COLUMBIA

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... sUpplier of your ceramic and pottery needs.

Announcing Georgies new Cone 6 crackle glazes:

GLW48 Cicada
GLW49 Peking Blue
GLW50 Dragon Scale
GLW51 Wu Blue
GLW52 Dynasty Grey
GLW53 Yangtze Amber

In store now, The Steve Tool,
the ultimate texturing tool!

Hours: Drop by and check
. us out:
TUTE ee le) #109 - 18525 - 53 Ave.

9:30 a.m. to 5 p.m. Surrey, B.C.

Saturday

Or give us a call at:
9:30 a.m. to 1:30 p.m.

604.574.0454

JUDY WEEDEN

POTTERY WORKSHOP

On SALTSPRING ISLAND

July 19-31, 2010

This course is designed to be a time for the
total immersion in the creative process for
students seriously committed to working
with clay. It is a process-oriented
workshop. Students at any level of previous
experience will find invaluable stimulation
and new skills.

LOCATION
Country studio of Judy Weeden
125 Primrose Ln, Saltspring Island
Tuition
$600 Cdn, Space limited to 8 students
Further information and application
www.judyweeden.com
or write Judy Weeden
125 Primrose Ln
Saltspring Island, BC, V8K 1C1

Thurs., Oct. 22, 2009—reprinted from a blog on Technology
Review, published by the Massachusetts Institute of Technology
(it's comforting to know that tomorrow's Nobel Laureate scientists
are on our side, hard at work resolving our pottery issues—Ed,):

Death of the Teapot Effect

Fluid dynamicists have

(a) (a’)
worked out how to stop

teapots from dribbling,

once and for all.

Teapot technology is

largely ignored by main- (b) ib’)
stream media (some say

unfairly.) But today,

scientists in France

unveil a technique

that should breathe hi-

tech life into a new

generation of be-spouted objects.

The problem with teapots is their annoying habit of dribbling,
particularly at low rates of flow. The phenomenon has achieved such
notoriety that it has been imaginatively dubbed the "teapot effect.”

Previous studies have shown that dribbling is the result of flow
separation where the layer of fluid closest to the boundary becomes
detached from it. When that happens, the fluid fows smoothly over
the lip. But as the flow rate decreases, the boundary layer re-attaches
to the surface causing dribbling.

Previous studies have shown that a number of factors effect this
process such as the radius of curvature of the teapot lip, the speed
of the flow and the “wettability” of the teapot material. But a full
understanding of what's going on has so far eluded scientists.

Now Cyril Duez at the University of Lyon in France and a few amis,
have identified the single factor at the heart of the problem and shown
how to tackle it. They say that the culprit is a "hydro-capillary” effect
that keeps the liquid in contact with the material as it leaves the lip.
‘The previously identified factors all determine the strength of this
hydro-capillary effect.

So how to overcome it? There are two ways say Duez and co. The
first is to make the lip as thin as possible. That's why teapots with
spouts made from thin metal are less likely to dribble.

‘The second is to coat the lip with the latest generation of super
hydrophobic materials which strongly repel water. Duez and co show
how this stops dribbling at a stroke. "Super hydrophobic surfaces fully
avoid dripping, and thus beat the "teapot effect",” they say.

(Of course, there are one or two other potential applications in
shaping the fluid fow in microfluidic machines but these pale into
insignificance compared with the teapot revolution in hand.)

‘The really exciting news, however, is that in certain materials the
hydro-capillary effect can be controlled electronically. That raises the
possibility of a teapot design in which dribbling can be turned on and
off with the flick of a switch--an object of desire on a par with the
iPhone, USB catapults and personal hovercrafts. (The iPot, perhaps?)

If this doesn't win these guys an IgNobel, I don't know what will.

The following is a response posted by bart889 on Oct. 28/09:

In my family, we solved this problem by applying a high-tech ultra
hydrophobic coating to the teapot spout.

The coating substance is commonly referred to as "butter".

Potters Guild of BC Newsletter - February 2010 12