Whilst checking my shell for my latex mold on my ouroboros whilst it was drying it occurred to me i may have been a little over ambitious with the plaster, making it a little too heavy to handle. As i have six nineteen inch mirrors to work with so far & plan to purchase another six (if they are available in store) on tomorrows monthly art supply run. It is going to be handled quite a lot!. Because of part of my disabilities (week left arm due to shoulder damage) i run a higher risk of dropping it!.
As i am using a high grade sculpting plaster not basic gypsum plaster it will dry to a near ceramic hard finish & will be difficult if not time consuming to alter. So whilst the plaster was still semi-wet i decided to reduce the amount of plaster shell around the latex mold. Whilst this IS a risky thing to do with soft plaster it can be achieved if care is taken, & a sharp craft knife of course. Below is the 'new' design for the plaster outer shell.
Not perfectly round but then this is just a support for the latex mold in the end. What you are looking at here is what 'was' the back side of the support shell, which now becomes the front, or new working surface. Whilst i do not need to add any releasing agent to the latex when using plaster i will need to do so to the visible plaster surface before i can add new boxing & pour the next half of the outer support shell. As always i will be using bees wax as a releasing agent.
Normally you should wait until the first section of the plaster mold was fully dried before creating the second half. As i want 'both' halves to dry as close as possible however i am going to carry on creating this outer support shell now.
With the exception of the 'hole' in the middle i created the boxing around the first outer support shell just as before using pizza card stock & masking tape. Once again i have since poured the plaster into the boxing mold after this picture was taken. I will show the separation & demolding of the plasticine covered paper mache ouroboros in the next post.
For all this is very tough plaster when fully dried it IS after all plaster & subject to damage relatively easily especially now since i reduce the size & strength factor of the shell radically. I have had on occasion plaster molds become damaged, my fault these times not hapless family members for a change. Ordinarily so that they were unusable. However with some brief experimentation i have found that should a plaster mold be damaged in one such case split in two complete halves. You can glue the two halves together using undiluted PVA glue (Elmer's etc) the layer the reverse (back) of the plaster mold with four to six layers of telephone directory pages torn into manageable strips. If need be a small amount of plaster can be mixed up to fill in the cracks or gaps in the working surface of the repaired mold too. Or even ready made poly filler which is a paste like plaster filler if you don't want to mess with mixing small amounts of plaster for the repair(s).
I tried this using news paper but it becomes too hard & brittle. For some reason telephone directory paper & PVA glue dries to a very tough skin that is much harder to split as with new paper.