search  current discussion  categories  techniques - spraying 

spraying raw glazes on bone dry functional pots

updated sun 20 nov 05

 

Maurice Weitman on thu 17 nov 05


Howdy, claybuds,

For several reasons (to save energy, time, and space), I've decided
to migrate to spraying raw glazes onto bone dry pots, mostly
functional ware, from tea bowls to large bowls, vases, and casseroles.

I've been reading books, magazine articles, web pages, and scouring
the archives to learn about it. Not surprisingly, I found many
helpful clayart posts. Even some that don't conflict with others!

I'm prepared to experiment, but I'd appreciate any advice you can
offer to help reduce the slope of the learning curve. My aim is to
be able to spray most of my cone 6 glazes onto a fairly closed, white
body, often in batches of dozens at a time.

First, can you recommend any books or articles for me to read? I
think I've got most of the info I need, but I'd love to learn more
about the actual glazing process, specifically spraying bone-dry
ware. I've read Fran Tristram's Single Firing book, but found little
about spaying, particularly several pieces at once, there.

I planned on starting with some of the glazes I'd been using (^6 ox)
to see how they'd work. I read about adding 1%-2% bentonite or CMC.
I guess that can't hurt, particularly with glazes with not a lot of
clay. Are there reasons to use one instead of the other? Or others,
or none?

One of the conflicts I'm trying to resolve is how to spray many pots
at once to avoid having to change glazes in the gun too often. In
other words, with bisqued pots, I could spray (or even pour) the
liner glaze in as thick as I wanted, then begin spraying all the
outsides when that dried a bit.

I've read that I should/could spray a couple of coats of liner glaze
on several pots if I keep the outside misted to avoid the one-sided
expansion. Seems easy enough. But once the liner's thick enough,
how soon and how aggressively can I apply layers to the outside? Or
should I be more balanced with liner/outside? Ya know where I'm
comin' from?

And how can I avoid sealing in carbonaceous doodoo during the bisque
portion of the single firing? Or should I not worry about that? Huh?

I'd appreciate your help and advice.

Thanks.

Regards,
Maurice

ps I've recently had to change my email address for clayart to this
one; momud2 is a goner. My "permanent" address is just plain "mud"
at the same mo.com domain, though.

Ever wonder what 2000 looks like?

Mark Issenberg on thu 17 nov 05


Hey Maurice , when you get this all fiqured out please write a book about it
and ill buy a copy for sure..

Mark

sitting around the fire

marianne kuiper milks on fri 18 nov 05


Hi Maurice,
Here is a totally Unscientific Answer that works.
I used recipes from the cone 10 glazes book by Michael
Bailey and BRUSHED them on both porcelain 747 ,
Laguna, I believe, and another whatever 2-bits :-) of
throwing clay i had left.

I had dipped a raw piece in glaze once, my very first
firing way back...and was astonished to find a p[ile
of mud on my shelf. However, the brushed pieces I
tried this summer ALL came out to perfection! in fact:
some better than the bisqued/glazed pieces, same clay
and glaze.

I've been contemplating trying it with spraying, cone
6 glazes..one from Roy/Hesselberth, one from a friend,
because it seems closer to brushing than to dipping.
These are non-functional pieces. For edible food, that
is: i hope they will be food for the soul. (so early,
so poetic...i should go and have breakfast.) Let me
know, please, and I will post my results on Clayart as
well. Good luck and have fun experiementing.

Marianne

--- Maurice Weitman wrote:

> Howdy, claybuds,
>
> For several reasons (to save energy, time, and
> space), I've decided
> to migrate to spraying raw glazes onto bone dry
> pots, mostly
> functional ware, from tea bowls to large bowls,
> vases, and casseroles.
>
> I've been reading books, magazine articles, web
> pages, and scouring
> the archives to learn about it. Not surprisingly, I
> found many
> helpful clayart posts. Even some that don't
> conflict with others!
>
> I'm prepared to experiment, but I'd appreciate any
> advice you can
> offer to help reduce the slope of the learning
> curve. My aim is to
> be able to spray most of my cone 6 glazes onto a
> fairly closed, white
> body, often in batches of dozens at a time.
>
> First, can you recommend any books or articles for
> me to read? I
> think I've got most of the info I need, but I'd love
> to learn more
> about the actual glazing process, specifically
> spraying bone-dry
> ware. I've read Fran Tristram's Single Firing book,
> but found little
> about spaying, particularly several pieces at once,
> there.
>
> I planned on starting with some of the glazes I'd
> been using (^6 ox)
> to see how they'd work. I read about adding 1%-2%
> bentonite or CMC.
> I guess that can't hurt, particularly with glazes
> with not a lot of
> clay. Are there reasons to use one instead of the
> other? Or others,
> or none?
>
> One of the conflicts I'm trying to resolve is how to
> spray many pots
> at once to avoid having to change glazes in the gun
> too often. In
> other words, with bisqued pots, I could spray (or
> even pour) the
> liner glaze in as thick as I wanted, then begin
> spraying all the
> outsides when that dried a bit.
>
> I've read that I should/could spray a couple of
> coats of liner glaze
> on several pots if I keep the outside misted to
> avoid the one-sided
> expansion. Seems easy enough. But once the liner's
> thick enough,
> how soon and how aggressively can I apply layers to
> the outside? Or
> should I be more balanced with liner/outside? Ya
> know where I'm
> comin' from?
>
> And how can I avoid sealing in carbonaceous doodoo
> during the bisque
> portion of the single firing? Or should I not worry
> about that? Huh?
>
> I'd appreciate your help and advice.
>
> Thanks.
>
> Regards,
> Maurice
>
> ps I've recently had to change my email address for
> clayart to this
> one; momud2 is a goner. My "permanent" address is
> just plain "mud"
> at the same mo.com domain, though.
>
> Ever wonder what 2000 looks like?
>
>
>
______________________________________________________________________________
> 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.
>



__________________________________
Start your day with Yahoo! - Make it your home page!
http://www.yahoo.com/r/hs

Jenny Lewis on fri 18 nov 05


Hi Maurice

Fran Tristram's book is terrific, but she has changed her style of work since
it was published! She now sprays her pots - if you do a Google image search,
there are some pictures of her recent stuff on the web. Dry-ish matt
surfaces, tall slender pitchers, donut thingies - very nice.

I did a weekend workshop with her a couple of years ago. I wasn't using the
sprayer myself, but as far as I recall which is not very far - lightly mist
bone-dry work on the outside with water sprayer, like you use for plants;
pour-n-swirl inside, leave to dry again, then spray outside. I think she glazes
the insides of a whole bunch of pots, by the time the last one is done, the
first one is just about ready to spray. I don't remember her spraying more than
one at a time, but it's a very quick process. Some of them are two different
colours - spray one side of each, then the other. If your booth is large
enough, don't see why you can't line them up and do more than one at a time?

My plan was to do single firing always and forever, but at the moment I am
back to bisc. Partly because I make such a mess when I'm glazing - last week I
scrubbed several pots clean and reglazed them and that cannot happen with raw
clay! I do double dipping, overlapping, pouring and dribbling, and it was a
bit awkward to do on rapidly softening pots. I may try again sometime. Also,
a few of my favourite glazes don't have enough clay content. I decided to try
them anyway to find out what happens, and they just fell off the test pots,
some of them even before they got into the kiln. So now I know.

Good luck with the process,

Jenny Lewis
in Eastleigh, UK
nice crispy frosty day, perfect for a glaze firing
which I'm doing

pdp1@EARTHLINK.NET on fri 18 nov 05


Hi Maurice,


I recall no troubles of any kind in what Glaze spraying I was doing, and my
pieces tended to be 'Bone-Dry' indeed.

I merely set them on the Wheel and had them rotate slowly as I sprayed, or
sometimes I set them on something to elevate them somewhat on the Wheel
Head, to let me have a better angle...

It was easy to keep the interior glaze distinct from the exterior Glaze, or
with a fine transition, since the exterior tended in my case to be sprayed
with the Bowl upside-down, and when spraying the interior, I merely leaned
into it from above somewhat.

I myself did not like dipping the Bowls into Glazes, and sometimes I only
made a pint of some Glaze anyway, so the Spraying was much more
satisfactory.

Now, of course, one is well advised to do one's spraying where one is not
breathing the airborne mists of it...by one means or another.

But...

If you need heavier applications than you feel are prudent to apply at one
continuous time, then (having the pieces on Bats, certainly, makes it easy
to set them back on the wareboard with no fingermarks ) maybe just apply as
much as you feel safe to do, set aside, do the next, and once done with some
dozen or so, return to the first one for it's additional application to get
the thickness you want it to have for that particular Glazes' best
performance.

Unless I am missing something here, I would not expect you to have any
problems.

I suppose, you could experiment also to use as relatively 'thick' a Glaze as
the Spray Gun will be comfortable with, which of course imparts less Water
then, to the piece being sprayed...

I know some of mine were rather fragile, that is, if you touched the dried
Glaze it could come off in powder, but so long as I was careful in how I
handled Glazed pieces, I had no problems.

Most everyone else I think has the sense to add certain things to increase
the adherance and tenacity, but, Lol...

How's that 'new' Air Compressor doing?


Best wishes!

Phil
Las Vegas


----- Original Message -----
From: "Maurice Weitman"


> Howdy, claybuds,
>
> For several reasons (to save energy, time, and space), I've decided
> to migrate to spraying raw glazes onto bone dry pots, mostly
> functional ware, from tea bowls to large bowls, vases, and casseroles.
>
> I've been reading books, magazine articles, web pages, and scouring
> the archives to learn about it. Not surprisingly, I found many
> helpful clayart posts. Even some that don't conflict with others!
>
> I'm prepared to experiment, but I'd appreciate any advice you can
> offer to help reduce the slope of the learning curve. My aim is to
> be able to spray most of my cone 6 glazes onto a fairly closed, white
> body, often in batches of dozens at a time.
>
> First, can you recommend any books or articles for me to read? I
> think I've got most of the info I need, but I'd love to learn more
> about the actual glazing process, specifically spraying bone-dry
> ware. I've read Fran Tristram's Single Firing book, but found little
> about spaying, particularly several pieces at once, there.
>
> I planned on starting with some of the glazes I'd been using (^6 ox)
> to see how they'd work. I read about adding 1%-2% bentonite or CMC.
> I guess that can't hurt, particularly with glazes with not a lot of
> clay. Are there reasons to use one instead of the other? Or others,
> or none?
>
> One of the conflicts I'm trying to resolve is how to spray many pots
> at once to avoid having to change glazes in the gun too often. In
> other words, with bisqued pots, I could spray (or even pour) the
> liner glaze in as thick as I wanted, then begin spraying all the
> outsides when that dried a bit.
>
> I've read that I should/could spray a couple of coats of liner glaze
> on several pots if I keep the outside misted to avoid the one-sided
> expansion. Seems easy enough. But once the liner's thick enough,
> how soon and how aggressively can I apply layers to the outside? Or
> should I be more balanced with liner/outside? Ya know where I'm
> comin' from?
>
> And how can I avoid sealing in carbonaceous doodoo during the bisque
> portion of the single firing? Or should I not worry about that? Huh?
>
> I'd appreciate your help and advice.
>
> Thanks.
>
> Regards,
> Maurice

Bobbruch1@AOL.COM on sat 19 nov 05


Another thought about glazes on bone dry
functional pots: If you are layering glazes,
you can sometimes get different effects by
brushing or spraying one glaze on the
greenware and then applying
the second glaze when it is bisqued.

Some layered glazes will be different if you
layer the glazes in different firings vs layering
them one over the other on bisqueware.=A0 The only
way to determine that is by experimenting.

Bob Bruch