I recently purchased the rights to a cute relief sculpted medallion of an adorable pony called "Fjillip" sculpted by my good friend, Rayvin Maddock of Khrysalis Studios.  She has already produced this piece in a limited 40 piece edition in resin up in Canada, but I got his unlimited rights to produce him in ceramics.  Here is an example of one of my porcelain casts of this lying down pony in porcelain and glazed by myself to a bay appaloosa.  Once fired to cone 6 he measures about 6 inches wide.  The piece may be displayed standing upright as shown, or laying down, or mounted on the wall, or framed, etc.

While I very often glaze these using low fire underglazes and overglazes to produce ultra realistic horse coat colors like the appaloosa above, I also like to 'art glaze' some to mid fire cone 5/6 colors that are unrealistic horse colors but are lovely all the same.  I especially like these art glazed pieces because they are much faster for me to produce, I can sell them for less, and I can use them as gifts and show awards!   With unlimited casting rights in ceramic I made a concept plaster mold to work with first, and soon I'll produce a very crisp rubber master from the resin copy I have that will allow me to quickly & easily pour as many ready to use plaster molds for slip casting as I could ever want.  That way I can produce hundreds of castings over time for years to come with ease and not have to tediously rebuild the mold making from scratch every time I need a new plaster mold of Fjillip.

 

For drippy, runny cone 5/6 glazes however, I also need glaze drip catchers!  If I don't have them my glazes can run off onto my kiln shelves, possibly ruining them and damaging the medallions when I try to chip them free!  Complex thin jewelry pendants or an oddly shaped relief sculpted pieces like this I could use balls of alumina wadding but it is too easy for the porcelain to warp and deform, or the glaze to run underneath and require a LOT of grinding to get the drips off.  So I decided to make a custom glaze catcher made to fit Fjillip precisely as I can. I may still have some glaze seep between that will need grinding off later, but hopefully not a lot.  Therefor I had to start blocking it in with oil clay to make a plaster waste mold from. 

This photo shows several jewelry cabochons I was forming for mold making that would allow me to do crystalline glaze testing on 'test tiles' that I could then utilize for making jewelry.  I can also attach them upright for vertical tests to a simple base as desired or use them flat, horizontally.  In the upper left you can see the resin casting of the Fjillip medallion I have already used to make a plaster slip casting mold from.  Here I am building up oil clay walls all the way around and am checking the fit of the resin within it.  Underneath the resin casting is a raised lower wall to act as the lip inside of the drip catcher.  Once I remove the resin cast I'm all ready to pour the plaster waste mold which I can then clean up and fine tune for the next steps.  In the case of the cabochons they can be first line production molds for casting porcelain.  I'll keep some castings as backups for making rubber master molds from later.

For the Fjillip, which I'd like a fairly precise fit for the glaze catcher, I propped the cleaned up flat plaster waste mold piece into a plastic container only slightly larger than it.  I positioned it so there was a gap all the way around and underneath so that the plaster, face down, could be slip cast in porcelain to produce a single cast.  Once carefully removed and trimmed up, you can see the fresh porcelain casting here, just below the waste plaster.

 

Now this single porcelain cast gets cleaned up.  Some of the walls are too thin and I'll need to thicken them to be consistent all the way around or they will too easily sag and collapse when fired. 

If I found that a fresh damp greenware casting were not practical to make a new plaster mold from, I could have pressed a slab of oil clay over the plaster, or oil soap the plaster and do the same with a slab of epoxy sheet of the thickness I desire.  Once it any of those materials are set enough, I can remove them carefully and reshape them until it is just right for casting a two part plaster mold.  If you prefer modling in 3D programs you can print out any of these components to make your molds from, whichever works best for you.

I've also cast a fresh porcelain of the Fjillip pony medallion.  Here, after a quick rough cleaning (I'll fine tune cleaning it up later) I can now carefully set it onto the glaze catcher casting to check the fit.  I won't bother to fine tune the fit too much right now other than needing to test it.  Is the lip high enough?  This piece being mostly horizontal rather than large and vertical, the height of the lip is probably sufficient - but I will cast a couple of these and adjust various lip heights to be sure I have one optimized for the glazes I intend to use.  It may also inform my choices on how best to make my plaster production mold for slip casting the drip trays.

Once I test fire using a few of these and have finalized my best design, a pour spout needs to be attached before I make that plaster mold so I'll be able to slip cast these drip trays for Fjillip as needed.  Or I can cut the pour spout out of the wet, soft plaster once I have poured it.  Using the half mold I have now does work but it's clunky and does not work as well as I need it to if I want to cast quite a few of these trays.

Whichever tray version I finally settle upon to use,  I don't want that casting to dry up too much before I make the plaster.   Or produce one in another material that matches the design specs I require.  I need to check it with a very soft, still wet casting of Fjillip as well so there isn't too much shrinkage on him either.  When fired I need them to match up carefully and shrink at the same rate together.  To do that I can spray both with a little water and put them into a damp box to rest until I'm all ready to pour the plaster.  I'll need to go find a suitable plastic container or build up oil clay of the right shape and size to form the containment for the plaster.

But before I do that I'll cast a few more drip trays, adjust the heights on the lips that hold up the medallion, and test fire them to decide what height is best on my final I will use to produce my mold.  Wish me luck!