search  current discussion  categories  forms - misc 

slip pump and glazing large bowls

updated sun 24 apr 05

 

Vince Pitelka on sat 16 apr 05


> Man, that seems like an awful long time to have glaze on the inside of a
> bowl, getting thicker, and thicker, and thicker....

I'm with Earl Brunner on this. When glazing, the idea is to apply an even
coat of glaze, and if pouring the glaze, to pour it in and then pour it out
quickly, in order to give an even coating. If you don't want to pour the
glaze back out, then why not spray the glaze instead of pouring? And even
if you did pump the glaze out, how would you get the last liquid residue
down in the bottom of the bowl? Your only choice would be to pour it out,
because to do otherwise would damage the glazed surface in the bottom of the
bowl. And if you pour it out, you will be pouring it over the upper surface
that has been drying while you pump out the glaze. If you leave any excess
residue of liquid glaze in the bottom of the bowl, it will likely crack and
peel as it dries. And then there is the whole issue of the glaze residue on
the inside of the pump and hoses. Unless you were doing vast amounts of
glazing with a single glaze, I am afraid that you would loose a lot of glaze
every time you wash out the system to change to another glaze.

I love the idea of coming up with unusual solutions for all the challenges a
potter faces. We discover all sorts of great things that way. But like
many people on this list, I think in terms of practical mechanics and
spatial relationships. Initially this sounded like a great idea, but the
more I thought about it, the more problems came to mind. I'd hate to see
you invest in expensive pumping machinery only to discover that you get a
flawed product.

I don't know the size of the bowls you are glazing, but let me suggest an
alternative. This will only work if you are using the same glaze inside and
out, but it might be a good solution for you. You could always spray
stains, oxides, or other glazes over the base coat on the inside of the bowl
to give contrast between inside and outside. About thirty years ago, at a
flea market I purchased a 36"-diameter restaurant wok for a dollar. Mostly
I use it for glazing large platters and bowls, and in my experience, it is
about the best thing available for that. With five gallons of glaze in the
wok, you can glaze the largest bowls or platters. To do so, you grasp a
large platter or bowl with two fingers spread wide on each hand, with the
hands on opposite sides of the bowl. Dip the platter or bowl in from one
edge, tilt and swirl it around to coat all surfaces, and follow through, so
that the first edge to enter the glaze is the first to leave, shaking it off
slightly to encourage drips to fall away. Properly done with a proper
consistency of glaze, this can give a very even glaze coating. You just
touch up the finger marks on the rim with a brush, and the piece is glazed.
Or, you can do as I did and make special three-legged tongs to support the
bowl as you dip it. With strong hands, the tongs I made are capable of
holding bowls or platters up to 24" in diameter. If anyone is interested, I
could post a picture of them on my website in the near future.

I wish you the best of luck with this project.
- Vince

Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/

Jo Smith on sat 16 apr 05


of coarse someone would be interested in the tongs, please post and how's
the leg?

Jo

> Or, you can do as I did and make special three-legged tongs to support the
> bowl as you dip it. With strong hands, the tongs I made are capable of
> holding bowls or platters up to 24" in diameter. If anyone is interested,
I
> could post a picture of them on my website in the near future.
>
> >
> >

Louis Katz on sat 16 apr 05


I visited a jiggering factory in Lampang Thailand in 1989.
They worked an 8 hour day with three jiggers turning out a pot about
once every 45 seconds on each of three jiggers. They were fired in
saggars in to about cone 9 (porcelain non translucent, celadon) The
factory was huge and had three or four working large tube kilns. I
don't know if they worked every day.
The pots were glazed on the inside by upturning them over a fountain of
glaze. and passed to the next worker who glazed the outside by grabbing
the inside of the bowl with a damp suction cup and dipping the outside.
(This glazing descriptions sounds reversed. I shoud go look at the
video.
Clay was produced by wet pan followed by seiving settling, blunging and
then pumping into a filter press.
It was a very cool place.
I would be looking for a pneumatic bellows pump.
Louis

On Apr 16, 2005, at 11:52 AM, Vince Pitelka wrote:

>> Man, that seems like an awful long time to have glaze on the inside
>> of a
>> bowl, getting thicker, and thicker, and thicker....
>
> I'm with Earl Brunner on this. When glazing, the idea is to apply an
> even
> coat of glaze, and if pouring the glaze, to pour it in and then pour
> it out
> quickly, in order to give an even coating. If you don't want to pour
> the
> glaze back out, then why not spray the glaze instead of pouring? And
> even
> if you did pump the glaze out, how would you get the last liquid
> residue
> down in the bottom of the bowl? Your only choice would be to pour it
> out,
> because to do otherwise would damage the glazed surface in the bottom
> of the
> bowl. And if you pour it out, you will be pouring it over the upper
> surface
> that has been drying while you pump out the glaze. If you leave any
> excess
> residue of liquid glaze in the bottom of the bowl, it will likely
> crack and
> peel as it dries. And then there is the whole issue of the glaze
> residue on
> the inside of the pump and hoses. Unless you were doing vast amounts
> of
> glazing with a single glaze, I am afraid that you would loose a lot of
> glaze
> every time you wash out the system to change to another glaze.
>
> I love the idea of coming up with unusual solutions for all the
> challenges a
> potter faces. We discover all sorts of great things that way. But
> like
> many people on this list, I think in terms of practical mechanics and
> spatial relationships. Initially this sounded like a great idea, but
> the
> more I thought about it, the more problems came to mind. I'd hate to
> see
> you invest in expensive pumping machinery only to discover that you
> get a
> flawed product.
>
> I don't know the size of the bowls you are glazing, but let me suggest
> an
> alternative. This will only work if you are using the same glaze
> inside and
> out, but it might be a good solution for you. You could always spray
> stains, oxides, or other glazes over the base coat on the inside of
> the bowl
> to give contrast between inside and outside. About thirty years ago,
> at a
> flea market I purchased a 36"-diameter restaurant wok for a dollar.
> Mostly
> I use it for glazing large platters and bowls, and in my experience,
> it is
> about the best thing available for that. With five gallons of glaze
> in the
> wok, you can glaze the largest bowls or platters. To do so, you grasp
> a
> large platter or bowl with two fingers spread wide on each hand, with
> the
> hands on opposite sides of the bowl. Dip the platter or bowl in from
> one
> edge, tilt and swirl it around to coat all surfaces, and follow
> through, so
> that the first edge to enter the glaze is the first to leave, shaking
> it off
> slightly to encourage drips to fall away. Properly done with a proper
> consistency of glaze, this can give a very even glaze coating. You
> just
> touch up the finger marks on the rim with a brush, and the piece is
> glazed.
> Or, you can do as I did and make special three-legged tongs to support
> the
> bowl as you dip it. With strong hands, the tongs I made are capable of
> holding bowls or platters up to 24" in diameter. If anyone is
> interested, I
> could post a picture of them on my website in the near future.
>
> I wish you the best of luck with this project.
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft, Tennessee Technological University
> Smithville TN 37166, 615/597-6801 x111
> vpitelka@dtccom.net, wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka/
> http://www.tntech.edu/craftcenter/
>
> _______________________________________________________________________
> _______
> 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.
>

Dan Saultman on sat 16 apr 05


The Glaze Pump Idea (see previous posts) seems to break the rules of=20
getting the liquid in and out of a vessel quickly and smoothly. Thank=20
you for your observations on that aspect. However, I am trying to make=20=

a clean glazing break from interior to exterior of bowls and vessels,=20
using completely different glazes=97 this requires a focused eye in =
order=20
to making the break at the rim nice and clean.

I was feeling out the (our clayart group) community. It's appreciated=20=

that you can throw out an idea and see if it's practical or not.

In the end, the feedback suggests that it is going to be tough to get=20
the glaze out of a vessel with a suction device, like a pump=97the glaze=20=

will become too thick while this process is taking place. Yet, I can't=20=

quite give it up. Maybe there are out-pouring techniques that should=20
refine or haven't mastered.

Spraying is a concern since a parabolic shape (like a bowl) will send=20
the over spray right back at you.

Many thanks to you all.

Dan


Dan Saultman
Detroit
http://www.saultman.com


On Apr 16, 2005, at 12:52 PM, Vince Pitelka wrote:

>> Man, that seems like an awful long time to have glaze on the inside=20=

>> of a
>> bowl, getting thicker, and thicker, and thicker....
>
> I'm with Earl Brunner on this. When glazing, the idea is to apply an=20=

> even
> coat of glaze, and if pouring the glaze, to pour it in and then pour=20=

> it out
> quickly, in order to give an even coating.

primalmommy on sat 16 apr 05


Two thoughts:

First, I have figured out that I can glaze the inside of a SMALL bowl --
like in the center of a doouble walled bowl, or a small cup -- by using
a turkey baster. Suck up glaze from the bucket, squirt into the bowl,
re-suck, and re-squirt it back in the bucket. This might not be useful
for larger bowls unless you had a bulb the size of your head, but it
seemed like a useful little trick.

When I am doing big bowls with different glazes inside and out, I glaze
the outside first, let it dry, and then paint wax around the top/rim
edge of the glazed surface, being careful not to wax the unglazed edge
of the rim. I then glaze the inside by pouring a big bucket of glaze
into the bowl -- filling to or almost to the rim -- and then quickly but
in one fluid motion rolling the bowl away from me to dump the glaze,
ending up with the bowl completely upside down for a good long
hold-and-drip. It helps to have REALLY BIG glaze bucket to pour back
into -- like a rubbermaid storage tub, maybe with the lid propped in it
as a backsplash. I always mop before I glaze so if I have a spill, I can
sponge or scoop up what's on the floor to return to the bucket. Glaze
ain't cheap.

Yours
Kelly in Ohio.. all the males of the house camping with cub scouts or
boy scouts, so Molly and I are having a lovely "girls only" weekend...
planting herbs and pansies in window boxes, puttering around the studio,
restaurant dinner and a bubble bath...


_______________________________________________________________
Get the FREE email that has everyone talking at http://www.mail2world.com

250MB & 2GB Email Accounts POP3 Calendar SMS Translator - Much More!


ASHPOTS@AOL.COM on sun 17 apr 05


I glaze bowls and platters every firing,, I have 3 sinks in the next
firing,, Two for the new house..
Ive been spraying glaze for years now,, it is the easiest way to glaze big
bowls and platters for me. When i mix up my ashglaze i only mix what i can can
use in 2 days of glazing,, Most of the time i mix 2,000 grams..

For me its the easiest way to get the coat of glaze the way i want it. I
actually spray all my pots even my mugs..


Mark
Dogwoods are flowering all over the Mtn and the Arisemias [ pitcher plants ]
are going wild at the Pocket,, Also lots of watercress at the spring at the
Pocket and lots of Blue Bells , Celadine Poppies and all kinds of spring wild
flowers there also

Vince Pitelka on sun 17 apr 05


Dan Saultman wrote:
"The Glaze Pump Idea (see previous posts) seems to break the rules of
getting the liquid in and out of a vessel quickly and smoothly. Thank
you for your observations on that aspect. However, I am trying to make
a clean glazing break from interior to exterior of bowls and vessels,
using completely different glazes=97 this requires a focused eye in order
to making the break at the rim nice and clean."

Dan -
I think that the solution to your problem is actually pretty simple, and=20
Kelly Savino already posted about the technique today. If it were me, I'=
d=20
glaze the inside first rather than the outside as Kelly suggests. Depend=
ing=20
on the shape of the bowl, if you glaze the outside first, then when pouri=
ng=20
the inside glaze back out, you run the risk of dribbling over the glazed=20
outside surface.

This technique assumes that your glaze division is right at the rim, or j=
ust=20
over the rim. Glaze the inside by the simple pour in, slosh around, and=20
pour out method, making sure that the glaze flows over the rim all the wa=
y=20
around the pot. This can take some clever manipulation, but you will get=
=20
used to it.

On a good ball-bearing banding wheel, paint a broad swath of wax resist o=
r=20
latex over the inside glaze, coming right up to the crisp line that you=20
desire for the division between glazes. If you use wax resist, you may h=
ave=20
to thin it slightly with water to get smooth brushing characteristics.

When the wax is dry, sponge off any glaze that is above the wax line. Be=
=20
careful, because you can damage the wax resiste coating. That is an=20
advantage of latex.

Place the banding wheel inside a broad wide pan that is larger in diamete=
r=20
than the rim of the bowl, like a plastic or metal oil-change pan. Place =
the=20
bowl upside down on a soft pad on the banding wheel. With a pitcher full=
of=20
glaze, pour glaze at the foot so that it flows smoothly over the bowl and=
=20
off the rim as you rotate the banding wheel. With a little practice, you=
=20
can get a very smooth, even coating of glaze.

If your bowl is not deeply curved, spraying the glaze will also work just=
=20
fine. It only becomes a problem on a deep bowl. Keep in mind that an HV=
LP=20
spray system has a much higher transfer rate with far less overspray, so =
if=20
you are planning on doing lots of these bowls, you might want to upgrade =
to=20
HVLP.
Good luck -
- Vince

Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/=20

jesse hull on sun 17 apr 05


I disagree folks, -and think the premise holds
promise.
I guess I saw the bowls in question as too big or
awkward to lift and pour w/o disturbing the perfect
line that Dan wanted to achieve. All of the responses
to the pump idea were justified by everyone's own
experience and the basic concepts of glazing.
However, I think it may be being dismissed a tad
early.
My response to Dan's idea concerned a pump that would
pull the glaze through a hand-held flexible tube set
in the bowl, travel through the pump and then out via
another tube into the glaze container... basically,
the descriptive mechanics of an inline, nonsubmersible
pump. The pump itself would never have to be set
into the bowl, and a skilled hand could easily suck
all the glaze out with little to no disturbance to the
coating that had formed.
I also understand the concern of having the glaze sit
for awhile, thereby getting too thick. I spoke of my
experience in a greenhouse... honestly, if you ever
see one of those pumps move liquid, you'll never
question the lack of speed...
Lastly, cleaning/ changing glazes is a quick fix. I'd
do it just like I switch glazes in my sprayer. I
unscrew the canister, put the feed tube in a bucket of
water, and pull the trigger. Within seconds another
canister can be attached. A pump of the kind I
suggested would clean itself and it's tubeing the
same way very, very quickly.

Just a continued thought.

~jessehull.

ELizabeth Gowen on fri 22 apr 05


I use a method similar to Kelly's but use a bulb irrigation syringe like
those at the site below. Half way down the page with the greenish bulb =
on
them( used to get the unused ones from the OR years ago and loved them) =
I
like one for each color, and for a buck or 2 these are feasible.=20
For large bowls where I have masked out ( with liquid wax) a
separate rim color, I use a soup ladle to put in near the amount of =
glaze
I'll need. Carefully swirl it then suck out the remainder with the bulb
syringe. Works great and you get better with estimating glaze amounts =
with
time. No drip over the edge.
Mind you I have a roller pump that I thought would be useful but the
ladle and syringe method is quick and easy.

http://www.continentostomystore.com/Merchant2/merchant.mvc?Screen=3DCTGY&=
Store
_Code=3DCOS&Category_Code=3DACCIS

The above site is just one I pulled from a search irrigation syringes. I
have not ordered from this particular one.

Liz Gowen

Subject: Re: Slip pump and glazing large bowls


Kelly said:
First, I have figured out that I can glaze the inside of a SMALL bowl --
like in the center of a doouble walled bowl, or a small cup -- by using =
a
turkey baster. Suck up glaze from the bucket, squirt into the bowl, =
re-suck,
and re-squirt it back in the bucket.