoku glaze that I have used for many years (Seacrest
>tenmoku) shows wear after years of use - dulling of the surface.
>If you look at the formula, it is well within the parameters of a
>durable cone 10 glaze.
>I have a matt Shaner's orange bowl with, according to limit formulas,
>low silica, but is still in like-new condition after 25 years of use.
>
>Perhaps matt glazes don't show wear as much because the
>surface started out matt. Glossy glazes will show wear more
>because the wear turns the surface matt.
>
>David Hendley
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Ron Roy on wed 19 sep 07
Hi David,
I calculated yours without the zinc which puts them closer together but
mine still has more alumina and silica.
Perhaps the large amount of iron plays a role in this. I'm a little
surprised counting that mine has more alkali flux which is supposed to
soften a glaze.
Here is mine in case you want to make further comparisons.
RR Tem Org tot 100.RCP
-------------------
G 200 SPAR.......... 59.00
WHITING............. 12.50
BELL DARK........... 7.00
SILICA.............. 21.50
RED IRON OX......... 7.70
----------
107.70
FORMULA & ANALYSIS
------------------
*BaO........
*CaO........ .58
*MgO........ .00
*K2O........ .29
*Na2O....... .13
Fe2O3...... .21
TIO2....... .01
AL2O3...... .55
SiO2....... 4.74
P2O5.......
RATIO 8.61
EXPAN 567.04
WEIGHT 443.11
>----- Original Message -----
>> Hi David,
>>
>> I just had a look at my dinnerware glazed with my Tenmoku and it seems to
>> have lasted quite well - it's used about once a month - sometimes more -
>> and goes into the dishwasher - it seems fine after at least 30 years of
>> use.
>>
>> Would you send me the recipe you use - perhaps there is a clue in the
>> molecular formula.
>>
>> RR
>
>
>
>Seacrest Tenmoku, circa 1975 - cone 10
>Custer spar...54
>whiting...13
>barium carb...2.5
>zinc ox...2.5
>EPK...6
>silica...22.5
>red iron ox...6
>total...106.5
>
>With Al2O3 of .44 and SiO over 4.00, this should be a very durable glaze.
>
>David Hendley
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
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