single firing ash glazes

Does anyone out there single fire ash glazes? As far as getting the
slop to stay on the pot there are no problems, the problem is that as,
in my experience, ash glazes are nicest when applied nice and thick,
the glaze water soaks onto the pot wall and causes cracking. I'm
guessing that I could get round the problem by glazing at leatherhard,
but the pots are all dry now, as I was a bit late with working out my
recipies. I'm sure that if I watered the slop down and applied two or
three coats, waiting for the pots to dry completely between coats this
would get round the problem, but this obviously amounts to the
equivalent of glazing several times the amount of pots that I acually
have.
Any tips or hints for a young potter would be warmly welcome.

Thanks,

Alistair.

It seems to me that you need to deflocculate your glazes so that they
contain as little water as possible, and then apply them in stages
over time -- in other words, first, the insides -- then let them dry
Second, the rims -- let them. Third, the outsides, etc. If they get
water in increments perhaps they'll be less inclined to crack.

Ceramics Monthly for December, 1994, has an article by Richard Aerni
on "Single-Fired Ash Glazing." In it, he mentions that he sprays his
ash glazes in stages onto raw pots, but doesn't say at what stage of
dryness. He also says he prepares just enough glazes for the days
work because his unwashed glazes flocculate over time.

Good luck -- Let us know how you solve this problem.

Marco



On 10 Apr 2005 02:46:19 -0700, (ali) wrote:

Does anyone out there single fire ash glazes? As far as getting the
slop to stay on the pot there are no problems, the problem is that as,
in my experience, ash glazes are nicest when applied nice and thick,
the glaze water soaks onto the pot wall and causes cracking. I'm
guessing that I could get round the problem by glazing at leatherhard,
but the pots are all dry now, as I was a bit late with working out my
recipies. I'm sure that if I watered the slop down and applied two or
three coats, waiting for the pots to dry completely between coats this
would get round the problem, but this obviously amounts to the
equivalent of glazing several times the amount of pots that I acually
have.
Any tips or hints for a young potter would be warmly welcome.

Thanks,

Alistair.

i guess in a weird way you could put wood in your bowls to burn, ash,
and glaze in the same fire? or pile on raw ash with no water? or what
about mixing ash in Elmer's Glue (that white water based glue) and glue
the glaze to your pot?

i never tried any of this, but their must be a liquid carrier that
could be used to add the ash to the pot without watering down the pot?

i mess around with "black fired" pots where i mix graphite with salad
oil & apply this to bisque pots.

possibly a mix of salad oil & ash would head in your direction?

see ya

steve

On 10 Apr 2005 11:00:28 -0700, "steve "
wrote:

i guess in a weird way you could put wood in your bowls to burn, ash,
and glaze in the same fire? or pile on raw ash with no water? or what
about mixing ash in Elmer's Glue (that white water based glue) and glue
the glaze to your pot?

i never tried any of this, but their must be a liquid carrier that
could be used to add the ash to the pot without watering down the pot?

i mess around with "black fired" pots where i mix graphite with salad
oil & apply this to bisque pots.

possibly a mix of salad oil & ash would head in your direction?


I've mixed up "regular" (non-ash) glazes using canola oil
instead of water for just this purpose. I wanted to single-fire
some pieces that were bone dry, and may usual water-based
glazes caused the pieces to crack from water re-absorption,
even on a single application to just the inside of the piece.
The oil-based glaze did the trick, but it was a problem to
handle the pieces to get them into the kiln. The oil vanished
into the interior of the clay, leaving the glaze as a powdery
residue on the surface, sort of like the scales on butterfly
wings... the slightest touch would mar it.

Perhaps straight ash in oil wouldn't have this problem.

I've been thinking of other bases instead of this oil, which
might work better, but haven't tried any yet. If I were
going to use this regularly, and not just as an experiment
or "in a pinch", I'd want to find something that not only
worked, but was inexpensive and readily available, and
that didn't release noxious fumes when burning out
in the kiln. There is also the issue of flammability during
the application, if you try other organic sovents, etc.
For example, gasoline might work, but I'm sure not going
to try it! I'll probably try concentrated rubbing alcohol
when I next get into a pinch, but it's too expensive for
everyday use even if it works perfectly.

Anyone have any other suggestions for cheap non-aqueous
bases to try?

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com

In article .com,
steve wrote:

i mess around with "black fired" pots where i mix graphite with salad
oil & apply this to bisque pots.

steve

This sounds interesting--what does it look like? How do you fire it,
is it a pit firing type of thing? What kind of mix is it, and is it
painted on or do you dip the pots?

Deb R.

i use about 1 quart of salad oil with 1 teaspoon of graphite. i apply
to bisque pots.

the pots are placed in a metal can surounded with sawdust. i close the
can, and put a brick on the top. in the kiln i fire to about "can
red". ~ when the can turns red.

the pots are sort of pit fired, but VERY black from the concentration
of sawdust & the graphite.

i 1st saw the use of graphite about 10 years ago via ceramics monthly
magazine. the author claimed to get gun metal black results - and i
get very similar.

i sometimes throw pots that look american indian & use this process to
get "low budget" indian pots.

a mad scientist friend of mine says that graphite, as a special form of
carbon, encourages regular carbon to convert to the graphite form in
the firing & that is why the color is richer then usual carbon black.

see ya

steve

In article . com,
steve wrote:
i use about 1 quart of salad oil with 1 teaspoon of graphite. i apply
to bisque pots.

the pots are placed in a metal can surounded with sawdust. i close the
can, and put a brick on the top. in the kiln i fire to about "can
red". ~ when the can turns red.

the pots are sort of pit fired, but VERY black from the concentration
of sawdust & the graphite.

steve

Thanks--this is great info. A couple more questions--do you burnish
first? What claybody do you typically use?

I'm looking forward to trying this out sometime.

Deb R.

thanks for the suggestions, I think I'll try defloculating first,
before mucking about with oil and glue and gasoline!!!??? I've got
some sodium silicate in the workshop.

I'll let you know what happens.

All the best.
Alistair.

(Bob Masta) wrote in message ...
On 10 Apr 2005 11:00:28 -0700, "steve "
wrote:

i guess in a weird way you could put wood in your bowls to burn, ash,
and glaze in the same fire? or pile on raw ash with no water? or what
about mixing ash in Elmer's Glue (that white water based glue) and glue
the glaze to your pot?

i never tried any of this, but their must be a liquid carrier that
could be used to add the ash to the pot without watering down the pot?

i mess around with "black fired" pots where i mix graphite with salad
oil & apply this to bisque pots.

possibly a mix of salad oil & ash would head in your direction?


I've mixed up "regular" (non-ash) glazes using canola oil
instead of water for just this purpose. I wanted to single-fire
some pieces that were bone dry, and may usual water-based
glazes caused the pieces to crack from water re-absorption,
even on a single application to just the inside of the piece.
The oil-based glaze did the trick, but it was a problem to
handle the pieces to get them into the kiln. The oil vanished
into the interior of the clay, leaving the glaze as a powdery
residue on the surface, sort of like the scales on butterfly
wings... the slightest touch would mar it.

Perhaps straight ash in oil wouldn't have this problem.

I've been thinking of other bases instead of this oil, which
might work better, but haven't tried any yet. If I were
going to use this regularly, and not just as an experiment
or "in a pinch", I'd want to find something that not only
worked, but was inexpensive and readily available, and
that didn't release noxious fumes when burning out
in the kiln. There is also the issue of flammability during
the application, if you try other organic sovents, etc.
For example, gasoline might work, but I'm sure not going
to try it! I'll probably try concentrated rubbing alcohol
when I next get into a pinch, but it's too expensive for
everyday use even if it works perfectly.

Anyone have any other suggestions for cheap non-aqueous
bases to try?

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com

sometimes i burnish, sometimes i don't.

i use typically soldate 60 cone 10 clay, but also porcelain sometimes.


the richness of the black is great no matter what the surface finish.

see ya

steve



Deborah M Riel wrote:
In article . com,
steve wrote:
i use about 1 quart of salad oil with 1 teaspoon of graphite. i
apply
to bisque pots.

the pots are placed in a metal can surounded with sawdust. i close
the
can, and put a brick on the top. in the kiln i fire to about "can
red". ~ when the can turns red.

the pots are sort of pit fired, but VERY black from the
concentration
of sawdust & the graphite.

steve

Thanks--this is great info. A couple more questions--do you burnish
first? What claybody do you typically use?

I'm looking forward to trying this out sometime.

Deb R.

sometimes i burnish, sometimes i don't.

i use typically soldate 60 cone 10 clay, but also porcelain sometimes.


the richness of the black is great no matter what the surface finish.

see ya

steve



Deborah M Riel wrote:
In article . com,
steve wrote:
i use about 1 quart of salad oil with 1 teaspoon of graphite. i
apply
to bisque pots.

the pots are placed in a metal can surounded with sawdust. i close
the
can, and put a brick on the top. in the kiln i fire to about "can
red". ~ when the can turns red.

the pots are sort of pit fired, but VERY black from the
concentration
of sawdust & the graphite.

steve

Thanks--this is great info. A couple more questions--do you burnish
first? What claybody do you typically use?

I'm looking forward to trying this out sometime.

Deb R.