Charles Moore on sat 20 sep 03
Nancy,
I have tried the same glazes without the problems you report. Is it
possible that some of the coloring oxides are causing the problem? Try
sieving through 80 mesh three times.
I have found that the "Licorice" glaze tends to go brownish on the outside.
Ron Roy recommended adding 1/2 % cobalt carbonate.
Charles Moore
Sacramento
----- Original Message -----
From: "The Hallquist's"
Subject: NEW SUBSCRIBER
I am new to this list and am in need of some help. I have been mixing my
own glazes for about 2 years with very limited success. Recently I
purchased Ron Roy's book and have mixed up some of these glazes. I am
having a problem with the black. It seems that it is full of rough spots.
I would say some pinholes and some spots that look like pinholes but you can
actually feel them. Is the glaze too thin? All my other glazes I mix quite
a bit thinner than this one and don't get the same problem. I bisque to
Cone 04. Any help would be greatly appreciated. Also, I have tried Glossy
base glaze 1 with many different colorants. When I use just the base glaze
on it's own it is a nice smooth glaze but with added colour there are many
pinholes. I find that with both the black and this glaze the problem is
more on the inside of a bowl and not so much on the vertical surfaces. Any
suggestions would be appreciated.
Nancy
____________________________________________________________________________
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The Hallquist's on sun 21 sep 03
Thanks for the suggestion. Now that I think of it I think I am using a 60
mesh. Don't have a 80 mesh, could I use 100 mesh, I have one of those? I
was thinking this could be it but didn't know what to do, so thank you
again.
Nancy
----- Original Message -----
From: "Charles Moore"
To:
Sent: Saturday, September 20, 2003 10:14 AM
Subject: Glaze pinholes
Nancy,
> >
> I have tried the same glazes without the problems you report. Is it
> possible that some of the coloring oxides are causing the problem? Try
> sieving through 80 mesh three times.
>
> I have found that the "Licorice" glaze tends to go brownish on the
outside.
> Ron Roy recommended adding 1/2 % cobalt carbonate.
>
> Charles Moore
> Sacramento
>
> ----- Original Message -----
> From: "The Hallquist's"
> Subject: NEW SUBSCRIBER
>
>
> I am new to this list and am in need of some help. I have been mixing my
> own glazes for about 2 years with very limited success. Recently I
> purchased Ron Roy's book and have mixed up some of these glazes. I am
> having a problem with the black. It seems that it is full of rough spots.
> I would say some pinholes and some spots that look like pinholes but you
can
> actually feel them. Is the glaze too thin? All my other glazes I mix
quite
> a bit thinner than this one and don't get the same problem. I bisque to
> Cone 04. Any help would be greatly appreciated. Also, I have tried
Glossy
> base glaze 1 with many different colorants. When I use just the base
glaze
> on it's own it is a nice smooth glaze but with added colour there are many
> pinholes. I find that with both the black and this glaze the problem is
> more on the inside of a bowl and not so much on the vertical surfaces.
Any
> suggestions would be appreciated.
> Nancy
>
>
____________________________________________________________________________
> __
> 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.
>
>
____________________________________________________________________________
__
> 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.
>
The Hallquist's on sun 21 sep 03
I know what you mean about the pinholes right after glazing and I have not
seen this with this glaze. I always sponge off my bisqued pots with a bit
of water to get rid of any dust.
Nancy
----- Original Message -----
From: "Lee Love"
To:
Sent: Sunday, September 21, 2003 4:32 PM
Subject: Re: Glaze pinholes
> ----- Original Message -----
> From: "John Baymore"
>
> > What is the claybody you are using? At what temperature do you bisque?
> >Are you using witness cones on the shelves of the kiln or are you relying
> >on the controller or a kiln sitter to determine "endpoint"?
>
>
> To add to John's variables: Do the pinholes appear right after you
> glaze? Where I studied, we bisqued to a pretty low temperature.
Also,
> inlay decoration was used and the scraping left dust on the ware after
> bisquing. We cleaned the work with a duster and then we damp sponged
the
> ware. If we didn't sponge, or didn't sponge correctly, you would see
> pinholes right after glazing.
>
> These can be rubbed out if they are small or filled with a brush.
>
> --
> Lee In Mashiko, Japan Lee@Mashiko.org
>
> To Subscribe to my Email Lists send blank email to:
> Wood Firing: WoodKiln-subscribe@yahoogroups.com
> Akita Dog Photos: akita-g-subscribe@yahoogroups.com
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>
>
____________________________________________________________________________
__
> 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.
>
The Hallquist's on sun 21 sep 03
Thank you for your response. In answer to your questions. I have been
using a 60 mesh sieve. Another reader advised me to use 80 and I have
already sieved the black through my 100 mesh and am testing it tomorrow. I
am using cone 5 Bmix. I bisque to cone 04 just using the cone fire mode on
the computerized kiln and soak it for 40 minutes. I use witness cones
always. But I do rely on the computer to shut off the kiln. I am always
there to check it is shut off and I have not had a problem yet. The cones
are always right on. My firing schedule is 100 f per hour to 250 f and then
225 f to 2100 then hold 10 minutes then 65 f per hour to 2185 then soak for
20 minutes then cool 300 f per hour down to 1500. Seems to work okay for
other glazes I use. I should mention that I also mixed up John and Ron's
Raw Sienna and have to say not a single pinhole. The surface is flawless.
I am baffled. I know that it is something that I am doing wrong but
what???? Thank you for your help.
Nancy
----- Original Message -----
From: "John Baymore"
To:
Sent: Sunday, September 21, 2003 9:52 AM
Subject: Glaze pinholes
I am having a problem with the black. It seems that it is full of rough
spots.
I would say some pinholes and some spots that look like pinholes but you
can
actually feel them. Is the glaze too thin? All my other glazes I mix
quite
a bit thinner than this one and don't get the same problem. I bisque to
Cone 04. Any help would be greatly appreciated. Also, I have tried Glossy
base glaze 1 with many different colorants. When I use just the base glaze
on it's own it is a nice smooth glaze but with added colour there are many
pinholes.
Nancy,
Hi.
Any glaze does not exist alone. The glaze mixture itself is only ....let's
say maybe 1/4 of the "end result" picture.
The other 3/4 include the application of the glaze coating, the clay body
the glaze coating is applied upon, ansd lastly the exact firing cycle that
the glaze and clay are exposed to.
I am sure that you have already seen that the glaze thickness can vary the
glaze color/surface/opacity and so on. The clay body itself can also alter
the finished
results. And the firing cycle (both for the bisque and for the finish
fire) can impart dramatic differences.
Knowing Ron and John
...... I'd say that the solutions to your issues probably lie in the later
3/4 of the equation . So more information about those aspects of how
the glaze mixture is handled would give those of us who tend to be "tech
weenies" reading clayart a lot more "ammunition in the gun", so to speak.
A couple of quick questions right off the top that relates to glaze
preparation.......... what is the mesh of the seive that you are running
the glaze thru when you prepare it?
What is the claybody you are using? At what temperature do you bisque?
Are you using witness cones on the shelves of the kiln or are you relying
on the controller or a kiln sitter to determine "endpoint"?
best,
......................john
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086-5812 USA
JBaymore@compuserve.com
http://www.JohnBaymore.com
603-654-2752 (studio)
800-900-1110 (studio)
____________________________________________________________________________
__
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.
John Baymore on sun 21 sep 03
I am having a problem with the black. It seems that it is full of rough
spots.
I would say some pinholes and some spots that look like pinholes but you
can
actually feel them. Is the glaze too thin? All my other glazes I mix
quite
a bit thinner than this one and don't get the same problem. I bisque to
Cone 04. Any help would be greatly appreciated. Also, I have tried Glos=
sy
base glaze 1 with many different colorants. When I use just the base gla=
ze
on it's own it is a nice smooth glaze but with added colour there are man=
y
pinholes.
Nancy,
Hi.
Any glaze does not exist alone. The glaze mixture itself is only ....let=
's
say maybe 1/4 of the "end result" picture.
The other 3/4 include the application of the glaze coating, the clay body=
the glaze coating is applied upon, ansd lastly the exact firing cycle tha=
t
the glaze and clay are exposed to.
I am sure that you have already seen that the glaze thickness can vary th=
e
glaze color/surface/opacity and so on. The clay body itself can also alt=
er
the finished =
results. And the firing cycle (both for the bisque and for the finish
fire) can impart dramatic differences. =
Knowing Ron and John
...... I'd say that the solutions to your issues probably lie in the late=
r
3/4 of the equation . So more information about those aspects of how
the glaze mixture is handled would give those of us who tend to be "tech
weenies" reading clayart a lot more "ammunition in the gun", so to speak.=
=
A couple of quick questions right off the top that relates to glaze
preparation.......... what is the mesh of the seive that you are running
the glaze thru when you prepare it?
What is the claybody you are using? At what temperature do you bisque?=
=
Are you using witness cones on the shelves of the kiln or are you relying=
on the controller or a kiln sitter to determine "endpoint"? =
best,
......................john
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086-5812 USA
JBaymore@compuserve.com
http://www.JohnBaymore.com
603-654-2752 (studio)
800-900-1110 (studio) =
SusanRaku@AOL.COM on mon 22 sep 03
In a message dated 9/22/2003 8:52:49 PM Eastern Daylight Time,
ronroy@TOTAL.NET writes:
> If the pin holes remain the same or get worse when refired - then it is a
> bisque firing problem or the clay is simply over fluxed.
>
>
Does this mean that the bisque temp should be higher or lower and why ?
Thanks.
Susan
Lee Love on mon 22 sep 03
----- Original Message -----
From: "John Baymore"
> What is the claybody you are using? At what temperature do you bisque?
>Are you using witness cones on the shelves of the kiln or are you relying
>on the controller or a kiln sitter to determine "endpoint"?
To add to John's variables: Do the pinholes appear right after you
glaze? Where I studied, we bisqued to a pretty low temperature. Also,
inlay decoration was used and the scraping left dust on the ware after
bisquing. We cleaned the work with a duster and then we damp sponged the
ware. If we didn't sponge, or didn't sponge correctly, you would see
pinholes right after glazing.
These can be rubbed out if they are small or filled with a brush.
--
Lee In Mashiko, Japan Lee@Mashiko.org
To Subscribe to my Email Lists send blank email to:
Wood Firing: WoodKiln-subscribe@yahoogroups.com
Akita Dog Photos: akita-g-subscribe@yahoogroups.com
FolkCraft: mingei-subscribe@yahoogroups.com
Zen Practice: E-zendo-subscribe@yahoogroups.com
Ron Roy on mon 22 sep 03
The pits in raw glaze you see just after glazing are not related to pin
holes in the fired glaze - unless the glaze is just underfired.
Pin holes are due to gases coming through from the clay or the glaze bubbling.
Some times all that is necessary is a soak (hold) at the end of the firing
to give the craters a chance to heal over.
If the glaze is too "stiff" is can be adjusted from more flow to help heal them.
If the pin holes remain the same or get worse when refired - then it is a
bisque firing problem or the clay is simply over fluxed.
RR
>I know what you mean about the pinholes right after glazing and I have not
>seen this with this glaze. I always sponge off my bisqued pots with a bit
>of water to get rid of any dust.
>Nancy
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
The Hallquist's on tue 23 sep 03
I am replying to all who have sent me suggestions regarding the pinhole
issue with the black glaze of Ron and John's. I want to thank everyone for
there help and update you on my findings.
I sieved the glaze through a 100 mesh sieve twice and then fired one pot on
exactly the same firing schedule. Results were slightly better but the
pinholes are still there mostly on the horizontal. Still feels rough to
the touch. Ron, I have taken out some water from the glaze, but didn't know
how much to take out so I will do it in increments. I will fire the kiln
again tomorrow with another test and let you know. I will refire a piece as
well and see what happens.
Thank you again
Nancy
----- Original Message -----
From: "Ron Roy"
To:
Sent: Monday, September 22, 2003 6:06 PM
Subject: Re: Glaze pinholes
> The pits in raw glaze you see just after glazing are not related to pin
> holes in the fired glaze - unless the glaze is just underfired.
>
> Pin holes are due to gases coming through from the clay or the glaze
bubbling.
>
> Some times all that is necessary is a soak (hold) at the end of the firing
> to give the craters a chance to heal over.
>
> If the glaze is too "stiff" is can be adjusted from more flow to help heal
them.
>
> If the pin holes remain the same or get worse when refired - then it is a
> bisque firing problem or the clay is simply over fluxed.
>
> RR
>
> >I know what you mean about the pinholes right after glazing and I have
not
> >seen this with this glaze. I always sponge off my bisqued pots with a
bit
> >of water to get rid of any dust.
> >Nancy
>
> Ron Roy
> RR#4
> 15084 Little Lake Road
> Brighton, Ontario
> Canada
> K0K 1H0
> Phone: 613-475-9544
> Fax: 613-475-3513
>
>
____________________________________________________________________________
__
> 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.
>
The Hallquist's on sat 27 sep 03
Just wanted to update everyone on my pinhole dilema. I tried sieving
through the 100 mesh with a bit of an improvement. But, I removed a fair
amount of water from the glaze as Ron Roy suggested and the difference is
dramatic. There are still a few pinholes but very tiny and not as many.
And you certainly can't feel them anymore. I will remove some more water
and see if I can totally get rid of them. Also, Ron, I refired one of the
badly pinholed plates and the pinholes improved. Not gone but quite an
improvement. I can't tell you how much I appreciate the advice, you have
saved me a lot of heartache. Also, thanks to John Baymore for your words
regarding the glaze mixture only being 1/4 of the equation. It somehow
really clarified things for me.
Nancy
Susan Setley on sun 28 sep 03
In a message dated 9/28/03 12:32:47 AM, missionhallquist@TELUS.NET writes:
<< Just wanted to update everyone on my pinhole dilema. I tried sieving
through the 100 mesh with a bit of an improvement. But, I removed a fair
amount of water from the glaze as Ron Roy suggested and the difference is
dramatic. There are still a few pinholes but very tiny and not as many.
And you certainly can't feel them anymore. >>
This is fascinating. I have had a problem with pinholes and a shino recently.
Someone suggested that i slightly dampen the surface before glazing, and
someone else said to thin the glaze a little. Normally this glaze is a good fit
with the clay body so I don't think that's an issue, but for those who really
understand that stuff (I don't -- yet) -- I'm using Vegas buff, which is a very
smooth, plastic cone 10 stoneware that apparently has a lot of organic matter
in it, as it is dark (not rusty dark) in the bag but nearly white with only
the slightest cast of color when bisqued.
Ron Roy on tue 30 sep 03
Hi Susan,
Pin holes happen for several different reasons.
All glazes go through bubbling stages - if the kiln is stopped during one
of these episodes some bubbles don't have a chance to heal over. This is
especially true if the glaze is "stiff" (has a high surface tension or
viscosity) - shino glazes are like that - lots of alumina which is at the
top (high) of the viscosity and surface tension list of the oxides we use.
It is not uncommon for shino glazes to have pinholes.
If this is the reason it is happening you can add more flux or remove some
alumina, or fire higher, or cool slower.
If the pin holes are caused by the clay outgassing - especially with iron
bearing clay bodies - the cure may lie in a cleaner bisque firing. If the
clay is being over fired the same thing will happen - you will know if this
is the cause when your refire and the problem gets worse.
The reason a thicker glaze coat helps with some glazes is - there is more
glaze to flow in and heal the pin holes.
Not all the reasons but what I think may be the problem.
RR
>This is fascinating. I have had a problem with pinholes and a shino recently.
>Someone suggested that i slightly dampen the surface before glazing, and
>someone else said to thin the glaze a little. Normally this glaze is a good fit
>with the clay body so I don't think that's an issue, but for those who really
>understand that stuff (I don't -- yet) -- I'm using Vegas buff, which is a very
>smooth, plastic cone 10 stoneware that apparently has a lot of organic matter
>in it, as it is dark (not rusty dark) in the bag but nearly white with only
>the slightest cast of color when bisqued.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Susan Setley on tue 30 sep 03
In a message dated 9/30/03 1:40:47 PM, ronroy@TOTAL.NET writes:
<< Hi Susan,
Pin holes happen for several different reasons.
All glazes go through bubbling stages - if the kiln is stopped during one
of these episodes some bubbles don't have a chance to heal over. >>
RonRoy, thanks for your response!
I don't think the kiln has ever been stopped, but the bubbles formed as the
glaze was applied. It wasn't a firing occurence.
The glaze bubbled and formed many tiny craters as it was dipped into the
glaze. Does that make sense now?
Ron Roy on thu 2 oct 03
Hi Susan,
I meant stopped at the end - shut off.
I have a shino of my own and if I stir it really hard it gets frothy - I
use this as a decorative variation,
If the holes are still there at the end of the firing and you don't like em
- stir so there are no bubbles and/or rub em out before you fire em.
Best regards - RR
>Pin holes happen for several different reasons.
>
>All glazes go through bubbling stages - if the kiln is stopped during one
>of these episodes some bubbles don't have a chance to heal over. >>
>
>RonRoy, thanks for your response!
>
>I don't think the kiln has ever been stopped, but the bubbles formed as the
>glaze was applied. It wasn't a firing occurence.
>
>The glaze bubbled and formed many tiny craters as it was dipped into the
>glaze. Does that make sense now?
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Mary White on wed 26 nov 03
Glaze Gurus--
I just unloaded my kiln this morning and a few items had pinholes,
not a whole cluster but just the odd tiny hole here and there. I read
in Ron & John that this is caused by gas escaping, often because the
bisque was underfired. My bisque was fired to 06, which should be
okay, but it's ^10 clay that was fired to ^6. Could that cause a
situation similar to underfiring a ^6 clay?
Mary
--
Mary White
HARBOUR PUBLISHING
Box 219
Madeira Park, BC
V0N 2H0
------------------
Publishers of the Encyclopedia of British Columbia.
For current news and complete book & author information, visit our
website, http://www.harbourpublishing.com.
Ron Roy on thu 27 nov 03
Hi Mary,
It is true - especially with iron bearing clays - that making sure the
bisque firings should be "clean."
I don't think this is the problem you have however - in the above case it
is over firing of the body that is the problem - if you are using a cone 10
clay at cone 6 it is most unlikely to happen.
What is happening is - the melt of the clay has a strong effect on glazes
melt. If you fire stoneware and porcelain in the same kiln with the same
glaze you will see this.
What happened to you is probably just the clay holding back the melt of the
glaze - you need to fire it higher or soak longer till the glaze smooth
out.
If you put cones on each level (bottom and each shelf) - you will probably
find where your kiln is not getting as hot - I would guess that is were the
pots with the pinholes were.
Soaking not only helps the pinholes to heal over but helps (a lot) to even
out the temperature in the kiln - start your soak just as cone 6 starts to
bend so you don't over fire during the soaking time.
Better still - use a cone 6 clay - the cone 10 clay is going to absorb
water during use and make it unsuitable for microwaving, it will stain, and
water mark wood - and eventually look and smell bad.
RR
>I just unloaded my kiln this morning and a few items had pinholes,
>not a whole cluster but just the odd tiny hole here and there. I read
>in Ron & John that this is caused by gas escaping, often because the
>bisque was underfired. My bisque was fired to 06, which should be
>okay, but it's ^10 clay that was fired to ^6. Could that cause a
>situation similar to underfiring a ^6 clay?
>
>Mary
>Mary White
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Mary White on mon 1 dec 03
Hi Ron, I was hoping to hear from you.
>
>What happened to you is probably just the clay holding back the melt of the
>glaze - you need to fire it higher or soak longer till the glaze smooth
>out.
I soaked for 20 minutes, should I have gone longer? After that I
turned the kiln off until it got to 1850 and turned it back to medium
until 1400, then off again. I don't have a controller.
>
>If you put cones on each level (bottom and each shelf) - you will probably
>find where your kiln is not getting as hot - I would guess that is were the
>pots with the pinholes were.
I did have cone packs on all three levels and found top and bottom
(where the pinholed pots were) are not as hot as the middle, where ^7
was nearly down 45 degrees. There were a bunch of mugs in the middle
glazed with Caribbean green that came out glossy blue, colour much
like Variegated Slate but variegated with a kind of pea-soup green.
I'm assuming this is overfiring.
>
>Better still - use a cone 6 clay - the cone 10 clay is going to absorb
>water during use and make it unsuitable for microwaving, it will stain, and
>water mark wood - and eventually look and smell bad.
I have noticed the mugs are moist on the bottom when full of hot
coffee, much like my earthenware mugs from Portugal. Good news is
I've just got a shipment of ^6 B-mix so I'll keep trying.
Thanks for your help,
Mary
--
Mary White
HARBOUR PUBLISHING
Box 219
Madeira Park, BC
V0N 2H0
------------------
Publishers of the Encyclopedia of British Columbia.
For current news and complete book & author information, visit our
website, http://www.harbourpublishing.com.
John Hesselberth on mon 1 dec 03
Hi Mary,
When Caribbean Sea Green comes out blue it is usually because the
rutile level is not high enough. This is probably the most common
question we get regarding the glazes in the book. People wonder if it
is a typo and should have been copper carbonate instead of cobalt
carbonate. No typ0--you really do get the color from cobalt, but the
rutile has to be high enough. Rutiles from different suppliers vary
enough that you may have to go to 8 or even 10 % to get the color shift
from blue to green on this glaze. It sounds like you are right on the
edge of the shift--you may only need 7 or 8%.
Regards,
John
On Monday, December 1, 2003, at 05:14 PM, Mary White wrote:
> Caribbean green that came out glossy blue, colour much
> like Variegated Slate but variegated with a kind of pea-soup green.
> I'm assuming this is overfiring.
http://www.frogpondpottery.com
http://www.masteringglazes.com
Ron Roy on fri 5 dec 03
Hi Mary,
If the body is refractory at cone 6 it will take a lot of soaking to make
up for that - and the clay will still leak - you need to do an absorption
yest on the clay at cone 6 for me to answer the question properly - let me
know if you want instructions on how to do that.
Sounds like you need to fire higher to get the glazes to melt properly -
slow firing will help even out your kiln and the soaking will help too.
Let me know if you need more on this.
RR
>Hi Ron, I was hoping to hear from you.
>
>>
>>What happened to you is probably just the clay holding back the melt of the
>>glaze - you need to fire it higher or soak longer till the glaze smooth
>>out.
>
>I soaked for 20 minutes, should I have gone longer? After that I
>turned the kiln off until it got to 1850 and turned it back to medium
>until 1400, then off again. I don't have a controller.
>
>>
>>If you put cones on each level (bottom and each shelf) - you will probably
>>find where your kiln is not getting as hot - I would guess that is were the
>>pots with the pinholes were.
>
>I did have cone packs on all three levels and found top and bottom
>(where the pinholed pots were) are not as hot as the middle, where ^7
>was nearly down 45 degrees. There were a bunch of mugs in the middle
>glazed with Caribbean green that came out glossy blue, colour much
>like Variegated Slate but variegated with a kind of pea-soup green.
>I'm assuming this is overfiring.
>>
>>Better still - use a cone 6 clay - the cone 10 clay is going to absorb
>>water during use and make it unsuitable for microwaving, it will stain, and
>>water mark wood - and eventually look and smell bad.
>
>I have noticed the mugs are moist on the bottom when full of hot
>coffee, much like my earthenware mugs from Portugal. Good news is
>I've just got a shipment of ^6 B-mix so I'll keep trying.
>
>Thanks for your help,
>
>Mary
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
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