The Re-making of Aragorn (Step 10)

Welcome, once again, to my "Re-making of Aragorn" series! In this installment, I am preparing the mold casings in readiness to pour my mold rubber.

In addition to predicting trapped air and making chase holes (last post), I have to consider how the final mold will be divided into two halves for easily removing the cast part from the mold. This can be tricky if you have very dynamic parts that do not seemingly have an easy half point.

I start by examining the part and then marking a seam with a bright pencil. I will later be able to see and follow this mark as I am cutting the Sculpey part from the mold.





I follow the contour of the part and try to make as simple a line as I can, because it is difficult to change directions in the rubber when cutting the mold open.












I try to avoid any fine details on the seem and to make sure that I don't trap too many difficult areas away from the seam.








I mark a base around the model to construct the walls of the mold casing. But, I notice that I don't have much wood beyond the edge of the feet with which to work. I sometimes don't think far enough ahead to plan for the mold walls.






To fix this, I overlay a cardboard base around the model with a cut-out for the model. I generously hot-glue this base to the wood and use the hot-glue to seal the corrugated paper so that rubber will not leak out of the mold casing. I then re-mark my wall pattern around the feet.












I also think ahead that I would like the mold rubber permanently labeled with the name of the part inside. For this, I use a punch labeler. I create a raised label...




...then, I push the label into some clay that I place on the model's base. This creates reversed letters in the mold and reverses back to normal in the rubber that is poured into this mold. Thus, permanently labeling my mold.



Here are some parts prepared for the molding process. Notice, that I have them embedded into some clay. This is to suspend the part off of the base (walls marked) to allow rubber to flow under the part. I'll have to remove the extra clay once the rubber has dried and do a second pour to fill those areas.










My "quick-and-dirty" mold casings are made from cardboard/bristol board, tape, and hot-glue. Mold walls are constructed of bristol board for the small parts and thick cardboard for the body. I use plastic shipping tape to seal the seams and generous ammounts of hot-glue around the wall/base to seal against leaks and glue the walls down.

On to the rubber!