Sprig Mug With Wings

This was one of the four mugs I made last pottery session.  I’d done keyholes on the other ones, and decided to do wing sprigs on this one.  To make the wing sprigs, I used purchased scrapbooking/multimedia pieces I’d purchased commercially, and a two-part epoxy putty.

Usually I use plaster to make sprig molds for pottery. So after I made the epoxy putty negatives, I cast paraffin in the epoxy, then used the wax positives to make plaster molds.  Then I baked the plaster molds in a craft oven to melt out the wax. This was a terrible idea.  The wax permeated the plaster, making it nearly unuseable for a sprig mold.   The reason why plaster works as a sprig mold is that the wet clay shrinks when the plaster draws out the water. With the wax, the water couldn’t escape, the clay didn’t shrink, and it wouldn’t come out of the mold. I tried all kinds of pleading and finagling to get it out, and the only thing that (kinda) worked was spraying machine oil into the waxy mold. This made a lubricant that let the clay release.

Then I realized that I didn’t have to go through all the wax and plaster trouble at all, becaue the silicone mold made a great sprig mold. I push soft clay into the mold with a scraper or rib, wait a few mintues for it to harden, then score and slip the back. Because the molds are flexible, I could place them directly onto the piece. Some of these worked better than others. Some of them, the keyhole came out upside down.