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recuperate greenware cracks

updated sat 3 jan 98

 

Fabienne on thu 1 jan 98

Hello everyone,

I handbuilt approx. a 30x15 inches soft slab piece with a coil around it.
I was extremely careful while piecing the coil and slab together
(scoring/slipping), and it's been over a month that I am _slowly_ drying it
just to make sure it doesn't crack, but I just found 2 small fissures :( I
am not ready to give up, I was wondering if there is a way to save it
besides what I am currently attempting to do. I am patiently trying to
brush some slip in the crack, let it dry, and sand it, then start over
hoping it will eventually fill up.

TIA

Faye [Newbie and Greenie]

Laura Conley on fri 2 jan 98

This technique may still help now, but mostly it is preventative: After
attaching two pieces, the connection and some of the clay surrounding it can be
covered with wax. This allows the additional moisture from the slip to
gradually move into the surrounding clay, evening the moisture content of both
side pieces, instead of simply evaporating. Some people have complained that
this wax doesn't completely burn off during the bisque firing and may cause
problems in glazing. I have used this method many times and have had no
problems. The only problem I could imagine is that there is some slight
discoloration which might show through under a clear glaze.

Best of Luck
Laura Conley
Boulder, CO