Re: (ATM) Ceramic tool quiry & first post

[Stephen Tonkin <astro@aegis1.demon.co.uk>]

In message <DKw7+pUkOkA@banyan_abq3.aquilagroup.com>
kferguson@aquilagroup.com writes:
> 
> Advantages: Tool is very thick, so I won't wear through tiles.  No cutting of 
> tiles to fit round plaster.  No loose tiles, ever. Will take about same time 
> to make as tile tool, because plaster needs a week to dry out (according to 
> guy at ceramics store) , same as clay.
> 
> Now my questions:
> 
> 1) Will this tool work?  Anyone tried this before? Anything to look out for?

I hope to hell I'm wrong in what I'm about to say!

I think you may have problems looming.  I have done quite a bit of
clay modelling and also taught a bit of it -- I have never tried
firing anything thick because I was taught that anything over about
0.5 to 0.75 inches should be hollowed.  I was told that the whole
kaboodle can shatter or explode if it is too thick, owing to the lack
of escape route for internal moisture as it vaporises, or trapped air,
inside a fired surface.  I've never tried firing large solid objects
because all my firing has been done in a kiln where other people have
things and I have not wanted to risk damage to their works of art.

Whenever I have made clay models, these have been hollowed out and the
hollow has been given access to the exterior by use of a skewer.  I
have in front of me a bull which has a hole in each foot and nostrils
that lead to his belly-hollow.

> 2) I have lost 1/2" to 3/4" diameter due to shrinkage as this tool dried. 

Clay will always shrink as it dries -- you may also find that this
shrinkage causes cracks and weaknesses.

I have also found that large lumps of clay change shape as they dry.

It may be that all I have been taught (and have accepted) is unfounded
mythology.  I hope you will be able to reply telling me that my fears
for your tool are unfounded and that this is a viable method of
tool-making.  After all, one can (or could) purchase ceramic tools.  I
look forward to hearing the results of your experiments.  If it works,
I shall do it!

Clear Skies,
Steve          <sft@aegis1.demon.co.uk>

                   *** SAVE A STAR --- Kill a Light ***