Expert: Sam Kelly - 3/26/2009

Question
I am sure you have answered this before, so I apologize in advance if I might be forcing you to repeat yourself.  I know I checked, but I couldn't find something that was similar to my situation.  I am by no means an expert at this, but I do enjoy doing ceramics in my spare time.  However, I do them at a small studio near my house and they keep screwing up pieces that I have spent a ridiculous amount of hours working on.  I'm including a picture to show what I do.  But even when I feel I'm doing everything right it still bubbles and pops through the glaze.  The studio uses Gare underglazes, I don't know what they use to clear glaze them with I would imagine it's the same brand.  My pieces come out with spots that didn't get coated and still feel like bare bisque, spots where the glaze has bubbled up and popped a hole in the clear, and sometimes there are even some places where colors that were touching when I got done painting are no longer doing so when I get my fired piece back (to the point that bare bisque is showing between colors)  Do you have any advice?  Is there something I could be doing to prevent this?  I sand the entire piece of bisque before I use my carbon paper to transfer my basic images to my piece. (I've found it makes the bisque smoother to transfer the image onto as well as to paint on) Then I do 2 to 4 thin coats of underglaze on each tiny little detail.

Answer
hi Amber, if the pic of the plate with the Peacock on it was yours it looked good, however it was only a very small image, not much bigger than a postage stamp.

Your problem is with the glaze if you are applying on bisqued pots with underglaze matured on the pot during the bisque process, yes I have seen it before and it was the glaze composition that was the problem, problem being the firing was the wrong temperature for the glaze.

one thing that must be always done is apply the underglaze/anything to the bone dry pot, AND THEN bisque. A lot of glazes will not perform properly on underglazes applied to bisque, glazed over, and fired, it peels back like a volcano crater.

never use sandpaper to clean up a bone dry pot, use a fine scouring pad that is used in the sink while doing the washing up of the dinner plates.

keep me informed, sam