Snail Scott on mon 7 jan 08
> Date: Sat, 5 Jan 2008 09:13:09 -0500
> From: Martha Rogala
> ...the raku that I've done doesn't hold up well
> to our winters here (near Buffalo, NY). Does anyone know a way to seal
> raku so that it will be durable enough to handle our freeze/thaw issues
> here? ...or is there any other way that anyone can think of to get
> this to
> work?
I have had good luck with Water Warden, but I've only
used it on unglazed ware, and I wonder if glaze would
interfere with adequate absorption of the product. If
new cracks open up in the glaze, water might penetrate
to area where the sealant didn't get absorbed, and the
glaze would then act to retain the moisture inside. For
freezing, glaze over an absorbent body is worse than
no glaze at all.
I first used Water Warden when a low-fire commission
intended for southern Arizona fell through after
completion, and a buyer in the Sierras wanted to
acquire the piece. It seems to have preserved the
piece well, but the form was unglazed, and had good
drainage, and the buyer then moved to Marin County,
which ain't Tucson, but it's a far cry from the Sierras
(or Buffalo).
Of critical importance to any outdoor sculpture in clay
is to create forms which trap no water. When it expands
as ice, it won't matter now impervious your clay body
is, it will crack from the pressure. Beware of potential
puddles, but also of crevices and even moderate
texture where surface tension can hold moisture long
enough to freeze.
What might worry me also is the physical fragility of
raku in a populated public environment, especially
in a school.
Can you achieve the intended aesthetic goal in a
more frostproof material? Please consider it, if only
as a courtesy to your collaborator, whose efforts will
also go to waste if your components do not stand the
test of time.
-Snail
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