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firing lids on vessel galleries using wadding

updated wed 22 sep 10

 

Dinah Snipes Steveni on tue 21 sep 10


Hi Terri Roy

No, wipe them clear of glaze -- I use a fine grain sponge (wetted) upholstr=
y grade cut down, large and flat glued to a batt and wipe bases and lids an=
d so forth on it -- and set the lid on the gallery rim of vessel using sma=
ll dots of wadding. Fired together you get a good seat/fit and little disto=
rtion. Stoneware and porcelain temps can cause bodies to stick together, vi=
trification, as you know that's why people put alumina hyd into the wax, bu=
t as it's been pointed out the wax is not designed as a "separators" job. U=
sing wadding to break the seal is necessary. That's my take and practice. S=
omebody in the forum has mentioned glazing entire lid and gallery rim. Mayb=
e in earthenware where you don't have to worry about distortion and can pro=
p lid and fire it separately. Hope this is useful.

Dinah

Vince Pitelka on tue 21 sep 10


Regarding Terri Roy's question about wadding lids, previous posts have =3D
already explained that you cannot glaze the gallery contact points with =3D
the lid in place, with or without wadding. Terry, I would ask you to =3D
consider the long history of glazed ceramics, and the fact that =3D
lid-seats on covered jars, covered boxes, and casseroles are usually =3D
left unglazed. If you carefully sand the unglazed clay gallery surface =3D
after the firing, it will be very smooth to the touch. From my own =3D
point of view after 40+ years of professional involvement in studio =3D
clay, a glazed gallery feels all wrong. When I put the lid into place on =
=3D
a glazed gallery, it seems vulnerable, as if it will chip easily. It =3D
makes an obnoxious "clink" sound like what happens when you bump two =3D
glazed ceramic objects against each other (which is of course exactly =3D
what is happening). A properly-done, well-fitting unglazed lid is like =3D
a ground-glass contact on laboratory equipment. It is a very satisfying =
=3D
contact and fit, and it just feels right. =3D20
- Vince

Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net; wpitelka@tntech.edu=3D20
http://iweb.tntech.edu/wpitelka