Kathy Maves on wed 30 jan 02
Hi,
One of Earl's recent posts mentioned volcanic ash as
an inconsistent ingredient. I've a new romance with
it, are we star-crossed lovers?
I've often heard the same argument about
wollanstonite vs. whiting and silicia. (Wollanstonite
being better, more consistent.) Still, I very rarely
see other potters in this area using wollanstonite. I
see alot of whiting, often as the main/only flux. The
price for woll. is higher, I suppose.
How common a problem is inconsistency from Volcanic
ash? Wollanstonite? Who broke your heart, and would
you do it again?
Afraid to buy my next bag of V.Ash,
kathy
kathymaves@yahoo.com
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Earl Brunner on thu 31 jan 02
It's not that bad, just buy enough of it to last you awhile, then you have a
consistent batch. I use it in a studio setting here I might not be working next
year, to me, it's important that the studio have good reliable glazes that can be
reproduced after I'm gone. Our main supplier of ceramic supplies locally shifted
from one company to another over the last two years and not knowing if materials
are coming from the same source has been a concern. To be honest, I really haven't
noticed any major problems.
Kathy Maves wrote:
> Hi,
> One of Earl's recent posts mentioned volcanic ash as
> an inconsistent ingredient. I've a new romance with
> it, are we star-crossed lovers?
> I've often heard the same argument about
> wollanstonite vs. whiting and silicia. (Wollanstonite
> being better, more consistent.) Still, I very rarely
> see other potters in this area using wollanstonite. I
> see alot of whiting, often as the main/only flux. The
> price for woll. is higher, I suppose.
> How common a problem is inconsistency from Volcanic
> ash? Wollanstonite? Who broke your heart, and would
> you do it again?
>
> Afraid to buy my next bag of V.Ash,
>
> kathy
> kathymaves@yahoo.com
>
> __________________________________________________
> Do You Yahoo!?
> Great stuff seeking new owners in Yahoo! Auctions!
> http://auctions.yahoo.com
>
> ______________________________________________________________________________
> 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.
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
Michael McDowell on thu 31 jan 02
Kathy Maves asks about the reliability of Volcanic Ash as a glaze ingredient.
I think you'll find that any raw material can be highly variable if you don't
take steps to make it otherwise. Every time we order new, there is the
possibility that the product will be more or less different than the last
time. The more you come to control your glazes, the more sensitive you'll be
to this. Best way around this is to stock in enough of each critical raw
material to last for a while, then be wary when you have to go back to the
store for more.
I have about five tons of ash from Mt. St. Helens 1980 eruption. This means
that for me, volcanic ash is the most stable of ingredients, because I'll
probably never have to go get it again. On the other hand, storage can be a
problem. I just moved the whole five tons from one spot to another here. It
gave me a lot of opportunity to reflect on the "wisdom" of stocking away so
much. It's a question that each of us has to resolve for ourselves. We are
never going to eliminate variability from all our sources. Some can be reduced
if you invest in a large stockpile of materials. But you will still face
variability someday. Prepare yourself with the ability to adapt through
knowledge of glaze chemistry and the willingness to constantly test and
experiment.
Michael McDowell
Whatcom County, WA USA
michael@mcdowellpottery.com
http://www.mcdowellpottery.com
Cindy Strnad on thu 31 jan 02
Dear Kathy,
Try to buy your next bag of volcanic ash from the
same supplier, and buy a lot of it. Volcanic ash
is less consistent than the famed Gerstly Borate.
The composition varies wildly from volcano to
volcano, and one seldom has access to information
about the point of origin. But don't despair.
Simply buy it in large enough quantities that
you'll never need to buy any more and you'll be
just fine. It's not that hard or that much, if you
do the math.
Best wishes,
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
cindy@earthen-vessels-pottery.com
http://www.earthen-vessels-pottery.com
Roger Korn on thu 31 jan 02
Two points: I have ash from Mt St. Helens, collected from Ritzville by Michael
McDowell. Ritzville is waaay downwind from St. Helens, so the fallout there was
quite uniform in size and composition. I also have ash I've collected from various
places, tested, and kept in separate bags. After the testing, I concluded that
there was not that much difference between the ash from the places where I
collected, so I mixed it all together, to create a uniform lifetime supply. Seems
to work just fine. If you buy ash from a ceramics supplier, do follow Cindy's
advice if you want a consistant ingredient. Chances are, the supplier won't have an
analysis available for each batch.
Roger
Cindy Strnad wrote:
> Dear Kathy,
>
> Try to buy your next bag of volcanic ash from the
> same supplier, and buy a lot of it. Volcanic ash
> is less consistent than the famed Gerstly Borate.
> The composition varies wildly from volcano to
> volcano, and one seldom has access to information
> about the point of origin. But don't despair.
> Simply buy it in large enough quantities that
> you'll never need to buy any more and you'll be
> just fine. It's not that hard or that much, if you
> do the math.
>
> Best wishes,
>
> Cindy Strnad
> Earthen Vessels Pottery
> RR 1, Box 51
> Custer, SD 57730
> USA
> cindy@earthen-vessels-pottery.com
> http://www.earthen-vessels-pottery.com
>
> ______________________________________________________________________________
> 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.
--
Roger Korn
McKay Creek Ceramics
In AZ: PO Box 463
4215 Culpepper Ranch Rd
Rimrock, AZ 86335
928-567-5699 <-
In OR: PO Box 436
31330 NW Pacific Ave.
North Plains, OR 97133
503-647-5464
iandol on thu 31 jan 02
Dear Kathy Maves=20
You say <wollanstonite. I see a lot of whiting, often as the main/only flux.>>
This potter uses Wollastonite. Thinks it's great stuff. Gets rid of =
several bugbears associated with the Whiting+Silica syndrome. But then, =
I invent my own glazes. Do the hard yards of weighing and mixing those =
thirty six samples. Use my own matrix of weighing values. Test them on =
my clays. Getting great results. It may take a couple of hours longer =
but it is rewarding. But then, it takes a few years to develop the =
philosophy needed to make the breakthrough to independence. Whiting, a =
Flux? I could say more but I will hold my tongue.
Best regards,
Ivor Lewis. Redhill, South Australia.
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