search  current discussion  categories  kilns & firing - shelves & furniture 

question: re: shells and wads

updated wed 22 oct 03


Hollis Engley on mon 20 oct 03

----- Original Message -----
From: Susan Cline
Sent: Monday, October 20, 2003 9:58 AM
Subject: Question re: shells and wads

> Perhaps a stupid question, but here goes:
> I understand that shells are used effectively in wood firing, both as
decoration and as support, but here's the question: Can I use shells as
support (stilts?) at ^6 Oxidation? And a related question: can I use
"wadding" at that temp? If so, how does one mix the wadding material? etc?

Hi, Sue. When we use scallop or other ridged shells in a wood kiln, we fill
them with wadding. By themselves, the shells would crumble in the high
temperatures and they wouldn't support the pots. The wadding inside them
helps support the deteriorating shell and the pot itself, keeping the pot
from being welded to the shelf by the wood ash and - in the back chamber -
by the salt. Usually the only evidence remaining of the shell's presence
during the firing is a few almost-parallel lines that mark the pot. That
decoration is exactly the point of using the shell. (Most of the rest of the
pots in the kiln just use straight wads.)
So I wouldn't think you should trust the shell alone as a pot support, even
in the relatively cooler cone 6 atmosphere. You could fill it with wadding,
I suppose, but I'm not sure what the point would be then, since it seems
unlikely that the shell would leave any evidence of its presence in a cone 6
oxidation firing. Seems like it would be better to use the wadding alone.
And, to tell you the truth, I don't understand why you would use wadding,
anyway. If you're using clay patties or kiln wash to alleviate the
accidental runny glaze problem, I'm guessing the wads would be a poor
replacement, since the glaze would run off the pot around the wads and onto
the shelf, anyway.
Hollis Engley
Hatchville Pottery
Falmouth, Mass.