Patty Rios on tue 23 oct 07
What do you do when you get down to the last 4 or 5 inches of the glaze bucket? I am sure the original glaze recipe differs so much from what I have sitting on the bottoms of the buckets. Just toss them out? or can I add something? The colors are just fine. Its just the pinholes that are suddenly appearing. I know it could be anything since this is an open studio. We are using Mastering Cone 6 glazes (great book). The Caribbean and the Majolica are the worst but waterfall brown, bone, smash-it blue, and licorice are holding up. Even though they probably are all contaminated by now.
So what would you do?
Taylor Hendrix on tue 23 oct 07
I would make up a new batch and put it aside. I would then add a bit
of water to the old batch and mix with a paddle so as not to stir in
air bubbles.
This is just a guess, but you might have aired up the old glaze
because there was so little in the buckets. Bubbles and thickening
glaze (does that over time with lots of dipping) can cause later
pinholes once the glaze melts. Run pieces with coatings of the new
batch and the old batch side by side. If they look the same, no
pinholes, just combine the two batches and you waste nothing.
Taylor, in Rockport.
On 10/23/07, Patty Rios wrote:
> What do you do when you get down to the last 4 or 5 inches of the glaze bucket? I am sure the original glaze recipe differs so much from what I have sitting on the bottoms of the buckets. Just toss them out? or can I add something? The colors are just fine. Its just the pinholes that are suddenly appearing. I know it could be anything since this is an open studio. We are using Mastering Cone 6 glazes (great book). The Caribbean and the Majolica are the worst but waterfall brown, bone, smash-it blue, and licorice are holding up. Even though they probably are all contaminated by now.
> So what would you do?
Bill Merrill on wed 24 oct 07
Taylor,
If you totally dry out a glaze and then reconstitute the glaze you won't
have air bubble problems. Many times pin holing can come from organics
in the glaze (ball clay) and firing the glaze too fast. When I mix my
glazes I usually mix 15,000 gram batches and mix it with an electric
drill. There are always bubbles in the glaze. I pick up the bucket a
few inches off the ground and tap it on the floor numerous times. The
bubbles come to the top of the glaze. Bubbles form more in a shino type
glaze than any other type of glaze. I always add some water to the
bucket first and then add in the dry mixed glaze until I need more water
and dry ingredients. I use a heavy liquid hydrometer to get the same
consistency from each glaze I use.=20
If you don't want runs from the dipping process add one cup of muratic
acid to 10,000 grams of wet glaze. The glaze is thicker and you have to
get used to using it. I find the glaze can look thicker than normal on
a pot, but will become thinner as the glaze dries. Victor Babu makes
90,000 grams of glaze and dips is large platters in special made
containers so he can glaze his platters in one operation, (the
background glaze on his platters)
Bill billm@pcadmin.ctc.edu
=20
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Taylor
Hendrix
Sent: Tuesday, October 23, 2007 5:03 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: pin holes and craters
I would make up a new batch and put it aside. I would then add a bit
of water to the old batch and mix with a paddle so as not to stir in
air bubbles.
This is just a guess, but you might have aired up the old glaze
because there was so little in the buckets. Bubbles and thickening
glaze (does that over time with lots of dipping) can cause later
pinholes once the glaze melts. Run pieces with coatings of the new
batch and the old batch side by side. If they look the same, no
pinholes, just combine the two batches and you waste nothing.
Taylor, in Rockport.
On 10/23/07, Patty Rios wrote:
> What do you do when you get down to the last 4 or 5 inches of the
glaze bucket? I am sure the original glaze recipe differs so much from
what I have sitting on the bottoms of the buckets. Just toss them out?
or can I add something? The colors are just fine. Its just the pinholes
that are suddenly appearing. I know it could be anything since this is
an open studio. We are using Mastering Cone 6 glazes (great book). The
Caribbean and the Majolica are the worst but waterfall brown, bone,
smash-it blue, and licorice are holding up. Even though they probably
are all contaminated by now.
> So what would you do?
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Taylor Hendrix on wed 24 oct 07
Could be, Bill. Patty seems to think the pinholling is something "new"
which makes me think the low volume plus thicker glaze (perhaps) has
entrained air when she glazes. These bubbles will not move out of the
glaze if I understood our very own Dave the Super Freak's talk at
NCECA this year.
Patty, still too many things could be the problem. Have you had a
chance to make up the new batch yet?
Tay Tay
On 10/24/07, Bill Merrill wrote:
> Taylor,
>
> If you totally dry out a glaze and then reconstitute the glaze you won't
> have air bubble problems. Many times pin holing can come from organics
> in the glaze (ball clay) and firing the glaze too fast. When I mix my
> glazes I usually mix 15,000 gram batches and mix it with an electric
> drill. There are always bubbles in the glaze. ...
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