I've gotten some work done on my next class project, though, as usual, I wish it were farther along. I have finished carving the plaster model for my largest slip cast oval to date. The model measures 15" x 9" and should shrink down to somewhere between 12 and 13 inches once it has been fired to maturity. This one is proving to be challenging primarily because of the weight of the plaster. The model its self must weight about 25 pounds and I anticipate that the mold will weight about that much once I've cut off the excess plaster from the edges. I have no idea what the mold will weigh once it's been filled with slip and I've been wondering if a fountain pump would work on slip, or perhaps a siphon or large syringe. Either way, I'm going to need some help getting this one poured, I know.
The other issue that I'm puzzling over at the moment is how to do the modifications to the model for additional molds. I am envisioning this one as a series of three or four ovals, each of which will require its own mold, where the oval is slowly "cut" open to reveal the inside. My options are to make a new plaster mold for each new model and then re-pour the model in plaster or simply carve the original model.
If I choose to make a new model for each mold, I will have to sacrifice the mold for the model as plaster expands when it solidifies so that it cannot be removed from a plaster mold. The mold must be carefully broken off of the new model, which means that I will go through a lot of plaster! The advantage with this is that I can create a void in the model by attaching a bit of plaster or clay to the inside of the mold so that I will not have to carve out the inset parts on the model, which can be rather tedious.
The alternative will be to simply carve out the voids in the original model, like I did will the oval saucer. This will limit my carving as I will need to incorporate the previous carving into the next iteration, but it will save on time and plaster. Guess I will need to puzzle over this today and then get to work on things tonight.
Well, I hope you all are having a great week!