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moldy plaster wedging table

updated tue 2 dec 03

 

Allyson May on sun 30 nov 03


Hey Mary Ellen,

I have done this same thing. Poured a lovely wedging table but didn't =
let it dry long enough before putting on the canvas cover. Just wash =
the whole table down with bleach water and then let it dry out =
completely. A dehumidifier or a fan will speed the process along. The =
bleach does not seem to affect the plaster and my table has not shown =
any sign of the mold returning.
Peace,
Allyson May
Stoney Creek Pottery
Bloomington, Indiana

Janet Kaiser on mon 1 dec 03


Are you really sure it is mould and not the wet plaster pushing
out crystals? A white furry bloom? A large area of new plaster
needs some time to dry and "cure" and if it is in a humid and/or
cold place, it will take a very long time indeed. It sounds like
you have put some thought into a strong wedging table and made a
"thorough job" of it, BUT by so doing, you have added to the
problem by enclosing the plaster on the bottom and the sides!
Where is all that water you put in to make to plaster to go? It
only has one surface to escape and in the rush, it is pushing up
stuff out of the plaster too. Does that make sense? You will also
have a problem in the future... The escape route downward has
effectively been cut off...

But first things, first... It sounds to me like you need to
facilitate the initial drying process with heating, ventilation,
air-circulation and reduction of humidity levels, but NOT add to
the moisture with any liquid (including a bleach solution). It
would be best if you could remove the plaster from the table.
Keep wiping/brushing the crystal bloom off until it stops... Then
you know the plaster is dry and "cured" ready for use. You will
then be able to address the other "design faults". Maybe laths
across the table so air can circulated between it and the plaster
or sacrifice your table top completely by cutting out circles or
a grid of squares, leaving enough along the sides and across the
centre to take the weight of the plaster PLUS a lot of repeated
clay wedging...

BTW peroxide is a more environmentally friendly and safer way of
dealing with moulds and cleaning chores around the studio and
home. There are very few applications where it is advisable to
use pure peroxide (or bleach, if you must). Follow the
instructions in small print on the bottle... Diluted is equally
effective, but the manufacturers are not going to advertise that
fact, are they??

Sincerely

Janet Kaiser -- Taking the high road...


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