Friday, March 11, 2011

the dreaded s-crack

see that horrible, unwelcome curved line inside the foot-ring?
It's called an s-crack (even though it is more of a "c" in this case).The photo above shows what sometimes happens to the inside foot of a bowl thrown off the hump. There is plenty of advice in pottery books and online about how to avoid this (clay body, compression techniques, trimming tricks, etc). And yet...
ready to attack the problem
I can sometimes save the piece by burnishing the crack firmly with a hardwood stick.
firm pressure with the crack, across the crack, and around and around
looks pretty good, neh?
Oh, but I won't stop here. No I won't.
adding paperclay 
I don't trust burnishing alone. I prepare a slurry of dry clay mixed with paper pulp and a water/vinegar mix for crack repair. I smear it over the burnished crack with a stiff brush.
perfect
Now, I have to see if it makes it through the bisque and glaze firings intact. Sometimes it does and sometimes it doesn't. Stay tuned.

Drowning beautiful, so incredible!