CASTING
Two-Part Silicone Rubber Mold & Resin Cast
Overview
An individual graduate course project to duplicate an item with personal value. I chose a Chinese-style temple (a rook) piece from a chess set I received as a gift from my aunt. This was a chess set that was used on a handful of occasions when my Dad and I wanted to feel like we were playing a more serious game of chess.
The original plastic pieces were made to imitate dark-red wood and jade. The liquid plastic resin copy would be an ivory color.
Details
Tools & Processes: silicone rubber casting / rapid prototyping
Outcome
I was able to create multiple plastic castings of the original chess piece with minimal blemishes. This prototyping technique has been added to my toolkit and proved useful for creating multiple models, especially if paired with uniquely crafted clay models.
Casting Plan
This casting project had a total of three major sections: Creating the first half of the mold, then the mold's second half, and finally pouring the liquid plastic in to form the piece.
Calculations to determine dimensions of the casting container and volume of my piece were completed. The parting line (where the two halves of the mold separate) I decided upon was diagonal so it could be hidden and allow the mold to be easy to separate.
Building the Mold Container
The majority of the mold-making process involved preparation for pouring the silicone rubber. See process photos below.
Container dimensions for pouring mold
Pouring the mold mixture
Second Half & Final Mold
Once the first half of the mold was set, the second half of the mold was created. The mold container was rebuilt, maintaining the position of the syringe.
The Castings
The volumetric amount of liquid plastic that was previously calculated was mixed and poured carefully into the mold through the syringe. Multiple iterations were poured to reduce the micro-bubbles and blemishes.
The Casting Results
The detail of the chess piece, including the bricks and the roofs, turned out very well. The parting line is nearly invisible.
Note that the original chess piece is slanted, as well - the castings did not warp.
Conclusions
The most important takeaway from this project was that spending time in the beginning during the setup will save you time in the end. Taking the extra time and effort to take off the stray clay pieces during the second half of the mold was well worth it for a crisp casting result.