Darcy on tue 15 apr 97
Four years ago I purchased a bag of volcanic ash from Marjon in Tucson,
Arizona called "Navajo Processed Pumice" which was made by American Pumice
Co., Santa Fe, New Mexico. I've been unable to obtain the same effects
with the volcanic ash I've obtained on the east coast. I called
information in Santa Fe but they had no listing for this company. Does
anybody know if American Pumice Co. still exists and if their pumice is
available on the east coast?
Randy O'Brien
Ithaca, NY
dln8@cornell.edu
Darrol F. Shillingburg on wed 16 apr 97
Hi Randy,
The number for Santa Fe Clay is:505/ 984-1122. The may have the material you
seek. Also Ceramic King in Albuquerque list a Volcanic Ash(New Mexico) in their
catalogue for $.80/lb. Their number is 505/881-2350.
Good luck,
Darrol in Elephant Butte, NM
Bette Lee Jablow on mon 23 feb 98
Greetings from a newcomer to pottery and clayart. I have learned so much from
you all. Thanks for being there.
I have been given a "hand-me-up" from my son of Mt. St. Helens ash. It was
harvested during a visit to Mt. Ranier by scraping it off the snow shortly
after the eruption. (A great trip by the way - the Pacific Northwest was
almost empty of tourists that June. We had our pick of campgrounds and
campsites.)
I would love to experiment with it in glazes but have no idea where to start.
Processing, cleaning, percentages, what types of glazes etc. I have an
electric kiln and fire to cone 6 mostly but occasionally to cone 10. I use
mostly commercial glazes from Laguna but have made some from recipes. Any
suggestions greatly appreciated.
Bette Lee in Redding, CA (BJablow@aol.com) where we have almost finished
building the ark.
Paul Lewing on wed 25 feb 98
Bette,
Mt. St. Helens Ash is a very nice glaze material for both cone 10 and
cone 6. You can use it alone at c10, and it will make a dark brown
speckled gloss glaze, although you'll have to add some clay to it to
keep it in suspension. This stuff settles out FAST and HARD! Mix
about 3% bentonite with it dry. Weigh the two materials out, seal it
in a container, and shake it up well, then add water.
At c6, you'll need to flux it with something, as well as adding clay.
I've gotten a very nice speckled grey using 70% ash, 20% frit
(different frits produce different surfaces and colors), 5% EPK, and
5% bone ash to emphasize the specks. The specks will vary in size and
color, unlike the specks produced by ilmenite. You can then color the
glaze with oxides, and if the grey background limits you too much,
throw in some opacifier, either tin oxide or a zirconium opacifier.
To prepare the ash, dry it, and strain it through an 80-mesh screen,
mostly to get any rocks or organic material out of it. It should all
go through, although particle size as well as chemical composition
will vary. The closer to the mountain it was collected, the coarser
it will be.
You can also add it to any other glaze, maybe up to 25%. It will
often really liven up a flat colored glaze. Have fun with this stuff-
it's great, and CHEAP!
Paul Lewing, Seattle
Kollin Baker on wed 25 feb 98
I found in I think last Feb in Clay Art Mag. an article about Volcanic
ash.....^5-6
EASY :
^60% V. Ash
40% G. Borate
Ive added opacifiers with some success but just the straight 60/40 which
can be mesured in cups easily with 6-10% mason stains is an easy glazy.
Careful there are tendencys for the glaze to crawl on certain clay bodies
and sometimnes fall right off the pot but its so easy that its worth a try.
Kollin Baker
Pi Pottery and Design
Don Prey on thu 26 feb 98
Bette,
A source of information that will address all your questions is an article in
the January, 1981 issue of Ceramics Monthly. There is also a followup letter
in the March 81 issue.
Don Prey in Oregon
Don Jung on fri 27 feb 98
Paul...
Hmmm, you say CHEAP. Where do you get it from? Our supplier labels it
as pumice and it costs almost as much as a frit. I agree it's great
stuff, but is there a source, other than hiking up Mt St. Helen's,
that's actually 'cheap'?
thx
--
Don Jung
in rainy, windy, sunny, hailing, foggy Vancouver
email: don.jung@mail.icbc.com
Barb Lund on wed 12 jan 00
Could some kind person tell me a good supplier for volcanic ash? I have
this great overglaze recipe I'd like to try that calls for it. TIA Barb
from Bloomington
Barb Lund
barblund@bluemarble.net
520 West 6th St.
Bloomington, In 47404
USA
812-339-8476
Nina Jones on thu 13 jan 00
------------------
Hi, Barb. Great Lakes Clay in Carpentersville, IL has volcanic ash. Their
number is 800/258-8796.
=3E=3E=3E Barb Lund =3Cbarblund=40bluemarble.net=3E 01/12/00 04:34PM =
=3E=3E=3E
----------------------------Original message----------------------------
Could some kind person tell me a good supplier for volcanic ash? I have
this great overglaze recipe I'd like to try that calls for it. TIA Barb
from Bloomington
Barb Lund
barblund=40bluemarble.net
520 West 6th St.
Bloomington, In 47404
USA
812-339-8476
Earl Brunner on thu 13 jan 00
Volcanic ash also goes by the name Pumice from some suppliers. Since it can
very in composition form source to source, I would recommend getting a large
enough batch to have some consistency for awhile.
Barb Lund wrote:
> ----------------------------Original message----------------------------
> Could some kind person tell me a good supplier for volcanic ash? I have
> this great overglaze recipe I'd like to try that calls for it. TIA Barb
> from Bloomington
> Barb Lund
> barblund@bluemarble.net
> 520 West 6th St.
> Bloomington, In 47404
> USA
> 812-339-8476
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
Cindy Strnad on fri 14 jan 00
Barb,
Almost all the ceramic suppliers I have catalogs from list volcanic ash (or
pumice). The trick is, that volcanic ash will vary greatly depending upon
the source. You'll have to figure out for yourself what to do about. I
believe I heard that Seattle pottery carries Mt. St. Helens ash (big
surprise), but most of the ash I've seen listed isn't specifically
identified. In other words, it may take a bit of testing.
Cindy Strnad
Earthen Vessels Pottery
Custer, SD
Susan Kosko on fri 14 jan 00
I called Seattle Pottery this week about the Mt. St. Helens ash - alas, they
have no more. They know of nobody who sells any, and said the only way to get
it now is from someone's back yard. Is there anyone out there who wants to
sell some??? I've been using it over shino and a few other glazes, and it's
awesome. We have a margarine-tub of it, but at the rate I'm using it, I'll
need more!
Susan Kosko
New Durham, NH - the wind is howling, creating crashing waves on the south
shore of our lake (luckily we're on the north shore)
Cindy Strnad wrote:
> ----------------------------Original message----------------------------
> Barb,
>
> Almost all the ceramic suppliers I have catalogs from list volcanic ash (or
> pumice). The trick is, that volcanic ash will vary greatly depending upon
> the source. You'll have to figure out for yourself what to do about. I
> believe I heard that Seattle pottery carries Mt. St. Helens ash (big
> surprise), but most of the ash I've seen listed isn't specifically
> identified. In other words, it may take a bit of testing.
>
> Cindy Strnad
> Earthen Vessels Pottery
> Custer, SD
Jim Brooks on sat 15 jan 00
Barb.. i think Mt St Helens would be a good source................No..just
kidding.!!!. I have seen some ads in the CM for west coast clay /supplies
places that listed the ash.. It seems there was one in Portland Or. Check
some old CM and try to call one of them.. If they don't have it..im sure that
they would refer you to someone that can supply it..
Veena Raghavan on sat 15 jan 00
Message text written by Ceramic Arts Discussion List
>I called Seattle Pottery this week about the Mt. St. Helens ash - alas,
they
have no more. <
May I add a request to Susan Kosko's. If anyone has Mt. St. Helen's ash
they would like to sell, or know of a source where it is available, I would
love to get some. I have used pummice, but would like to try the Mt. St.
Helen's.
Thanks in advance.
Veena
Veena Raghavan
75124.2520@compuserve.com
Jeanne Wood on mon 17 jan 00
Hi Susan,
This is just a thought but may be a solution.
Many people who were affected by Mt. St. Helens ash
fall in 1980 gathered up buckets full to save for
posterity. Then began to consider a clean garage more
important and looked for someone to give the ash to. I
am still offered a bucket or jar of ash every few
years.
Possibly placing a classified ad requesting ash in
newspapers of cities that were once covered with ash
would yield some.
There may be people so interested in getting rid of it
you would only have to pay shipping, or even trade
them a pot.
Central Washington cities like Yakima, Richland,
Northeast Oregon towns, some Northern Idaho towns
might be places to try.
-Jeanne W.
--- Susan Kosko wrote:
> ----------------------------Original
> message----------------------------
> I called Seattle Pottery this week about the Mt. St.
> Helens ash - alas, they
> have no more. They know of nobody who sells any,
> and said the only way to get
> it now is from someone's back yard. Is there anyone
> out there who wants to
> sell some??? I've been using it over shino and a
> few other glazes, and it's
> awesome. We have a margarine-tub of it, but at the
> rate I'm using it, I'll
> need more!
>
> Susan Kosko
> New Durham, NH - the wind is howling, creating
> crashing waves on the south
> shore of our lake (luckily we're on the north shore)
>
> Cindy Strnad wrote:
>
> > ----------------------------Original
> message----------------------------
> > Barb,
> >
> > Almost all the ceramic suppliers I have catalogs
> from list volcanic ash (or
> > pumice). The trick is, that volcanic ash will vary
> greatly depending upon
> > the source. You'll have to figure out for yourself
> what to do about. I
> > believe I heard that Seattle pottery carries Mt.
> St. Helens ash (big
> > surprise), but most of the ash I've seen listed
> isn't specifically
> > identified. In other words, it may take a bit of
> testing.
> >
> > Cindy Strnad
> > Earthen Vessels Pottery
> > Custer, SD
>
__________________________________________________
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
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Paul Lewing on mon 17 jan 00
Veena Raghavan wrote:
If anyone has Mt. St. Helens ash
> they would like to sell, or know of a source where it is available, I would
> love to get some. I have used pummice, but would like to try the Mt. St.
> Helens.
Veena,
Mt. St. Helens Ash is quite different from what is usually sold by
ceramic supply houses as volcanic ash or pumice. That's usually from
the Midwest somewhere, having been blown out of that giant caldera in
northern New Mexico, if it's American. If it's from Europe, it's
usually from Mt. Etna.
What you need to do is take a road trip to eastern Washington, go to
some small town like Ritzville, find a large old parking lot somewhere
where they don't care much what the place looks like, and find the berm
of dirt along the back somewhere. That'll be where they bulldozed the
ash off in 1980, and it will still be there, free for the asking.
You might also try calling Clay Art Center in Tacoma, WA or Georgie's
Clay Supply in Portland, OR. They might have some. A lot of potters
hereabouts have a bucket of the stuff, but I don't know anybody who has
enough to sell. Sorry, but I'm keeping mine. I love the stuff.
Pal Lewing, Seattle
Jean Lutz on sun 25 jun 00
I just acquired a small bit of ash from Mt. St. Helens.
I fire electric, cone 6 oxy. I use Laguna's commercial glazes and have a
small sampling of Georgies specialty glazes.
Does anyone have any suggestions on how to use the ash with these glazes in
this firing enviornment? My only experience with ash was in a school
setting where it was fired to cone 10 gas reduction.
Jean Lutz
Scottsdale, AZ
Wade Blocker on mon 26 jun 00
Jean,
I would choose a mat or semi mat white glaze from your Laguna selection of
glazes and add increments of 10% to 40% of ash to see what it does for your
glaze. The 10% might just alter the glaze sufficiently to make it
interesting. As you add more ash, your glaze might become quite runny.
Once you determine a good ratio of ash to glaze you can start adding
colorants. I am sure that you will discover some nice glazes. Another
possibility is to just dust some ash over a glazed
object and see what happens. Mia in ABQ
I noticed your Scottsdale address. I am going to be there in October for
the reunion of Old China Hands.
Joyce Donahue on mon 22 apr 02
I found a wonderful glaze I want to try......it contains volcanic ash.
This might be two basic questions (that once again I haven't a clue
on).......but here goes. #1 Will volcanic ash have an adverse effect on
the elements of my electric kiln. #2 The particles seem a little
large.......do I need to dip, or brush the glaze on, I'm fearful it will
clog my spray guy, but spraying is the method I prefer?
Dave Finkelnburg on tue 23 apr 02
Joyce,
Just read the reply from my friend Paul Lewing to your questions. He's
right on target about size of particles. Please keep in mind that Paul
fires to around cone 5. I have found melting volcanic ash fully at cone 10
is easier. Using the ash with other fluxes insures full melting. I screen
my volcanic ash at 80 mesh also.
Good glazing,
Dave Finkelnburg
-----Original Message-----
From: Joyce Donahue
To: CLAYART@LSV.CERAMICS.ORG
Date: Monday, April 22, 2002 9:27 PM
Subject: Volcanic Ash
>I found a wonderful glaze I want to try......it contains volcanic ash.
>This might be two basic questions (that once again I haven't a clue
>on).......but here goes. #1 Will volcanic ash have an adverse effect on
>the elements of my electric kiln. #2 The particles seem a little
>large.......do I need to dip, or brush the glaze on, I'm fearful it will
>clog my spray guy, but spraying is the method I prefer?
>
>___________________________________________________________________________
___
>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.
Dave Evans on tue 23 apr 02
Volcanic ash should not hurt your elements. It acts much like a =
feldspar. Any material with large particle size has the potential to =
clog spray equipment. I generally use a Navajo pumice, and have no =
problems with elements or spraying. The particle size is quite small. =
I have also used found pumice. The fine particles acted in the normal =
way, but the largest bits acted like a slightly melted sand in the =
glaze. Not what I was looking for, but could have it's uses. One thing =
to note about volcanic ash is that it seems to suck up a LOT of water. =
Pour in a normal amount of water and let the mix slake, then add small =
amounts at a time to bring it to the right consistency. =20
Hope you have fun with your experiments,
John Evans in San Diego
Paul Lewing on tue 23 apr 02
on 4/22/02 5:57 PM, Joyce Donahue at j1donahue@AOL.COM wrote:
> #1 Will volcanic ash have an adverse effect on
> the elements of my electric kiln. #2 The particles seem a little
> large.......do I need to dip, or brush the glaze on, I'm fearful it will
> clog my spray guy, but spraying is the method I prefer?
Joyce,
#1. Volcanic ash will not hurt your kiln. It's possible that burning too
much organic matter in an electric kiln can damage the elements, as when
you're firing poorly washed or unwashed wood as, but volcanic ash isn't like
that. In fact, it's not really an ash at all. It's just finely powdered
rock. And the chemical composition and particle size is wildly variable
depending on how far it was deposited from which volcano.
#2. You might want to screen the stuff before you spray it. Not only might
it clog your gun, it might also leave unmelted bits on the surface of your
work. Most volcanic ash is quite refractory. I usually screen my Mt. St.
Helens ash through an 80-mesh screen dry, and then after I mix up a glaze
containing it, I screen it again. Some of the particles that will pass
through dry seem to swell, and still leave small bumps.
Good luck,
Paul Lewing, Seattle
Joyce Donahue on sat 27 apr 02
Re: Volcanic Ash
Thanks to all who responded on my question..........I had sieved (60 not 80)
the glaze thus I chickened out and applied the glazes with a brush on three
pieces-------it was a very difficult application. The one with the
heaviest application came out very nicely with alittle bumpy
appearance...........which I liked........I will try it again.........and
probably spray it the next time..........It was definitly worth the
try..........Thanks again for all your responses.
John Peelle on tue 15 oct 02
Question?--Are Volcanic ash and pumice close enough to be substituted for
each other in a glaze recipe? I have a recipe that calls for volcanic ash
and I have pumice-----perhaps they are the same thing??
TIA,
Lyn
Leland G. Hall on wed 16 oct 02
Thats a good question, and I am interested in the answer because
I don't know it. I have however recently tried screened pumice in a clay
body as a substitute for grog. I had read in the clayart archives about
some native American potters doing this in the southwest, I think New
Mexico. The resulting clay was short, difficult to throw large, but as
suggested in the archives, the thermal shock properties were excellent. I
might try this again for large slab work, or a sculpture body, but not for
a throwing body. Sure would like to find a good use for pumice, as Mt.
Mazama (Crater Lake) and Newberry Crater has burried La Pine Basin in and
average of 8 feet of the stuff. Haven't really hunted for an ash deposit,
but pretty sure it's around somewhere.
Leland in La Pine, Oregon, USA, where I sure hope these sleeping giants
remain
so.
On
Tue, 15 Oct 2002 14:42:41 -0700, John Peelle wrote:
>Question?--Are Volcanic ash and pumice close enough to be substituted for
>each other in a glaze recipe? I have a recipe that calls for volcanic ash
>and I have pumice-----perhaps they are the same thing??
>
>TIA,
>Lyn
>
>___________________________________________________________________________
___
>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.
Paul Herman on wed 16 oct 02
Lyn,
All volcanic ashes and pumices are different from each other to some
degree, if they came from different eruptions. But you should test it
and see. Test, Test, Test...
My local volcanic ash makes a nice chocolate brown at cone 10:
V ash 67.5
wood ash 22.5
ball clay 10
good luck,
Paul Herman
Great Basin Pottery
423-725 Scott Road
Doyle, California 96109 US
potter@psln.com
----------
>From: John Peelle
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Volcanic ash
>Date: Tue, Oct 15, 2002, 2:42 PM
>
> Question?--Are Volcanic ash and pumice close enough to be substituted for
> each other in a glaze recipe? I have a recipe that calls for volcanic ash
> and I have pumice-----perhaps they are the same thing??
>
> TIA,
> Lyn
>
> ______________________________________________________________________________
> 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.
>
Paul Lewing on wed 16 oct 02
on 10/15/02 1:42 PM, John Peelle at peelles@QWEST.NET wrote:
> Are Volcanic ash and pumice close enough to be substituted for
> each other in a glaze recipe?
Probably. There's no real strict mineralogical definition for either one.
Try it and see.
Paul Lewing, Seattle
Tim Wilcox on thu 17 oct 02
I have been usung ash as temper(grog)in my Navajo Pottery for over a year
now. I new that Santa Clara potters used ash from the huge caldera that
makes the Santa clar and Jemez mtns. I found my sources out of interest
from my work (an archaeological firm. We have been looking at the use of
ash in the Kayenta Anaszi Black-on-white pottery. These pots were so well
made that you can almost tell that they are ash tempered just by looking at
how well the design was executed and how thin they are. Through Microprobe
analysis we found two different ashes. But they all accomlpish the same
thing. Tempering your clay without the added weight of sand. I just made
test tiles last week of many ash sources here in AZ and I did make some
with Pumice. I don't know about the chemical differeces yet but to me it
seems that pumice is just more fused and has bubbles. They are both white
and lightweight.
Michael McDowell on thu 17 oct 02
Are Vocanic Ash and Pumice close enough to substitute for each
other? Depends on both the ash and the pumice. If you consider that
the designations of ash and pumice have more to do with the physical
condition of the product rather than its chemical makeup. Volcanoes
are apt to bring a wide variety of materials to the earth's surface.
While this tends to be fairly constant from a single erruption, then
ash and pumice from the same erruption would tend to have the same
chemical makeup. But the chemical analyses of volcanic products can
change a bit over time from the same volcano, can vary from volcano
to volcano in the same region, and can vary markedly between
regions.
When formulas are posted to Clayart with "volcanic ash" as one of
the ingredients, and no remarks about the source of that product.
It's little more informative than simply to say "powdered igneous
rock". Of course, you can try it. You might like it! You might even
end up getting your material from the same source and reproduce
exactly. It would be a lot more helpful if people were more
forthcoming about where the source or who the supplier of the
"volcanic ash" might be. Sometimes, as is the case with most modern
erruptions of large scale, there are even chemical analyses of the
ash available.
From my experience, there is considerable difference between the
"volcanic ash" that is mined (i think) somewhere in the midwestern
U.S. and is available as such through commercial channels, and the
"volcanic ash" that can be found in the western U.S., deposited by
more recent western volcanoes. But Hawaiian volcanoes produce ash
and pumice with a very different chemical content from those of the
western U.S. as well. Yet the ash from the fairly recent erruption
of Mt. Pinatubo in the Phillipines was not that different from the
ash from Mt. St. Helens 1980 erruption.
All of this is just to say that the terms "volcanic ash" or "pumice"
tell us very little about the chemical makeup of a product or
ingredient. We need information as to its source if not a full
chemical analysis to give us any clues about reprodution or
substitutes. This should not be taken as discouraging
experimentation. It's just to point out that any attempt to follow a
formula that lists simply "volcanic ash" as an ingredient will be
very much an experiment.
Michael McDowell
Whatcom County, WA
Michael@McDowellPottery.com
http://www.McDowellPottery.com
Paul Herman on thu 17 oct 02
Michael,
First, let me say that the recipe I posted of my volcanic ash glaze was
only submitted as an example of how I use my "local" ash. As I said
before, they are all different, and you have to test them.
And since you would like to know more, the stuff is called "pozzolan"
and is mined a few miles from where I live, on the NW edge of the Great
Basin. A geologist working on the pozzolan happened by one day, and he
told me it was a "volcanic ash" type of material that settled in a lake.
It contains "some" alumina. Evidently it came from eruptions of Dixie
Mountain, a 13,000 ft peak 20 miles west of here. Dixie Mountain has
since eroded away to 8,000 ft.
The mine ( Western Pozzolan Corp) calcines the material at about 1600F,
then ballmills it and sells it as a specialised cement additive, for
making "hydraulic concrete". In my glaze I found it best to use a 50/50
mix of raw and calcined material. Next time I go up to the mine I will
ask them if they can provide me a chemical analysis of it, just for
curiosity, (yours and mine).
The deposits are up to 2,000 feet thick, so I guess I won't run out of
this material. So if any of you claybuds out there want to make the
exact same glaze, just stop on by sometime and I'll show you where you
can get a truckload. Bring a shovel.
But of course, then it becomes your glaze material, not mine, so don't
blame me if it doesn't come out right. (:o(
Best Wishes,
Paul Herman
Great Basin Pottery
423-725 Scott Road
Doyle, California 96109 US
potter@psln.com
----------
>From: Michael McDowell
> When formulas are posted to Clayart with "volcanic ash" as one of
> the ingredients, and no remarks about the source of that product.
> It's little more informative than simply to say "powdered igneous
> rock". Of course, you can try it. You might like it! You might even
> end up getting your material from the same source and reproduce
> exactly. It would be a lot more helpful if people were more
> forthcoming about where the source or who the supplier of the
> "volcanic ash" might be. Sometimes, as is the case with most modern
> erruptions of large scale, there are even chemical analyses of the
> ash available.
Joseph Herbert on thu 17 oct 02
I guess the short answer is maybe.
If you look at the digitalfire website there is a wonderful ;) article about
volcanic ash which indicates that it can have about any composition that
eruptive rocks can have. If you knew that the pumice was from the same
volcano as produced the ash, you could assume that the compositions were
close. That is probably not the case so you are left with analysis or glaze
testing.
The variability of natural materials is both a blessing and a curse for the
potter.
Joe
Snail Scott on fri 18 oct 02
At 11:04 AM 10/18/02 -0700, you wrote:
>I'm going to have to look up Doyle, CA on a map to see what "Great
>Basin" you are situated by. The one I am familiar with lies to the
>East of the Rocky Mts. Clearly, you can't mean that one.
>
Nope, the one and only Great Basin lies
between the Rockies and the Sierras.
East of the Rockies are the Great Plains.
-Snail
Michael McDowell on fri 18 oct 02
Paul,
First, let me apologize if my original post on this matter seemed a
bit brusqe. My proofreader/ editor was out that evening, leaving me
free to rant unrestrained. In any case I did not intend to target
anyone in particular, as there have been a few such casual
references to volcanic ash recently. I'm not even sure that I have
seen your original post on the subject, as my reading of Clayart is
rather spotty of late.
Thank you for the interesting background on the variety of volcanic
ash that you use in your glaze formula. Interesting that it is
calcined by the mine. It makes me think that it must be partway
converted to montmorillonite clay (like bentonite). Otherwise, there
would be no need for that step since the volcanic process itself
would take the material above red heat. It would be interesting to
see what the chemical analysis will reveal of its makeup.
Especially, since its commercial availability makes it widely
accessible.
I'm going to have to look up Doyle, CA on a map to see what "Great
Basin" you are situated by. The one I am familiar with lies to the
East of the Rocky Mts. Clearly, you can't mean that one.
Michael McDowell
Whatcom County, WA
Michael@McDowellPottery.com
http://www.McDowellPottery.com
>Date: Thu, 17 Oct 2002 17:16:35 -0700
>From: Paul Herman
>Subject: Re: Volcanic ash
>Michael,
>First, let me say that the recipe I posted of my volcanic ash glaze
was
>only submitted as an example of how I use my "local" ash. As I said
>before, they are all different, and you have to test them.
>And since you would like to know more, the stuff is called
"pozzolan"
>and is mined a few miles from where I live, on the NW edge of the
Great
>Basin. A geologist working on the pozzolan happened by one day, and
he
>told me it was a "volcanic ash" type of material that settled in a
lake.
>It contains "some" alumina. Evidently it came from eruptions of
Dixie
>Mountain, a 13,000 ft peak 20 miles west of here. Dixie Mountain
has
>since eroded away to 8,000 ft.
>The mine ( Western Pozzolan Corp) calcines the material at about
1600F,
>then ballmills it and sells it as a specialised cement additive,
for
>making "hydraulic concrete". In my glaze I found it best to use a
50/50
>mix of raw and calcined material. Next time I go up to the mine I
will
>ask them if they can provide me a chemical analysis of it, just for
>curiosity, (yours and mine).
>The deposits are up to 2,000 feet thick, so I guess I won't run out
of
>this material. So if any of you claybuds out there want to make the
>exact same glaze, just stop on by sometime and I'll show you where
you
>can get a truckload. Bring a shovel.
>But of course, then it becomes your glaze material, not mine, so
don't
>blame me if it doesn't come out right. (:o(
>Best Wishes,
>Paul Herman
>Great Basin Pottery
>423-725 Scott Road
>Doyle, California 96109 US
>potter@psln.com
LOGAN OPLINGER on sat 19 oct 02
Some years ago I put a small chunk of partly weathered volcanic tuff (hardend volcanic ash) into a bisque fire. It shrank about 10-15% and cracked a bit. Filed that information away mentally for a few years.
Some years later was working with some local earthenware clays that were extremely fine, tight & very plastic, not good for throwing. Tried adding fine grog to open clay & reduce amount of water needed to make pliable enough to throw. Grog worked, but upon bisque firing, fine cracks formed around particles of grog. Concluded grog did not shrink with the clay, since it had already been pre-fired. Then remembered my weathered volcanic ash experiment from years earlier. Ground some up to 60 mesh & finer, added up to 60% to clay. Body threw well, and bisque fired pots had very few fine cracks. Concluded ground up volcanic ash particles shrank along with the clay during firing, creating less stress on the clay.
Logan Oplinger
Another Pacific Island
Latitude: 13.5
Longitude: -144.7
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William Lucius on wed 26 jul 06
Somewhere I have a vial of Mt. St. Helens volcanic ash collected by a =
fellow archaeologist who just happened to be in graduate school in =
Pullman, Washington during the eruption. Hardly enough to design a =
glaze, so I managed to find another, much closer source. But rather =
than use it in a glaze I prefer to use it as grog. I cannot claim this =
innovation since a community of prehistoric Pueblo potters in Northern =
Arizona, who probably got tired of their pots cracking because of the =
quartz inversion problems associated with sand, were happily adding it =
to their clay around 1100 A.D. When viewed with a binocular microscope =
the stuff looks all the world like pulverized glass from neon light =
tubes.
So if you are in the Denver, Colorado area and would like to pick up a =
couple hundred pounds or so of this volcanic ash drop me a line and we =
will go see if is still there - hopefully no one has built a shopping =
center on top of it (yet).
William A. Lucius, Board President
Institute for Archaeological Ceramic Research
845 Hartford Drive
Boulder, CO 80305
iacr@msn.com
David Woof on wed 26 jul 06
Northern Arizona has highways cut through mounds ( hills) of ancient
volcanic ash. Ash is falling and blowing across the road whenever the wind
gets up. one can stop road side and scoop up buckets. one should stop at
the nearest hogan for permission and offer to pay for it.
David
_________________________________
_________________________________
David Woof Studio
Clarkdale, Arizona
Ph. 928-821-3747 Fax. 866-881-3461
________________________________
________________________________
peering over the edge, reverently taking an irreverent look at everything.
Peter H. Pache, Ph.D. on thu 2 aug 07
From: John Rodgers
<Los Alamos, and a few others around there, sit in the bowl of one of the biggest ancient volcanic calderas anywhere.>>
The Valles Caldera is located in the Jemez Mountains near Los Alamos, New Mexico: http://homepage.mac.com/davidneal/
I use volcanic ash from this eruption, which is called Navajo White and mined in Espanola (NM): http://www.crminerals.com/pages/navajo.php
Peter
NM
David Beumee on thu 9 aug 07
Dear William Lucius,
I have been away from CLAYART for several days and hope you receive this. I would very much like to get together and have a talk about ceramic archeology! I am a porcelain potter in Lafayette Colorado and am very interested in exploring and using found minerals in cone 10 glazes. I have recently come up with a granite glaze from the quarry at the head of Clear Creek canyon. Let's get together and talk!
David Beumee
Porcelain by David Beumee
806 East Baseline Road
Lafayette, CO
303-665-6925
www.davidbeumee.com
-------------- Original message ----------------------
From: William Lucius
>
> I seem to remember saying something about this subject before - check the
> archives!
>
> Thanks for the link for ground pumice from Espanola.
>
> As a ceramic archaeologist I am familiar with the use of crushed volcanic rock
> as tempering agents in the American Southwest. I know that studio potters have
> developed volcanic ash glazes, but I wonder how different forms of volcanic
> behave in glazes. In particular, has anyone developed a glaze using rhyolite?
> It is a volcanic rock similar in composition to granite and widely available in
> the Rio Grande Rift (which begins in Leadville in Colorado, extends south to El
> Paso in Texas and is responsible for most of the volcanic features along the
> way).
>
>
> William A. Lucius, Board President
> Institute for Archaeological Ceramic Research (IACR)
> 845 Hartford Drive
> Boulder, CO 80305
> iacr@msn.com
> www.instituteforceramicarchaeology.org> .org/>
> www.leuppkilnconference.org
> http://groups.msn.com/LeuppKilnConference> nce>
>
> ______________________________________________________________________________
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>
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Mike Gordon on wed 28 apr 10
One of the news shows I was watching during the Iceland eruption, had a
volcanic Geologist on, explaining why the cloud was so dangerous to fly
through, it was basically silica. Very abrasive on jet engine parts.
Mike Gordon
Rimas VisGirda on thu 16 jun 11
I was in Spokane shortly after Mt St Helens erupted. Folks at the Community=
College were rolling their bisqueware in puddles and firing to cone 10, no=
other additives, made a brown glaze somewhat similar to Albany. I've still=
got a 5 gallon bucket somewhere... -Rimas
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