dayton j grant on thu 16 may 02
Hey Tony,theres a few things that I know about drying clay as fast as
possible...
WIND is the primary thing that moves moisture out of a claybody ,while
HEAT (at the drying stage of production )is secondary ,and is most
useful in very small amounts,(like a candle or an oil lamp) in
conjunction with a controlled draft, to encourage one part of a given
peice ,to dry (or become brittle) before another, so with things like 20"
platters and larger peices in general ,you definitely want the central
area to dry (or become brittle) before the outer edge, because if the
outer edge(lip) shrinks and becomes brittle before the center(floor) then
the center area will be pulled outward in every direction like a drumskin
,which will 'tear' the leather hard clay giving the appearance of a
'crack'(I think a crack is from an impact while a tear is from
tension,right?),while on the other hand if you solidify(dry) the center
area first, the most common effect is that the diameter of the
circumfrence will be diminished (the mouths of cylinders will shrink a
little and the lips of plates and platters will 'cup' and raise a
little),one good way to ensure the proper and timely drying of plates and
platters is to make a 'chuck' or just a cylinder that is the same
diameter as the foot of the peice ,put couple of airholes in it ,put a
candle or a small oil lamp in it and put the plate directly on top of it
so that the heat from the candling flame is isolated to the area inside
of the footring on the bottom of the peice ,and when youre pretty sure
that the center area is going to solidify before the rest of the peice
take it off of the candling flame(or not) and put a strong fan on it to
accelerate the drying process once you have used the candling flame to
determine which part(s) will dry first ,there are some other conditions
to consider like the thickness of the lip relative to the rest of the
peice,whether or not there are any joints, handles,cutouts,.. stuff like
that,..good luck with your show.
D.G.
Tony Ferguson on thu 16 may 02
WOw, thank you for this explanation and technique. My lips are thick as I
have found they tend not to crack and I like them beefer. So, should I
leather hard dry the centers first and then dry with a fan? The porcelain I
am using is Continetal clay grolleg porcelain with a little fiber. Thanks!
Thank you.
Tony Ferguson
Stoneware, Porcelain, Raku
www.aquariusartgallery.com
218-727-6339
315 N. Lake Ave
Apt 312
Duluth, MN 55806
----- Original Message -----
From: "dayton j grant"
To:
Sent: Wednesday, May 15, 2002 8:25 PM
Subject: porcelain drying 'methods'
> Hey Tony,theres a few things that I know about drying clay as fast as
> possible...
> WIND is the primary thing that moves moisture out of a claybody ,while
> HEAT (at the drying stage of production )is secondary ,and is most
> useful in very small amounts,(like a candle or an oil lamp) in
> conjunction with a controlled draft, to encourage one part of a given
> peice ,to dry (or become brittle) before another, so with things like 20"
> platters and larger peices in general ,you definitely want the central
> area to dry (or become brittle) before the outer edge, because if the
> outer edge(lip) shrinks and becomes brittle before the center(floor) then
> the center area will be pulled outward in every direction like a drumskin
> ,which will 'tear' the leather hard clay giving the appearance of a
> 'crack'(I think a crack is from an impact while a tear is from
> tension,right?),while on the other hand if you solidify(dry) the center
> area first, the most common effect is that the diameter of the
> circumfrence will be diminished (the mouths of cylinders will shrink a
> little and the lips of plates and platters will 'cup' and raise a
> little),one good way to ensure the proper and timely drying of plates and
> platters is to make a 'chuck' or just a cylinder that is the same
> diameter as the foot of the peice ,put couple of airholes in it ,put a
> candle or a small oil lamp in it and put the plate directly on top of it
> so that the heat from the candling flame is isolated to the area inside
> of the footring on the bottom of the peice ,and when youre pretty sure
> that the center area is going to solidify before the rest of the peice
> take it off of the candling flame(or not) and put a strong fan on it to
> accelerate the drying process once you have used the candling flame to
> determine which part(s) will dry first ,there are some other conditions
> to consider like the thickness of the lip relative to the rest of the
> peice,whether or not there are any joints, handles,cutouts,.. stuff like
> that,..good luck with your show.
> D.G.
>
>
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