Common Problems with Bisque-ware
This month we are going to try to cover some of the
most common problems that occur with ceramic bisque pieces.
The most common problem we are asked about is bisque
that will not take paint in spots. If you are painting with
stains you could spray the item with a few coats of
porcelain spray sealer, let dry thoroughly and then finish
painting your piece. If you are painting with under-glazes
you can sand the area lightly with a fine grade sandpaper,
this will allow the under-glaze to adhere to the item.
Another problem we find people come across when
buying bisque from auctions is that some businesses may not
have standards as high as what most of us would consider
acceptable. When this happens you receive your item that you
wanted to glaze except it is discolored in spots or it is
yellowish brown in color.
There are two possible causes for this, the first
is that your item had been stored in a damp location and
mold spores have begun to grow in spots on your piece.
Re-firing this piece will restore your item and will enable
you to glaze the piece. The second cause of this would be
that the item had been fired at too high of a temperature.
Under this scenario re-firing the item will do absolutely no
good, you really have no choice except to stain the item.