Christine Martin on mon 24 jan 05
how do i keep flat clay objects from warping when they dry? before
christmas, i made some simple cookie cutter ceramic ornaments from rolled
out clay and the smaller ones did just fine, but the larger ones warped
quite a bit. i put them on a flat surface and covered with a damp towel so
they wouldn't dry too fast and crack. i would like to do some more of the
larger shapes for various other things and am wondering what i can do to
keep this from happening.
also, i've been reading the plaster thread. what exactly is a plaster table?
is that just a surface to use to dry out your clay pieces?
and last but not least, i've tried googling on pugmill. all i'm getting is
places that sell it, but no explanation on what it does and what it is.
please don't laugh at those questions, i know they may sound dumb to someone
who's been doing this for years and years, but i'm still curious as to the
answers!
christine
william schran on tue 25 jan 05
Christine wrote:>how do i keep flat clay objects from warping when they dry?<
Cover the edges and dry from the middle out.
>what exactly is a plaster table?
is that just a surface to use to dry out your clay pieces?<
Surface used to wedge on or to spread out clay that's too wet, to make dryer.
>i've tried googling on pugmill. all i'm getting is
places that sell it, but no explanation on what it does and what it is.<
Pugmill is a type of clay mixing machine that blends clay through a
chopping action. Some pugmills also have a vacuum chamber for
deairing the clay.
Bill
katetiler on wed 26 jan 05
Keeping things flat as they dry is a question for tile makers! So here
I am :)
The best way to dry flat clay so it doesn't warp or bend is to use a
sheet of plasterboard or I think you call it dry wall board in the USA?
Its gypsum plaster coated in paper sheet that is used to fill in the
gaps between timber and make the walls of modern houses. It comes in
HUGE sheets but is easy to score the paper & then snap the plaster
into managable squares, maybe 2ft square.
Roll out your clay onto this directly or just transfer onto this. If
you have smallish tiles or cut out shapes, just laying it onto a board
will be enough, as the water is drawn down into the board as the top
surface dries, so it dries equally.
If you have large tiles or shapes, you may want to place another sheet
on top, and let the water in the clay be drawn out slowly between the
boards - turn the boards over and swap for new boards every few days
so that the staturated boards don't grow mouldy.
The cause of clay warping is where the top surface dries and shrinks
as it is exposed to the air, but the bottom is sealed against the
surface it is lying on. Using plasterboards helps balance this and
also slows the process down.
The only thing to remember is that the boards aren't strong enough to
be used in drying racks on their own - use a support underneath or
they will bend as they absorb water from the clay.
Hope this helps :)
Kate
http://www.katetiler.co.uk
--- In clayart@yahoogroups.com, Christine Martin wrote:
> how do i keep flat clay objects from warping when they dry?
claybair on wed 26 jan 05
Kate,
I switched to 1/4" Hardibacker for the same purpose.
In addition it's thinner, is a cement product so there's no plaster or
peeling paper, is scored and snapped, no mold issues, can be used as ware
boards, storage takes up less room, costs about $10 for a 4x5 sheet... can
you tell....
I really like this stuff! I also use it for my mosaics.
Gayle Bair
Bainbridge Island, WA
Tucson, AZ
http://claybair.com
-----Original Message-----
From: katetiler
Keeping things flat as they dry is a question for tile makers! So here
I am :)
The best way to dry flat clay so it doesn't warp or bend is to use a
sheet of plasterboard or I think you call it dry wall board in the USA?
Its gypsum plaster coated in paper sheet that is used to fill in the
gaps between timber and make the walls of modern houses. It comes in
HUGE sheets but is easy to score the paper & then snap the plaster
into managable squares, maybe 2ft square.
snip>
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Jan Goodland Metz on wed 26 jan 05
Hi,
Just wanted to add that I went to Home Depot to the "damaged" drywall section
and got 2ft wide pieces for free,. The other thing I would suggest is to tape
the edges after cutting. This system works great for drying tiles.
Jan
In the Rhode Island Tundra where it is snowing again.
Quoting katetiler :
> Its gypsum plaster coated in paper sheet that is used to fill in the
> gaps between timber and make the walls of modern houses. It comes in
> HUGE sheets but is easy to score the paper & then snap the plaster
> into managable squares, maybe 2ft square.
>
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