Here is the sunburst glass platter from the previous post humped with clay. I used red clay with more grog to hopefully forestall any warping or cracking. I added a large foot ring. I used WD-40 for a release on the glass. It takes a lot of clay to roll out a 15 inch circle. Then picking it up and getting it on the glass plate without stretching the clay is another matter due to the weight of that much clay.
Anna mentioned making a plaster mold, but the glass foot ring has an undercut. So if I made the plaster mold the plaster would go in the undercut unless I covered the under cut somehow. Oh I could put wet clay in the undercut and fill it in temporarily. I will have to experiment with this.
I think this slumping over that foot ring may be a problem since when the clay starts to shrink the weight of the sides will not let it shrink back and up to the middle, if you see what I mean. Cindy mentioned she had problems with that. I know if I take the clay off too soon then the sides will flop and droop down. Cindy said she took her plates off and propped them with something when leather hard, I may have to do that and prop the sides with some soft foam. This is a perfect example of process of the trial and error of making new works in clay. Sometimes many pieces are made and discarded before a piece is perfected into an acceptable form.
Also the problem with using the plate as a hump mold is I'm not able to carve in any texture like the original glass plate. The bubbles in the center and the lines accentuating the rays of the sun are kind of what makes the plate sing. I may have to make a bisque plate, then use that as a mold and slump it and then I can carve it. I'm still thinking about how to work all this out. More ideas or suggestions are gladly welcome. Meanwhile I'll keep on eye on this attempt. Please keep your fingers crossed. Thanks for reading and for all your comments and suggestions.