Making the master mould PT1

This blog entry will cover the steps working towards creating a master mould out of fiberglass, this part 1 entry will cover the prep and silicone pouring which will then lead onto part 2 in the next entry.

The process:

Figure 1

To prep the face cast, it is sprayed with a release agent to prevent the silicone from sticking to the cast. A release agent such as eject it mold release.

‘Eject it is a silicone-free mold release ideal for releasing silicone from patterns and silicone-to-silicone applications. It is also used for releasing resin molds when casting encapsulated prosthetics (Brick in the yard, ND)

Figure 2, 3 & 4

Mixing parts A and B, silicon Fs20 is used with a small amount of silicone dye. 3 layers are poured over the face cast at a height to prevent air bubbles. The keys are avoided, and the silicone is evenly spread across the base of the board. Silicone can be purchased from special effects retailers such as Neill’s Materials from the following link: https://www.neillsmaterials.co.uk/product/fs-20/

Figure 5 & 6

Two more layers of Fs 20 silicone are applied with added polyfiber to support the previous layers of silicone. Using this technique helps strengthen the silicone mould and reduce cost as it uses less silicone.

Washing up liquid is used to smooth the surface for easier application of fibre glass later. Polyfiber can be purchased from the following link: https://www.mbfg.co.uk/QL3862.html?gclid=Cj0KCQiAtqL-BRC0ARIsAF4K3WFZ6z_Y5cP5auXCkHn5Y36WNY5XXfOzs_vBHAUClGsojAbLwh6BlZQaAoMoEALw_wcB

Figure 7

The dried clay is removed, and the board is cleaned up ready for fibre glassing. Excess silicone is cut from the keys to neaten the mould up ready for the resin gel coat in the next blog entry.

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References:

Brick in the yard (ND) Eject it-33 mold release [Internet] https://www.brickintheyard.com/products/copy-of-eject-it-33-mold-release#:~:text=Eject%2Dit%2033%20is%20a,and%20cases%20of%2012%20cans. [Accessed 26/2/21]

Figures:

Fig 1 - (Radfelder A, 2020) Corrected core with Vaseline, York college

Fig 2 - (Radfelder A, 2020) First layer of silicone, York college

Fig 3 - (Radfelder A, 2020) Second layer of silicone, York college

Fig 4 - (Radfelder A, 2020) Third layer of silicone, York college

Fig 5 - (Radfelder A, 2020) First layer of silicone with added polyfibre, York college

Fig 6 - (Radfelder A, 2020) Second layer of silicone with added polyfibre, York college

Fig 7 - (Radfelder A, 2020) Clay removed and board cleaned up, York college