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mixing big batches and glazing large platters

updated thu 29 oct 09

 

Rikki Gill on mon 26 oct 09


Hi David,

Why do you think large batches are a mistake? I have good way to do this.

I have asthma and no longer want to put together my dry glazes, so I have
our local clay maker ,using my formulas, put the dry mixed chemicals in
plastic bags for me. I have 50lbs done at one time. I have the bags place=
d
on a table, so I can pour the glaze into the water in large trash cans that
are set on plant movers. I then roll them to a heavy duty slip mixer, and
mix them up for at least 30 minutes, until they are totally smooth. I don'=
t
use a strainer until I decant the glaze into smaller buckets.
I keep the buckets tightly closed when not in use. This system works well=
,
partly because I never let them dry out. For larger pieces, I sometimes dip
directly into the trash cans themselves.
When I make a new batch, I first decant the leftovers into something
smaller, and scrape down the sides and mix with the clean water, so I don't
get any lumps. Then I add the dry glaze and mix it. After testing the new
batch, I add the leftovers. I have been doing this for a few years now, an=
d
I am very happy with this system. It definitely works for me. I use five
main glazes, and 50lbs
of each lasts me about a year.

----- Original Message -----
From: "David Hendley"
To:
Sent: Monday, October 26, 2009 4:49 PM
Subject: mixing big batches and glazing large platters


> Big batches:
> I think it is a mistake for an individual studio potter, even a pro
> who sells a lot, to make glaze batches larger than a pickle-bucket-
> full at a time.
>

David Hendley on mon 26 oct 09


Big batches:
I think it is a mistake for an individual studio potter, even a pro
who sells a lot, to make glaze batches larger than a pickle-bucket-
full at a time.

BTW, it is commonly stated that 10,000 grams is a good amount
to mix to fill a 5-gallon bucket. I find this too little. Depending
on the glaze, I mix 12,000 to 15,000 grams at a time, and the slop
still fits comfortably in a standard issue 5 gallon bucket, with room
for dipping.

BTW #2, "Jason's Deli", a common restaurant chain in these parts,
uses lots and lots of 5 gallon buckets, and they are very happy to
give away the empties. It is not unusual to be able to scarf up 10
or 20 at a time.

Back when I was doing some wholesaling, I decided to mix up
30-gallon trash cans-full of glaze of my most-used glazes. I really
regretted it. The time saved in weighing and mixing was lost in the
extra effort needed to sieve the mixture (you can't pick up 30
gallons of glaze and pour it into another container) and the time
spent keeping the mix well stirred. I also found that the big batches
needed to be re-sieved before they were used up because lumpy
bits of dried glaze would develop. Big batches like this also
discourage experimentation and growth.

Glazing large platters:

The best way to glaze a large platter with a small amount of glaze
is to build your own container. If you have some scrap plywood
around the cost is next-to-nothing. Thin 3/8" plywood is fine.
Start with 2 pieces of plywood a little wider than the platters you
need to glaze, say 20". Make them about 4" taller than wide,
or 24". These will be the sides of your container.

The other 2 sides will be 1 X 4 boards, 23 1/4" long (24" minus
the thickness of the bottom board), and the bottom will be a
1 X 4 board 20" long. Glue and screw the 3 1 X 4s into a U-
shape. Caulk the joints and paint them with any left-over paint.

Paint the 2 pieces of plywood and then attach them to the 1 X 4s.
Run beads of caulk along the edge of the 1 X 4s, then place the
plywood and screw into place.

So, if you are visually following along, you realize that your
platter will be glazed sideways. Simply fill your container, grab the
platter by the rim, and dip it in. The extra height is to accommodate
the rising glaze level as the platter is immersed. After a try or
two, you will know how full the container needs to be to glaze
a platter in only one dip, with no annoying overlaps.

David Hendley
david@farmpots.com
http://www.farmpots.com

David Hendley on tue 27 oct 09


Hi Rikki, I will answer this, since you directly ask me, but I
think I already stated why I think mixing extra-large batches
of glaze is not a good idea for a studio potter in my previous
e-mail.

Just reading over your glaze-making procedure sounds tiring
and like it would take over a good portion of my glazing area --
plastic bags, large trash cans, plant movers, heavy duty slip mixer,
smaller buckets.

I use a scoop, scales, 2 free buckets and a homemade 80-mesh
sieve to measure and mix my glazes.

Your 50 pound batches are actually not that large, not close to
the 30 gallons Mel keeps writing about. My 15,000 gram batches
that fit into pickle buckets translate to 33 pounds.

Of course, if I were having an outside source mix my glazes, who
knows what method I might use, and yours might well be the
most efficient and the optimal quantity. Not many studio potters
have their glazes pre-mixed for them, and I wouldn't give
advice to anyone with health concerns.

Best regards,
David Hendley
david@farmpots.com
http://www.farmpots.com


----- Original Message -----
> Why do you think large batches are a mistake? I have good way to do
> this.
> I have asthma and no longer want to put together my dry glazes, so I have
> our local clay maker ,using my formulas, put the dry mixed chemicals in
> plastic bags for me. I have 50lbs done at one time. I have the bags
> placed
> on a table, so I can pour the glaze into the water in large trash cans
> that
> are set on plant movers. I then roll them to a heavy duty slip mixer, an=
d
> mix them up for at least 30 minutes, until they are totally smooth. I
> don't
> use a strainer until I decant the glaze into smaller buckets.
> I keep the buckets tightly closed when not in use. This system works
> well,
> partly because I never let them dry out. For larger pieces, I sometimes
> dip
> directly into the trash cans themselves.
> When I make a new batch, I first decant the leftovers into something
> smaller, and scrape down the sides and mix with the clean water, so I
> don't
> get any lumps. Then I add the dry glaze and mix it. After testing the
> new
> batch, I add the leftovers. I have been doing this for a few years now,
> and
> I am very happy with this system. It definitely works for me. I use fiv=
e
> main glazes, and 50lbs
> of each lasts me about a year.