Fetal Deep One Moldmaking and Casting 04

So last time, we left with everything setup to do the second side.

The second side of the limb molds and the main mold were poured. The main mold being two separate pours with the second pour having a thickener added to the silicone. These were left overnight to cure.

limbsecondsidepour mainmoldsecondside


The main mold was then prepped with a retaining wall for the second side of the mother mold. Real important here: generous vaseline on the mother mold surface (pale yellow area) that can be seen buried in the clay. If you don’t, when the two parts meet and cure, they will become one. Your silicone mold and model will be trapped inside. And that is the way they will be forever unless plied with some tool of destruction.


The mother mold material applied and then the resulting mother mold shell out of the clay matrix.

secondsidemother mothermold02 mothermold01


So, now all is  done. Here are the molds, open and ready for casting. I did not grease the silicone surfaces so i had a bit struggle to separate them as it had setup overnight. I usually pull these apart after three or four hours without difficulty. The longer the two surfaces stay in contact, the stronger the bond between the silicone halves becomes. When anyone tells me that silicone won’t stick to itself, I just grin and nod. In truth, I should grease just as a matter of good work protocols.

limbmoldfin mainmoldfin

Initial test castings.

limbcast mainmoldcast

For my needs, the castings are quite successful. From here, the work flow becomes cleanup, adding parts, finish work, painting and mounting. The main figure will serve as a base to which more fins, gills etc. will be added by hand to each individual sculpture. These parts will be created with apoxie sculpt as i go along. Given material costs and time frames, some things are just easier to create by hand than to cast. The limbs will be glued into their appropriate holes and blended to the body. I am now roughly one third complete with this project.

If you have any questions regarding this process, feel free to contact me.