Michele Hoskin on tue 6 apr 99
Hi everyone.
I finished up my supply of spodumene from Mile High Ceramics in Denver
Colorado recently. When I made up one of my favorite glazes with the new
batch of spodumene from Tucker's in Toronto, the beautiful multicolored
turquoise waxy surface was a flat solid turquoise. Very boring. I noticed
that the spodumene looked darker in colour and seemed more finely ground
(lots more dust!!!) than my previous batch and wondered if this was the
culprit. Any ideas? I miss my favorite glaze!
Thanks,
Michele Hoskin
Toronto
Lana Reeves on wed 7 apr 99
This is what I have been told. A few years ago, the mine that supplied
spodumene in North America closed. The new spodumene is imported from
Australia, which is why it costs so much more. It reacts differently, I
don't know enough about chemistry to explain why. I, too, am interested in
finding a substitute that is more like the "good old" spodumene. Thanks!
Lana in Somerville, MA
kilnkat@rcn.com =^..^=
-----Original Message-----
From: Michele Hoskin
To: CLAYART@LSV.UKY.EDU
Date: Tuesday, April 06, 1999 7:43 AM
Subject: Spodumene
>----------------------------Original message----------------------------
>
>Hi everyone.
>
>I finished up my supply of spodumene from Mile High Ceramics in Denver
>Colorado recently. When I made up one of my favorite glazes with the new
>batch of spodumene from Tucker's in Toronto, the beautiful multicolored
>turquoise waxy surface was a flat solid turquoise. Very boring. I noticed
>that the spodumene looked darker in colour and seemed more finely ground
>(lots more dust!!!) than my previous batch and wondered if this was the
>culprit. Any ideas? I miss my favorite glaze!
>
>Thanks,
>Michele Hoskin
>Toronto
Geoff Walker on wed 7 apr 99
Hello Michele,
I think your problem will have almost certainly been caused by the
particle size. The influence of this factor has always fascinated me (my
first ten years in clay were in reduction-fired earthenware), but it
mostly resides somewhere in the backblocks of my mind until something
triggers and re-ignites the thought. (Happened recently with silica ...!
Bugger! ...but thank you, God! LOL!)
I would certainly ask for an analysis, though. You deserve that at
least!
Best of luck.
Geoff.
http:/www.cronulla-pot.com.au/
Michele Hoskin wrote:
> ----------------------------Original
> message----------------------------
>
> Hi everyone.
>
> I finished up my supply of spodumene from Mile High Ceramics in Denver
>
> Colorado recently. When I made up one of my favorite glazes with the
> new
> batch of spodumene from Tucker's in Toronto, the beautiful
> multicolored
> turquoise waxy surface was a flat solid turquoise. Very boring. I
> noticed
> that the spodumene looked darker in colour and seemed more finely
> ground
> (lots more dust!!!) than my previous batch and wondered if this was
> the
> culprit. Any ideas? I miss my favorite glaze!
>
> Thanks,
> Michele Hoskin
> Toronto
Assumption Abbey on wed 7 apr 99
At 07:42 4/6/99 EDT, you wrote:
>----------------------------Original message----------------------------
>
>Hi everyone.
>
>I finished up my supply of spodumene from Mile High Ceramics in Denver
>Colorado recently. When I made up one of my favorite glazes with the new
>batch of spodumene from Tucker's in Toronto, the beautiful multicolored
>turquoise waxy surface was a flat solid turquoise. Very boring. I noticed
>that the spodumene looked darker in colour and seemed more finely ground
>(lots more dust!!!) than my previous batch and wondered if this was the
>culprit. Any ideas? I miss my favorite glaze!
>
>Thanks,
>Michele Hoskin
>Toronto
------------
Dear Michele,
Hi! I read your post in the morning mail (CLAYART). I fire to cone 9
- 10 reduction as well as
work in the lower cone ranges. If you would like to share your
muliticolored turquoise glaze I would
like to give it a test try in my next glaze firings? In my last kiln load
I had 75 test tiles and
these always yield something worth redoing. I work in stoneware and
Porcelain claybodies.
Llewellyn Kouba
ABBEY POTTERY>
Knox Steinbrecher on wed 7 apr 99
Michele
I had a similar experience with cobalt oxide. I use the oxide specifically
for the little blue specks. What I got with my new supply was solid blue.
If that was the effect I was after,I could have saved a buch of cash and
gotten carbonate. What a disappointment. I am still trying to find a
supplier who has the oxide that will give me the specks.
knox in Marietta Georgia where tonight's lottery is up to $190 million...and
me without a ticket (probably the only one in a 5 state radius)
Ron Roy on wed 7 apr 99
Hi Michele,
There are 3 kinds of Spod around - the old kind (mine now closed) from
Foote, Another kind being imported from Australia - probably by Hammil &
Gilespie and available in the US - the third kind - what you have is from
Tanko - supplied by Tuckers.
What you need to know is what kind you had before - we can then find the
analysis for it and reformulate your glaze for the new variety. Piece of
cake when we get both analysis.
Call the supplier you got the original kind from and we can start from there.
I'm leaving tomorrow for NY to do a workshop - be back on the 13th.
RR
>----------------------------Original message----------------------------
>
>Hi everyone.
>
>I finished up my supply of spodumene from Mile High Ceramics in Denver
>Colorado recently. When I made up one of my favorite glazes with the new
>batch of spodumene from Tucker's in Toronto, the beautiful multicolored
>turquoise waxy surface was a flat solid turquoise. Very boring. I noticed
>that the spodumene looked darker in colour and seemed more finely ground
>(lots more dust!!!) than my previous batch and wondered if this was the
>culprit. Any ideas? I miss my favorite glaze!
>
>Thanks,
>Michele Hoskin
>Toronto
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
Timothy Dean Malm on wed 7 apr 99
Greetings: I could be wrongly informed about Spodumene as presently
available. I believe it comes in chemical and industrial grades. I think
the industrial grade is more commonly available.Cheers Tim Malm
Earl Brunner on thu 8 apr 99
This one struck a cord, I have several glazes that had spodumene in them that I
used back in the 70's that I no longer use because the Spod is different and
gives different results. I remember that the old stuff was frothy and left a lot
of bubbles on the surface of the pots. I would be interested in reformulating t
recreate or duplicate those glazes. Would I just go with the old US spod
analysis to reformulate? Could do that with Insight comparing the two right?
Ron Roy wrote:
> ----------------------------Original message----------------------------
> Hi Michele,
>
> There are 3 kinds of Spod around - the old kind (mine now closed) from
> Foote, Another kind being imported from Australia - probably by Hammil &
> Gilespie and available in the US - the third kind - what you have is from
> Tanko - supplied by Tuckers.
>
> What you need to know is what kind you had before - we can then find the
> analysis for it and reformulate your glaze for the new variety. Piece of
> cake when we get both analysis.
>
> Call the supplier you got the original kind from and we can start from there.
>
> I'm leaving tomorrow for NY to do a workshop - be back on the 13th.
>
> RR
>
> >----------------------------Original message----------------------------
> >
> >Hi everyone.
> >
> >I finished up my supply of spodumene from Mile High Ceramics in Denver
> >Colorado recently. When I made up one of my favorite glazes with the new
> >batch of spodumene from Tucker's in Toronto, the beautiful multicolored
> >turquoise waxy surface was a flat solid turquoise. Very boring. I noticed
> >that the spodumene looked darker in colour and seemed more finely ground
> >(lots more dust!!!) than my previous batch and wondered if this was the
> >culprit. Any ideas? I miss my favorite glaze!
> >
> >Thanks,
> >Michele Hoskin
> >Toronto
>
> Ron Roy
> 93 Pegasus Trail
> Scarborough, Ontario
> Canada M1G 3N8
> Tel: 416-439-2621
> Fax: 416-438-7849
>
> Web page: http://digitalfire.com/education/people/ronroy.htm
--
Earl Brunner
bruec@anv.net
http://coyote.accessnv.com/bruec
Stephen Mills on thu 8 apr 99
This whole thread points up yet again just how important consistency in
material supply is. It's certainly one of our most important rules at
BPS
--
Steve Mills
Bath
UK
home e-mail: stevemills@mudslinger.demon.co.uk
work e-mail: stevemills@bathpotters.demon.co.uk
own website: http://www.mudslinger.demon.co.uk
BPS website: http://www.bathpotters.demon.co.uk
Michele Hoskin on fri 9 apr 99
Hi Ron.
It wasn't easy to track down because Mile Hi now gets it's Spodumene from
Australia. However, up until a year ago they claim that it came from New
York. I asked if it said Foote and he said "that's it!" but I thought
Foote was from Virginia according to Frank Tucker?!?
Does this help?
Thanks again,
Michele Hoskin
Toronto
-----Original Message-----
From: Ron Roy [SMTP:ronroy@total.net]
Sent: Wednesday, April 07, 1999 11:08 AM
To: CLAYART@LSV.UKY.EDU
Subject: Re: Spodumene
----------------------------Original message----------------------------
Hi Michele,
There are 3 kinds of Spod around - the old kind (mine now closed) from
Foote, Another kind being imported from Australia - probably by Hammil &
Gilespie and available in the US - the third kind - what you have is from
Tanko - supplied by Tuckers.
What you need to know is what kind you had before - we can then find the
analysis for it and reformulate your glaze for the new variety. Piece of
cake when we get both analysis.
Call the supplier you got the original kind from and we can start from
there.
I'm leaving tomorrow for NY to do a workshop - be back on the 13th.
RR
>----------------------------Original message----------------------------
>
>Hi everyone.
>
>I finished up my supply of spodumene from Mile High Ceramics in Denver
>Colorado recently. When I made up one of my favorite glazes with the new
>batch of spodumene from Tucker's in Toronto, the beautiful multicolored
>turquoise waxy surface was a flat solid turquoise. Very boring. I
noticed
>that the spodumene looked darker in colour and seemed more finely ground
>(lots more dust!!!) than my previous batch and wondered if this was the
>culprit. Any ideas? I miss my favorite glaze!
>
>Thanks,
>Michele Hoskin
>Toronto
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
Ron Roy on thu 15 apr 99
Hi Michele,
I'm back.
Foote Minerals is/was in MA but they would mine materials where they would
find them so both may be right.
The analysis I use for Foote spod is as follows - notice the high iron content.
SiO2 - 63.0
Al2O3 - 24.8
Fe2O3 - 2.28
Li2O - 5.78
Na2O - 0.6
K2O - 1.18
LOI - 0.20
The analysis I use for Tanko Spod is
SiO2 - 66.0
Al2O3 - 25.5
Fe2O3 - 0.09
Li2O - 7.20
Na2O - 0.225
K2O - 0.25
P2O5 - 0.25
MnO2 - 0.035
LOI - 0.20
This should be an easy problem to solve - but I need your glaze recipe - I
can do it with the extra iron and without - RR
>----------------------------Original message----------------------------
>Hi Ron.
>It wasn't easy to track down because Mile Hi now gets it's Spodumene from
>Australia. However, up until a year ago they claim that it came from New
>York. I asked if it said Foote and he said "that's it!" but I thought
>Foote was from Virginia according to Frank Tucker?!?
>
>Does this help?
>
>Thanks again,
>Michele Hoskin
>Toronto
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
Michele Hoskin on wed 21 apr 99
Hi Ron.
Thanks again for responding. My turquoise glaze recipe is:
Dolomite 8
Spodumene 5
Strontium Carbonate 25
Potash Feldspar 50
EPK 12
Add:
Copper Carbonate 2
The potash feldspar I am now using is G-200. Prior to this I used some
from Mile Hi Ceramics in Denver as well. Any chance this also might be
affecting my final glaze?
Michele Hoskin
Toronto
-----Original Message-----
From: Ron Roy [SMTP:ronroy@total.net]
Sent: Thursday, April 15, 1999 7:54 AM
To: CLAYART@LSV.UKY.EDU
Subject: Re: Spodumene
----------------------------Original message----------------------------
Hi Michele,
I'm back.
Foote Minerals is/was in MA but they would mine materials where they would
find them so both may be right.
The analysis I use for Foote spod is as follows - notice the high iron
content.
SiO2 - 63.0
Al2O3 - 24.8
Fe2O3 - 2.28
Li2O - 5.78
Na2O - 0.6
K2O - 1.18
LOI - 0.20
The analysis I use for Tanko Spod is
SiO2 - 66.0
Al2O3 - 25.5
Fe2O3 - 0.09
Li2O - 7.20
Na2O - 0.225
K2O - 0.25
P2O5 - 0.25
MnO2 - 0.035
LOI - 0.20
This should be an easy problem to solve - but I need your glaze recipe - I
can do it with the extra iron and without - RR
>----------------------------Original message----------------------------
>Hi Ron.
>It wasn't easy to track down because Mile Hi now gets it's Spodumene from
>Australia. However, up until a year ago they claim that it came from New
>York. I asked if it said Foote and he said "that's it!" but I thought
>Foote was from Virginia according to Frank Tucker?!?
>
>Does this help?
>
>Thanks again,
>Michele Hoskin
>Toronto
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
Ron Roy on sat 24 apr 99
Hi Michele,
I'm outa time again - off to do a glaze workshop - be back monday - remind
me then to do this - I'll only be in here for two days so don't be
disappointed if I don't get time then - will have more time later.
RR
>Thanks again for responding. My turquoise glaze recipe is:
>
>Dolomite 8
>Spodumene 5
>Strontium Carbonate 25
>Potash Feldspar 50
>EPK 12
>
>Add:
>Copper Carbonate 2
>
>
>The potash feldspar I am now using is G-200. Prior to this I used some
>from Mile Hi Ceramics in Denver as well. Any chance this also might be
>affecting my final glaze?
>
>Michele Hoskin
>Toronto
>
>-----Original Message-----
>From: Ron Roy [SMTP:ronroy@total.net]
>Sent: Thursday, April 15, 1999 7:54 AM
>To: CLAYART@LSV.UKY.EDU
>Subject: Re: Spodumene
>
>----------------------------Original message----------------------------
>Hi Michele,
>
>I'm back.
>
>Foote Minerals is/was in MA but they would mine materials where they would
>find them so both may be right.
>
>The analysis I use for Foote spod is as follows - notice the high iron
>content.
>
>SiO2 - 63.0
>Al2O3 - 24.8
>Fe2O3 - 2.28
>Li2O - 5.78
>Na2O - 0.6
>K2O - 1.18
>LOI - 0.20
>
>The analysis I use for Tanko Spod is
>
>SiO2 - 66.0
>Al2O3 - 25.5
>Fe2O3 - 0.09
>Li2O - 7.20
>Na2O - 0.225
>K2O - 0.25
>P2O5 - 0.25
>MnO2 - 0.035
>LOI - 0.20
>
>This should be an easy problem to solve - but I need your glaze recipe - I
>can do it with the extra iron and without - RR
>
>
>>----------------------------Original message----------------------------
>>Hi Ron.
>>It wasn't easy to track down because Mile Hi now gets it's Spodumene from
>>Australia. However, up until a year ago they claim that it came from New
>>York. I asked if it said Foote and he said "that's it!" but I thought
>>Foote was from Virginia according to Frank Tucker?!?
>>
>>Does this help?
>>
>>Thanks again,
>>Michele Hoskin
>>Toronto
>
>
>
>Ron Roy
>93 Pegasus Trail
>Scarborough, Ontario
>Canada M1G 3N8
>Tel: 416-439-2621
>Fax: 416-438-7849
>
>Web page: http://digitalfire.com/education/people/ronroy.htm
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
Emily Muench on mon 28 jun 99
Recently I mixed 1000 grams of the simple glaze recomended by Pete Pinell in
an article appearing in Clay Times.....I discovered I have two different
colored spodumenes in my "at home" studio! The gray, and I also found 5lbs
labeled "spodumene" that is white..........could this be mislabeled? or is
spodumene white also? Check your spod and let me know.....thanks, Em
Lori Pierce on tue 29 jun 99
Hi Em...mine is white! My spodumene, that is.I noticed that one of the
catalogues specified their spodumene was from Australia...but no mention of
color. The gerus will know. Lori in new Port Richey
-----Original Message-----
From: Emily Muench
To: CLAYART@LSV.UKY.EDU
Date: Monday, June 28, 1999 9:19 AM
Subject: Re: Spodumene
>----------------------------Original message----------------------------
>Recently I mixed 1000 grams of the simple glaze recomended by Pete Pinell
in
>an article appearing in Clay Times.....I discovered I have two different
>colored spodumenes in my "at home" studio! The gray, and I also found 5lbs
>labeled "spodumene" that is white..........could this be mislabeled? or is
>spodumene white also? Check your spod and let me know.....thanks, Em
>
Pottery by Dai on tue 29 jun 99
Hi, Em - I've had two different colors of spod as well. It used to be a
greyish color, and it was in a production recipe I had that was incredible
and a big seller---then spodumene started coming in white, and the recipe
has never been the same. What a blow! So, expect some changes in your
glaze when you change spods....:(
Dai Scott - Kelowna, B.C., home of the "Instantly Disappearing Summer"
potterybydai@home.com
Craig Martell on tue 29 jun 99
Hi:
I have two kinds of spodumene in the studio. Chemical grade which is a
darker grayish green and Ceramic grade which is white. I've always found
the Ceramic grade to be the better of the two choices. If you fire to cone
10 Red, do fusions of each of the spars. If the darker one fires out to a
fused opaque dirty brown matt glass, it's probably Chemial grade. The white
should fire out to a milky opaque white matt glass or a very dry orange if
it doesn't get enough temp to fuse. Spodumene doesn't have a set melt point
or fusion temp and this is usually classified as a "temperature range" where
melt is likely to occur.
regards, Craig Martell in Oregon
Ron Roy on tue 29 jun 99
There seems to be three different kinds of spod around these days - the old
Foote spod which has iron and other impurities in it - It's no longer mined
- that's the grey stuff.
Then there is some from Australia and some from Canada - Tanko. These last
two are similar in chemical make up and look white.
Which was Pete's made with? I would guess the Foote because it is what was
available in NA for a long time - the others are more recent - could be
wrong though - best to do a small test of each.
>----------------------------Original message----------------------------
>Recently I mixed 1000 grams of the simple glaze recomended by Pete Pinell in
>an article appearing in Clay Times.....I discovered I have two different
>colored spodumenes in my "at home" studio! The gray, and I also found 5lbs
>labeled "spodumene" that is white..........could this be mislabeled? or is
>spodumene white also? Check your spod and let me know.....thanks, Em
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
Michael Banks on thu 4 nov 99
Thanks for the spodumene analysis Scott. One small point, the new high
grade spodumene is mined from the Greenbushes deposit in Western Australia,
which is I believe the worlds largest deposit. Not in New Zealand
unfortunately.
Michael Banks,
Nelson,
New Zealand
> ----------------------------Original message----------------------------
> Hi Earl,
> Since many potters are concerned with the difference between the
> old spodumene (gray) and the new spodumene (white), I ran an analysis of
> both on the xray fluorescence. The new spodumene that is sold here
> (northern California) is mined in New Zealand. The XRF does not detect
the
> element lithium because it is too light. Anyway, the main difference
> between the two is that the new spodumene is much more pure than the old.
> The old spodumene contains from 0.5 to 1.5% each of sodium, potassium,
> calcium, phosphorus, and iron that is not found in the new spodumene, and
> it also has more trace elements. These extra elements can most likely be
> attributed to other feldspars usually found in association with spodumene,
> which are difficult to separate in the mining process.
> Because the XRF does not analyze for lithium, I ran a sample of
the
> new spodumene on the Xray diffraction, which tells the minerals that are
> present. Sure enough, the new spodumene really is spodumene
>
> Scott C. North
> Geology Department
> Humboldt State University
> Arcata, CA 95521
> phone: (707) 826-3210
> FAX: (707) 826-5241
>
Tetsuya Shimano on thu 9 dec 99
i have another question. a friend of mine who is a japanese potter asked me
about "western style" shino recipes the other day. he is very interested in
warren mackenzie's shino. i have his shino recipe, but it has spodumene in
it. i cannot find any translation into japanese/ sustitution of spodumene in
japan. i looked for the "word" in a ceramics translation book, but it
deesn't have spodumene. if i know the chemical composition of spodumene, i
can tell him about it.....or should i give him the other shino recipes w/o
spodumine? or should i send some spodumene to japan? i also remember a
story that warren imported "mashiko" clay from japan to make his kaki glaze.
now, i think, he uses "synthetic mashiko kaki glaze." anyway,it's so
difficult to translate "words" into another language....any answers???
t
Puddy & Co. on thu 23 mar 00
Hello everybody and especially the glaze gurus!
Recently I have been using a glaze that contains about 20% of spodumene.
I love it for the deep, glossy colours and would like to be able to
continue use it on the "commercial" pots. Application of it though
gives me quite a hard time. The glaze in the bucket acts a little bit
like coca-cola in a can: when I shake it, bubbles come up an run around
the surface. As you can guess - the same thing happens in a glazed bowl.
This leaves me with very nicely glazed bottoms ,and tops, especially
rims, full of patches and splotches. Smoothing it out when dry does not
really do the job. I understand that it is a surface tension problem. I
called my supplier and - no, there is no remedy for it other than
recalculate the whole thing using Lithium Carbonate. I trust him. I am
going to start at it tonight, but maybe there is someone out there who
has a miraculous advice to this problem.?
By the way - I am new here but I have been using the Clayart for quite a
while as a source of information and for enjoyment. I have gone through
the beginnings of pottery by myself and in isolation from the potters
community. I have never had a chance to see a potter at work, other than
myself. You have no idea how wonderful it is to have access not only the
technical advice but also to the whole range of ideas and attitudes. You
are great!
Hanna Lewandowski
Auburn, Ontario
Ron Roy on mon 27 mar 00
Hi Hanna,
I do not recommend recalculating with lithium carb. That will only
lead to other problems which will be worse.
I suggest you wash the spod before you add it to the glaze - there is
probably some agent added for some reason that results in the bubbles.
Weigh out the spod first - add a lot of water - let sit over night
aqnd pour off the top water - do this a couple of times - then add
the rest of the Ingredients and mix as usual. This should get rid of
most of the problem.
RR
>----------------------------Original message----------------------------
>Hello everybody and especially the glaze gurus!
>
>Recently I have been using a glaze that contains about 20% of spodumene.
>I love it for the deep, glossy colours and would like to be able to
>continue use it on the "commercial" pots. Application of it though
>gives me quite a hard time. The glaze in the bucket acts a little bit
>like coca-cola in a can: when I shake it, bubbles come up an run around
>the surface. As you can guess - the same thing happens in a glazed bowl.
>This leaves me with very nicely glazed bottoms ,and tops, especially
>rims, full of patches and splotches. Smoothing it out when dry does not
>really do the job. I understand that it is a surface tension problem. I
>called my supplier and - no, there is no remedy for it other than
>recalculate the whole thing using Lithium Carbonate. I trust him. I am
>going to start at it tonight, but maybe there is someone out there who
>has a miraculous advice to this problem.?
>
>By the way - I am new here but I have been using the Clayart for quite a
>while as a source of information and for enjoyment. I have gone through
>the beginnings of pottery by myself and in isolation from the potters
>community. I have never had a chance to see a potter at work, other than
>myself. You have no idea how wonderful it is to have access not only the
>technical advice but also to the whole range of ideas and attitudes. You
>are great!
>
>
>Hanna Lewandowski
>Auburn, Ontario
Ron Roy
93 Pegasus Trail,
Scarborough, Ontario
Canada. M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Marni Turkel on wed 29 mar 00
Ron Roy suggested to Hanna that she should wash her spodumene to stop a
glaze batch from bubbling in the bucket. A year or two ago I was having
trouble with a glaze foaming when I stirred it up or even dipped, Ron gave
me the same advice (I actually just skimmed off the water in the existing
glaze batch several times) and it did help. I decided to try buying a fresh
batch of spodumene to see if anything had changed since I had last bought
it, and it had. The new spod. was a different texture and whiter than the
previous and when I mixed a test batch of the glaze, it didn't foam at all.
If you really like the glaze, check out different sources.
Hanna, I don't have your e-mail or I would post directly to you also.
Marni
Marni Turkel
Stony Point Ceramic Design
2080 Llano Rd 1B
Santa Rosa, CA 95407
Pottery: 707-579-5567
Office: 707-579-9511
Fax: 707-579-1116
Karen Sullivan on fri 8 sep 00
I have a number of shino glazes that use spodumene.
I fire cone 11, reduction.
I have been using the old supply, and since last year understand that the
mine in the United States was closed. Now we live with a new supplier from
Australia for spodumene.
I have noticed a significant difference in the results of my shinos.
What do I do? I have been guarding my limited supply.
Visually I notice the old spod has a grey/blue color, the new stuff is
pearly white.
Pick a shino formula that uses spodumene, any formula...
The question is, what was the unity formula for the old supply of spod and
how do I adapt to the new supply.
Many thanks
bamboo,karen
Hank Murrow on sat 9 sep 00
Karen wrote;
>I have a number of shino glazes that use spodumene.
>I fire cone 11, reduction.
>I have been using the old supply, and since last year understand that the
>mine in the United States was closed. Now we live with a new supplier from
>Australia for spodumene.
>I have noticed a significant difference in the results of my shinos.
>What do I do? I have been guarding my limited supply.
>Visually I notice the old spod has a grey/blue color, the new stuff is
>pearly white.
>Pick a shino formula that uses spodumene, any formula...
>The question is, what was the unity formula for the old supply of spod and
>how do I adapt to the new supply.
Dear Karen; I have in my studio an inventory of seven distinctively
different Spodumenes. The one I currently prefer for Shinos is distributed
from Canada; but I am not sure where it is actually mined. It is referred
to as Low Melt Spodumene, and has "Tanco" on the bag. I buy it from
Georgies in Portland. If you contact me off-list, I will send my Mole
formula for it. Hank in Eugene
Karen Sullivan on sat 9 sep 00
SO...I looked at digitalfire's material database for spodumene.
Is the analsis listed on the site the current Gwalia Australian mine for
spodumene or is it the old Goote mineral spodumene. I suppose I could look
in historical listings for the info.
I am looking for strategies for adapting my spod use in shino.
thanks, although somewhat impatient, for which I apologize profusely.
bamboo, karen
I do appreciate the fact that mines change, I am only looking for ways to
adapt and change with the change. Does that make sense.
I am interested in other people's experience with shino/spodumene.
iandol on sun 10 sep 00
Dear Karen
This is always a hard call. A good reminder that we live in a World of =
finite resources.
A couple of suggestions.
1 Have your old stuff analysed to find out what the other elements are =
which contaminate it and then use a glaze calc program to reinvent your =
old recipes with the Australian Spod and compounds which contain the =
residual elements.
2 Start from scratch with one of the many blend matrix patterns, with =
the Aussie Spod on one axis, following the principles of making a good =
Shino
Remember, a glaze can always be described in objective terms. Knowledge =
of how those qualities are created is in the data bank somewhere. So it =
becomes possible to design a glaze to meet the specification. And I =
believe that as the future rolls towards us and resources diminish we =
will need to learn how to design glazes from first principles. Which is =
what seems to happening following the demise of good old GB.
Regards,
Ivor Lewis. Redhill, South Australia.
ARTISTINSC@AOL.COM on mon 2 oct 00
Has anyone used the chemical spodumene? I ordered spodumene and bone ash from
from Highwater a few years ago in 100# bag but got chemical spodumene and a
form of bone ash like I'd never seen, definitely not ready to use. The bill
for these babies knocked my socks off too.
Margaret
Keiko Suga & Noel Oard Mapstead on tue 3 oct 00
i use spudomene for wet fire raku
ARTISTINSC@AOL.COM wrote:
> Has anyone used the chemical spodumene? I ordered spodumene and bone ash from
> from Highwater a few years ago in 100# bag but got chemical spodumene and a
> form of bone ash like I'd never seen, definitely not ready to use. The bill
> for these babies knocked my socks off too.
> Margaret
>
> ______________________________________________________________________________
> 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.
Daniel Dermer on sun 20 apr 03
Hannah,
Here is a recipe for "Spodumene" that I've used with success. It comes
from the recipes section of an old Ceramics Monthly article on the ceramics
program at Sun Valley:
Spodumene
Dolomite 22
Whiting2
Custer 30
Spodumene 20
EPK 26
100
Add
Tin Oxide 6
Hank Murrow on fri 24 dec 04
On Dec 24, 2004, at 5:12 PM, Mike Gordon wrote:
> Hi,
> I have been using a very white, sugar crystal like Spodumene for a year
> now and my base glaze at cone 6 is a white in oxydation, with a blueish
> tinge in light reduction, My problem is with the new batch, it is a
> gray and turns my glaze a gray, not white. The new batch fires the same
> as in glazed surface and everything is the same except for the color. I
> don't have a manufactures name on the bag since they were in 2 10lb, 1
> 5lb. bags. Monday I'll check with Leslie's Ceramics in Berkeley, Calif.
> and see if they can help. Maybe another plant will have the old kind.
> Does anybody out there use Spodumene? If so what color and texture is
> yours?? I'll show you mine if you'll show me yours. ;-) My other
> thought is, if I can't find the old kind, is to introduce the new gray
> kind into my existing supply and just live with it. What do you
> think???
Dear Mike;
The first thing you can do is pack a thimble full of the raw material,
and then turn it over onto a piece of bisque, being careful to not
disturb it as you lift the thimble off. Fire the sample along with the
old material prepared the same way and compare their appearance after
the fire. One is apt to be darker, perhaps one will be pink. The fired
color and melt is what you need to reference. The appearance in the bag
is not very useful.
Goes for nearly any material you wish to use.
Cheers, Hank
www.murrow.biz/hank
Mike Gordon on fri 24 dec 04
Hi,
I have been using a very white, sugar crystal like Spodumene for a year
now and my base glaze at cone 6 is a white in oxydation, with a blueish
tinge in light reduction, My problem is with the new batch, it is a
gray and turns my glaze a gray, not white. The new batch fires the same
as in glazed surface and everything is the same except for the color. I
don't have a manufactures name on the bag since they were in 2 10lb, 1
5lb. bags. Monday I'll check with Leslie's Ceramics in Berkeley, Calif.
and see if they can help. Maybe another plant will have the old kind.
Does anybody out there use Spodumene? If so what color and texture is
yours?? I'll show you mine if you'll show me yours. ;-) My other
thought is, if I can't find the old kind, is to introduce the new gray
kind into my existing supply and just live with it. What do you
think??? Thanks and a Merry Christmas to all, Mike Gordon
Daniel Semler on sat 25 dec 04
Hi Mike,
I use it. The stuff I use is very white and sparkles in the sunlight. Its the
Australian spod from Sons of Gwalia. My most recent stuff comes from Clay
Planet in San Jose, but its from the same producer. The new stuff you have, I
don't know what it is. I would be interested though as I know people who prefer
the less pure spods for some shinos, rather than the purer Aussie stuff.
Thanx
D
Jo Smith on sat 25 dec 04
Mike,
I have had the opposite problem with Spodumene, I cannot get the rust color
standby glaze with the "white" spodumene w/o adding yellow ochre. I think
my last batch came from Laguna. I loved the gray sparkling or as one
supplier called it "dirty". I bought all of it that he had. Since spod. is
a blend very different results will come from each batch. Keep looking and
let me know the source of the gray.
Good Cheer,
Jo
js6pottery@ozarkisp.net
> Hi,
> I have been using a very white, sugar crystal like Spodumene for a year
> now and my base glaze at cone 6 is a white in oxydation, with a blueish
> tinge in light reduction, My problem is with the new batch, it is a
> gray and turns my glaze a gray, not white. The new batch fires the same
> as in glazed surface and everything is the same except for the color. I
> don't have a manufactures name on the bag since they were in 2 10lb, 1
> 5lb. bags. Monday I'll check with Leslie's Ceramics in Berkeley, Calif.
> and see if they can help. Maybe another plant will have the old kind.
> Does anybody out there use Spodumene? If so what color and texture is
> yours?? I'll show you mine if you'll show me yours. ;-) My other
> thought is, if I can't find the old kind, is to introduce the new gray
> kind into my existing supply and just live with it. What do you
> think??? Thanks and a Merry Christmas to all, Mike Gordon
Ron Roy on sun 26 dec 04
Hi Mike,
Thats iron contamination - probably a different kind of Spod - maybe Tanko.
What you want is the Aussi kind.
RR
>I have been using a very white, sugar crystal like Spodumene for a year
>now and my base glaze at cone 6 is a white in oxydation, with a blueish
>tinge in light reduction, My problem is with the new batch, it is a
>gray and turns my glaze a gray, not white. The new batch fires the same
>as in glazed surface and everything is the same except for the color. I
>don't have a manufactures name on the bag since they were in 2 10lb, 1
>5lb. bags. Monday I'll check with Leslie's Ceramics in Berkeley, Calif.
>and see if they can help. Maybe another plant will have the old kind.
>Does anybody out there use Spodumene? If so what color and texture is
>yours?? I'll show you mine if you'll show me yours. ;-) My other
>thought is, if I can't find the old kind, is to introduce the new gray
>kind into my existing supply and just live with it. What do you
>think??? Thanks and a Merry Christmas to all, Mike Gordon
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
mailtoandrew@FSMAIL.NET on sun 26 dec 04
Hi Mike,
The problems with supply could be related to Sons of Gwalia, the
Australian based world biggest producer of spodumene, going into voluntary
administration earlier this year.
I dont know if SoG are currently mining but perhaps the different material
you described was your suppliers best alternative from another source?
Regards,
Andrew
Lili Krakowski on thu 27 jan 05
Mel is right about myths and rumors. I am under the impression that I =
heard this bit correctly. Correct me please if I am wrong. =20
I have been told that people on lithium medication often take a =
maximally safe amount. Meaning that another tidge would do them harm, =
be fatal, who knows. Therefore there is no lithium in my studio so =
that if any gets in the air or on the floor, visiting friends on meds =
would still be ok.
I HAVE NOT read a single word about Spodumene, Lepidolite, or Petalite, =
and whether they too would be a danger if inhaled. I have not found a =
single word about them. So I will shun till I know.
It isn't so much that life is short, that bugs me. It bugs me when it =
is thrown away.
Lili Krakowski
Be of good courage
Paul Lewing on fri 28 jan 05
on 1/27/05 4:36 PM, Lili Krakowski at mlkrakowski@CITLINK.NET wrote:
> I HAVE NOT read a single word about Spodumene, Lepidolite, or Petalite, =
> and whether they too would be a danger if inhaled. I have not found a =
> single word about them. So I will shun till I know.
Only about 7.6% of spodumene is lithium oxide. IF that's a form of lithium
that can affect that medication, and IF your body can separate the lithium
from the rest of the mineral, and IF it does actually work that way with
medications, you'd have to be snorting it like cocaine to get enough lithium
from spodumene to do anything. Shun it because it's a silicate if you must,
but then you have to shun clay, too. Lithium carbonate, on the other hand,
might be a different story- maybe. No one knows.
Paul Lewing, Seattle
David Hewitt on fri 28 jan 05
Lili is of course quite right about the hazard of silica dust.
That is the reason why it is supplied with a percentage of water rather
than as a dry powder and so reduces the hazard. As is also Cornish stone
in the UK.
David
In message , Lee Love writes
>Lili Krakowski wrote:
>
>>I HAVE NOT read a single word about Spodumene, Lepidolite, or
>>Petalite, and whether they too would be a danger if inhaled. I have
>>not found a single word about them. So I will shun till I know.
>>
>>
>
> This is one of the biggest myths we see spread on Clay Art:
>is that there are "safe" silicates as far as inhalation goes. .
>
> Potters work with silicates because we work with
>clay. Silicosis is our number one health danger in the studio. The
>best way to protect our health is to keep silicates out of the air.
>
> One of the positive aspects of traditional wet mixing of
>glazes is that you handle all the dry materials outside, in the open
>air. They are wet mixed outside in large batches that are combined as
>needed for glaze or slip. This helps keep dust from glaze mixing out
>of the studio. Wet mixing (the combining of kaolin, ball clay, ash,
>etc) in the form of slurry can be done inside, but there is minimal
>chance of glaze dust getting in the air from the wet ladle.
>
> As far as lithium poisoning goes, our very own Edouard
>has written about that. You can read about it here:
>
>http://www.digitalfire.ab.ca/cermat/education/164.html
>*
--
David Hewitt
Web:- http://www.dhpot.demon.co.uk
Antoinette Badenhorst on fri 28 jan 05
In my mind, anything that is handled irresponsibly can be hazardous....even
eating a banana! (meant in a light way)
Antoinette.
----- Original Message -----
From: "Lili Krakowski"
To:
Sent: Thursday, January 27, 2005 6:36 PM
Subject: Spodumene
Mel is right about myths and rumors. I am under the impression that I heard
this bit correctly. Correct me please if I am wrong.
I have been told that people on lithium medication often take a maximally
safe amount. Meaning that another tidge would do them harm, be fatal, who
knows. Therefore there is no lithium in my studio so that if any gets in
the air or on the floor, visiting friends on meds would still be ok.
I HAVE NOT read a single word about Spodumene, Lepidolite, or Petalite, and
whether they too would be a danger if inhaled. I have not found a single
word about them. So I will shun till I know.
It isn't so much that life is short, that bugs me. It bugs me when it is
thrown away.
Lili Krakowski
Be of good courage
______________________________________________________________________________
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.
Louis Katz on fri 28 jan 05
Daily dosage for Lithium for Bipolar disorder is around 300-450
milligrams. While there is little margin between safe and therapeutic
doses
(http://www.gettingwell.com/drug_info/nmdrugprofiles/nutsupdrugs/
lit_0161.shtml) inhaling much (10 milligrams?) of lithium carbonate
seems difficult. I would be more concerned with silicosis if your
studio is that dusty. Perhaps Edouard can chime in here.
I would assume that some of the lithium in Spodumene, Lepidolite, and
Petalite would be leached in stomach acids.
Louis
A fun place to visit is http://www.unwords.com/
On Jan 27, 2005, at 6:36 PM, Lili Krakowski wrote:
> Mel is right about myths and rumors. I am under the impression that I
> heard this bit correctly. Correct me please if I am wrong.
>
> I have been told that people on lithium medication often take a
> maximally safe amount. Meaning that another tidge would do them harm,
> be fatal, who knows. Therefore there is no lithium in my studio so
> that if any gets in the air or on the floor, visiting friends on meds
> would still be ok.
>
> I HAVE NOT read a single word about Spodumene, Lepidolite, or
> Petalite, and whether they too would be a danger if inhaled. I have
> not found a single word about them. So I will shun till I know.
>
> It isn't so much that life is short, that bugs me. It bugs me when it
> is thrown away.
> Lili Krakowski
>
> Be of good courage
>
> _______________________________________________________________________
> _______
> 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.
>
>
http://falcon.tamucc.edu/~lkatz/LK/index.htm
Lee Love on fri 28 jan 05
Lili Krakowski wrote:
>I HAVE NOT read a single word about Spodumene, Lepidolite, or Petalite, and whether they too would be a danger if inhaled. I have not found a single word about them. So I will shun till I know.
>
>
This is one of the biggest myths we see spread on Clay Art:
is that there are "safe" silicates as far as inhalation goes. .
Potters work with silicates because we work with
clay. Silicosis is our number one health danger in the studio. The
best way to protect our health is to keep silicates out of the air.
One of the positive aspects of traditional wet mixing of
glazes is that you handle all the dry materials outside, in the open
air. They are wet mixed outside in large batches that are combined as
needed for glaze or slip. This helps keep dust from glaze mixing out
of the studio. Wet mixing (the combining of kaolin, ball clay, ash,
etc) in the form of slurry can be done inside, but there is minimal
chance of glaze dust getting in the air from the wet ladle.
As far as lithium poisoning goes, our very own Edouard
has written about that. You can read about it here:
http://www.digitalfire.ab.ca/cermat/education/164.html
*
> *The only lithium compound that is reported as a severe hazard is
> lithium hydride (LiH), which is used as a condensing agent in chemical
> synthesis with acid esters and ketones, as a dessicant (a reducing
> agent), and as a hydrogen source.
> The hydride is a severe irritant to skin and mucous membranes because
> it becomes lithium hydroxide when in contact with moisture of these
> structures.(3)
> *
> * by**Edouard Bastarache M.D. (Occupational & Environmental Medicicne)
> **Author of "Substitutions for Raw Ceramics Materials"*
> **
> --
*
Lee in Mashiko, Japan http://mashiko.org
http://www.livejournal.com/users/togeika/ WEB LOG
http://public.fotki.com/togeika/ Photos!
Gail Dapogny on mon 10 apr 06
Ron and others,
Our guild has just received, in a shipment, "Spodumene Concentrate",
75 micron. Apparently the lithium content is somewhat higher. It is
very white, while our previous spodumene was light greyish. It says
that it is a product of Australia.
Should we be using this material differently from non-concentrate
spodumene? Should we compensate in some way? Is the old non-
concentrate spodumene still generally available?
Any and all help will be greatly appreciated.
thanks,
Gail Dapogny in Ann Arbor
Paulette Carr on tue 11 apr 06
Gail,
I have had the same experience. My previous stock of spodumene was
grey and flour-like in appearance. This new spodumene is very white
and crystalline in appearance, although they both feel soft, rather
than grainy when rubbed between two fingers ... and no!, I did not
taste them (ha,ha, ha!). My supplier told me that this material
comes from Australia. I made glazes from both (as I had a very small
amount of the previous stock), and found that the glaze prepared from
the new Spodumene shivered, white the one prepared from the old
spodumene did not. Perhaps you are right ... that the Li content is
higher. I have asked for the analysis, and hope to have it soon. In
the meanwhile, I have recalculated/reformulated my glazes to have a
higher COE, and am in the process of testing them for fit.
I am curious to see what others have to say.
My best,
Paulette Carr
Paulette Carr Studio
Member/Potters Council
St. Louis, MO
On April 10, 2006 Gail Dapogny
It is very white, while our previous spodumene was light greyish. It
says that it is a product of Australia.
David Hewitt on tue 11 apr 06
Gail,
I don't know the answer to your question, but your thread interested me.
For what it is worth my spodumene is a very light greyish colour, but my
supply is from Bath Potters in the UK so may not be of interest to you.
I do not know its sieve or mesh figure but I do know its analysis
because Bath Potters give this information.
From what you say I presume that you have tried to glean from your
supplier exactly what he has supplied, but with limited success in that
he did not give you a full analysis. If he had and you also knew the
analysis of what you had previously used you would be far more able to
know what to do.
To my mind, this lack of precise information from pottery suppliers is
an all too frequent a problem and hence my interest in your thread. I
think that we should be far more demanding of our suppliers to provide
us with full data on what they are selling.
David
In message , Gail Dapogny writes
>Ron and others,
>Our guild has just received, in a shipment, "Spodumene Concentrate",
>75 micron. Apparently the lithium content is somewhat higher. It is
>very white, while our previous spodumene was light greyish. It says
>that it is a product of Australia.
>
>Should we be using this material differently from non-concentrate
>spodumene? Should we compensate in some way? Is the old non-
>concentrate spodumene still generally available?
>
>Any and all help will be greatly appreciated.
>
>thanks,
>Gail Dapogny in Ann Arbor
--
David Hewitt
Web:- http://www.dhpot.demon.co.uk
Mike Gordon on tue 11 apr 06
Gail,
The white granular Spodumene is "Gwalia", from Australia. I have a gray
colored Spodumene as well, it is powdery, and I don't know off hand who
mines it but I can find out if you want me to, just a phone call away.
The gray kind I got at Leslie's Ceramics in Berkeley, Ca. and it gave a
gray color to my white base at C/6 in a gas fired oxy atmosphere. The
Gwalia didn't change the base glaze at all which is white. They both
worked well at my temp, no difference. Mike Gordon, Walnut Creek, Ca.
On Apr 10, 2006, at 8:00 PM, Gail Dapogny wrote:
> Ron and others,
> Our guild has just received, in a shipment, "Spodumene Concentrate",
> 75 micron. Apparently the lithium content is somewhat higher. It is
> very white, while our previous spodumene was light greyish. It says
> that it is a product of Australia.
>
> Should we be using this material differently from non-concentrate
> spodumene? Should we compensate in some way? Is the old non-
> concentrate spodumene still generally available?
>
> Any and all help will be greatly appreciated.
>
> thanks,
> Gail Dapogny in Ann Arbor
>
> _______________________________________________________________________
> _______
> 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.
>
Sandy Miller on wed 12 apr 06
Hi Gail,
I am waiting for my kiln to drop so I can unload test tiles.
I have two tests of a Val Cushing Satin Matt. I mixed them
identically except for old spod vs new spod. I should unload
tonight and can let you know the difference.......or send
pictures if the difference is startling!
Stay Tuned............
Sandy Miller
www.sandymillerpottery.com
Ron Roy on wed 12 apr 06
Hi Gail,
Get an analysis for both - plug that into your calculator and you will be
able to compare the old and the new.
If you have analysis for both it's a snap - sub the old for the new in the
recipe and you'll see what you need to do to have the glaze come out the
same.
There are analysis for 3 different spods in my glaze workshop book by the
way and they are also in my MDT.
There was old spod around that had a lot of iron (Foote) but that was a
long time ago. Your grey is probably Tanko.
If you don't have the old analysis but know the name of the older stuff I
may be able to help - but get the numbers for the new stuff.
If you can't get the analysis for the old stuff test with the new spod and
adjust to get what you want - the Aussi stuff is just fine - and not much
iron.
RR
>Ron and others,
>Our guild has just received, in a shipment, "Spodumene Concentrate",
>75 micron. Apparently the lithium content is somewhat higher. It is
>very white, while our previous spodumene was light greyish. It says
>that it is a product of Australia.
>
>Should we be using this material differently from non-concentrate
>spodumene? Should we compensate in some way? Is the old non-
>concentrate spodumene still generally available?
>
>Any and all help will be greatly appreciated.
>
>thanks,
>Gail Dapogny in Ann Arbor
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Ivor and Olive Lewis on wed 12 apr 06
Dear Friends,
I hear you.
Have put out a feeler to see if I can get the Analysis for you.
Best regards,
Ivor.
ilene mahler on wed 12 apr 06
he was a big fan of duke Ellington and that's the story on the naming of the
glaze as I hear...Ilene in Conn
----- Original Message -----
From: "Sandy Miller"
To:
Sent: Wednesday, April 12, 2006 8:50 AM
Subject: spodumene
> Hi Gail,
> I am waiting for my kiln to drop so I can unload test tiles.
> I have two tests of a Val Cushing Satin Matt. I mixed them
> identically except for old spod vs new spod. I should unload
> tonight and can let you know the difference.......or send
> pictures if the difference is startling!
> Stay Tuned............
> Sandy Miller
> www.sandymillerpottery.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.
James and Sherron Bowen on sun 13 apr 08
What is "low melt Spodumene"?
Hank Murrow on sun 13 apr 08
On Apr 13, 2008, at 2:04 PM, James and Sherron Bowen wrote:
> What is "low melt Spodumene"?
Dear James;
Low Melt spodumene is a material based on amblygonite mineral ore. It
has a significant amount of phosphorus which contributes to the
firecolor in shinos. The bag has TANCO in big letters and is
processed in Canada, but I am unsure of the location of the mine.
Cheers, Hank
Steve Mills on mon 14 apr 08
Amblygonite is (or was) mined in Canada by the Tantalum Mining Company. I had reason to source it and that's what I found.
Steve
Bath
UK
Hank Murrow wrote:
On Apr 13, 2008, at 2:04 PM, James and Sherron Bowen wrote:
> What is "low melt Spodumene"?
Dear James;
Low Melt spodumene is a material based on amblygonite mineral ore. It
has a significant amount of phosphorus which contributes to the
firecolor in shinos. The bag has TANCO in big letters and is
processed in Canada, but I am unsure of the location of the mine.
Cheers, Hank
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Steve Mills on tue 15 apr 08
Dear Ivor Lewis,
W.G.Ball, Anchor Road, Longton, Stoke on Trent, Staffs, UK, sell Amblygonite; it is widely used in the manufacture of non-stick Saucepans.
Our mutual friend Brian Gartside included the material in some of his glaze tests on-line, so I assume he must have a source closer than the UK.
Best wishes
Steve
Bath
UK
Ivor and Olive Lewis wrote:
Dear Hank Murrow,
Hope you do not mind me chipping in on this one. Amblygonite is a mineral I have tried to get hold or for years. Managed to get one small mineral sample from the NT though there are reputed to be several billion tons under the red dessert sands north of Broken hill. But since it is considered worthless no one is mining at the present time.
Information I have tells me that Amblygonite is a Lithium Aluminium Fluoro-Phosphate with a fusion point at 800 deg C or slightly higher
In contrast, Spodumene is a Lithium Aluminium Silicate with a fusion point of about 1125 deg C.
Accepting your use of it a encourage colour in you Shino Glazes, the contrast between the two materials seems to indicate that Amblygonite would have limited use and not be a good substitute for high grade Spodumene or my favourite Australian Petalite..
Best regards,
Ivor Lewis.
Redhill,
South Australia.
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Hank Murrow on tue 15 apr 08
On Apr 14, 2008, at 11:20 PM, Ivor and Olive Lewis wrote:
>
> Information I have tells me that Amblygonite is a Lithium Aluminium
> Fluoro-Phosphate with a fusion point at 800 deg C or slightly
> higher. In contrast, Spodumene is a Lithium Aluminium Silicate with
> a fusion point of about 1125 deg C.
>
> Accepting your use of it a encourage colour in you Shino Glazes,
> the contrast between the two materials seems to indicate that
> Amblygonite would have limited use and not be a good substitute for
> high grade Spodumene or my favourite Australian Petalite..
Well, Ivor;
I sure would try some if it is available down under. I was very
surprised at the differences it allowed when subbing for the American
Foote minerals or Australian Spodumenes.
There are many brands of chocolate...... my preference is to try them
all.
Cheers, Hank
Ivor and Olive Lewis on tue 15 apr 08
Dear Hank Murrow,
Hope you do not mind me chipping in on this one. Amblygonite is a =
mineral I have tried to get hold or for years. Managed to get one small =
mineral sample from the NT though there are reputed to be several =
billion tons under the red dessert sands north of Broken hill. But since =
it is considered worthless no one is mining at the present time.
Information I have tells me that Amblygonite is a Lithium Aluminium =
Fluoro-Phosphate with a fusion point at 800 deg C or slightly higher
In contrast, Spodumene is a Lithium Aluminium Silicate with a fusion =
point of about 1125 deg C.
Accepting your use of it a encourage colour in you Shino Glazes, the =
contrast between the two materials seems to indicate that Amblygonite =
would have limited use and not be a good substitute for high grade =
Spodumene or my favourite Australian Petalite..
Best regards,=20
Ivor Lewis.
Redhill,
South Australia.
=20
Lee on wed 16 apr 08
On Tue, Apr 15, 2008 at 1:20 AM, Ivor and Olive Lewis
wrote:
> Accepting your use of it a encourage colour in you Shino Glazes, the contrast
>between the two materials seems to indicate that Amblygonite would
have limited
>use and not be a good substitute for high grade Spodumene or my favourite
>Australian Petalite..
Ivor,
I am not sure how accurate the data is you list. I just
did the Mino Shino from Britt's book and I used Alumina Oxide and Low
melt spodumene to cone 10 and got some very nice results. I will
put up photos tomorrow.
Folks have been using it around here in Minnesota for some time.
I think maybe the article in Studio Potter a while back about shinos
helped publicize its use.
I am trying to help Ian Currie come do a workshop in Mpls
when he tours the USA. Things are only in the beginning stages.
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Not everything that counts can be counted, and not everything that
can be counted counts." --(Sign hanging in Einstein's office at
Princeton)
Lee on wed 16 apr 08
Test photos from John Brit's Mino Shino in his glaze book. I used
Alumina Oxide and Low-melt spodumene
http://shinoglaze.blogspot.com/
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Not everything that counts can be counted, and not everything that
can be counted counts." --(Sign hanging in Einstein's office at
Princeton)
Ivor and Olive Lewis on thu 17 apr 08
Dear Steve Mills,=20
W. G. Ball are well known to us. We used their craft enamels for many =
years. But delivery charges can be expensive for materials I would not =
have a use for.
Best regards,
Ivor.
PS. My sample of clay is dewatering slowly.
You may wish to read the following illustrated research paper.=20
Ma, K & Pierre, A. C.=20
PACKING PATTERNS IN CLAY COLLOIDS. volume 1. Austceram 92. PP 315-320.
Or =
download...http://www.clays.org/journal/archive/volume%2047/47-4-522.pdf =
=20
Ivor and Olive Lewis on thu 17 apr 08
Dear Lee,=20
The information about the mineralogy of the two materials comes form my =
well thumbed copy of "Dana's Mineralogy".
I could have mentioned that Phosphate oxides are known to be glass =
formers so I had a look to see if there were any connections between =
Silicate and Phosphate systems. From information to hand I could find no =
direct connections. It is on record that some of the Phosphate glasses =
are water soluble. You will find information in Weyl and Chostner, Part =
1 Vol 2.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Lee on fri 18 apr 08
On Thu, Apr 17, 2008 at 1:33 AM, Ivor and Olive Lewis
wrote:
> Dear Lee,
>
> The information about the mineralogy of the two materials comes form my well thumbed copy of "Dana's Mineralogy".
>
The pot was fired to cone 10 in NCCs small soda kiln. The low-melt
spodmene in it worked very well, inspite of the data you shared.
See here:
http://shinoglaze.blogspot.com/:
http://shinoglaze.blogspot.com/
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Not everything that counts can be counted, and not everything that
can be counted counts." --(Sign hanging in Einstein's office at
Princeton)
Steve Mills on fri 18 apr 08
Dear Ivor Lewis,
I fully appreciate the cost factor, having experienced it in reverse from your continent.
Many thanks for the link.
Best regards
Steve Mills
Ivor and Olive Lewis wrote:
Dear Steve Mills,
W. G. Ball are well known to us. We used their craft enamels for many years. But delivery charges can be expensive for materials I would not have a use for.
Best regards,
Ivor.
PS. My sample of clay is dewatering slowly.
You may wish to read the following illustrated research paper.
Ma, K & Pierre, A. C.
PACKING PATTERNS IN CLAY COLLOIDS. volume 1. Austceram 92. PP 315-320.
Or download...http://www.clays.org/journal/archive/volume%2047/47-4-522.pdf
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Lee on sat 19 apr 08
Spodumene - Ceramic grade (55#bag) $0.93 $46.50
Spodumene - Low Melt (55# bag) $0.85 $42.50
Here Low Melt is less expensive than Ceramic grade. 85cents a lb for
55lbs bag verses 93cents a pound for 55lbs.
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Not everything that counts can be counted, and not everything that
can be counted counts." --(Sign hanging in Einstein's office at
Princeton)
Ivor and Olive Lewis on sat 19 apr 08
Dear Lee ,
Not sure what you mean by "Low Melt".
<spodumene in it worked very well, inspite of the data you shared. >>
Given the melting point of about 1100 deg C I am sure your material =
labelled "Low Melt Spodumene" gives excellent results when fired to cone =
10 (1300 deg C).Best regards,
Ivor
Lee on sat 19 apr 08
On Sat, Apr 19, 2008 at 1:20 AM, Ivor and Olive Lewis
wrote:
> Dear Lee ,
>
> Not sure what you mean by "Low Melt".
You can see here Amblygonite here:
http://shinoglaze.blogspot.com/
"Not everything that counts can be counted, and not everything that
can be counted counts." --(Sign hanging in Einstein's office at
Princeton)
James and Sherron Bowen on sun 20 apr 08
I am still curious as to when I could substitute the low melt for the
ceramic grade and why I would want to.
Jim
----- Original Message -----
From: "Lee"
To:
Sent: Saturday, April 19, 2008 9:12 AM
Subject: Re: Spodumene
> Spodumene - Ceramic grade (55#bag) $0.93 $46.50
> Spodumene - Low Melt (55# bag) $0.85 $42.50
Lee on sun 20 apr 08
On Sun, Apr 20, 2008 at 11:35 AM, James and Sherron Bowen
wrote:
> I am still curious as to when I could substitute the low melt for the
> ceramic grade and why I would want to.
Did you look at the photo? *sigh!* That says it all to me.
There is no clay in that Mino shino, only alumina oxide. There is
also no soda ash and you can guess what that means. The low melt
helps soften the alumina. If you compare my photo to John Britt's
photo using ceramic grade, you'll see that his tests requires a higher
temp or longer firing.
I think if you are happy with what you are using, there
isn't no reason to change it. For me, it really enhances the shino
type glazes. It crawls and pits nicely on the trimmed areas but is
smooth and without blemish on the hakeme slip on the inside. Best of
both worlds.
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
"Not everything that counts can be counted, and not everything that
can be counted counts." --(Sign hanging in Einstein's office at
Princeton)
Hank Murrow on sun 20 apr 08
On Apr 20, 2008, at 9:35 AM, James and Sherron Bowen wrote:
> I am still curious as to when I could substitute the low melt for the
> ceramic grade and why I would want to.
Dear James;
If you would want some phosphorus in your glaze, using Low Melt will
bring it in. Phosphorus was what helped the iron in Shaners Red to be
red. Phosphorus also helps shinos to be red.
Cheers, Hank
James and Sherron Bowen on sun 20 apr 08
Thanks Hank. I knew I could rely on you for the answer.
JB
----- Original Message -----
From: "Hank Murrow"
To:
Sent: Sunday, April 20, 2008 1:30 PM
Subject: Re: Spodumene
> On Apr 20, 2008, at 9:35 AM, James and Sherron Bowen wrote:
>
>> I am still curious as to when I could substitute the low melt for the
>> ceramic grade and why I would want to.
>
> Dear James;
>
> If you would want some phosphorus in your glaze, using Low Melt will
> bring it in. Phosphorus was what helped the iron in Shaners Red to be
> red. Phosphorus also helps shinos to be red.
>
> Cheers, Hank
>
> ______________________________________________________________________________
> Clayart members may send postings to: clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post messages, change your
> subscription settings or unsubscribe/leave the list here:
> http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots2@visi.com
>
>
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