Tag: silicon mold

Silicon Mold – 2nd attempt

A second attempt was made to pour a silicon mold around the shaped resin form.

The pour was not the best, and the liquid resin did not flow correctly. An ugly bumpy lump of silicon can be seen in one corner. Normally the silicon would flow and form a very flat level on each half of the mold.

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The first attempt failed when attempting to degas the liquid silicon. In the first attempt the liquid silicon immediately cast inside the vacuum chamber into a spongy foam. The silicon resin was 12 months old, and has a recommended shelf life of 6 months.

It remains to see if this 2 part mold will be able to retain the resin without leaking!

 

Casting using Mold

A casting was prepared using the silicon mold. The casting was solid resin without any internal electronics. The purpose of the casting was to check if the silicon mold would seal correctly and not spill all the resin.   Surprisingly the very irregular silicon mold did not leak!

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The Top side shows a nice consistent ability to graduate the speckled texture to the top surface of the talisman. This texture is visible along with a smooth surface finish without bubbles. The talisman is cast upside down so the texture sinks to what will be the top surface. This is useful because the texture material has sunk and does not occlude the glow above the internal LED.

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Also any bubbles rise in the inverted mold and therefore problem bubbles appear on the underside of the Talisman. The top side of the talisman is at the bottom of the silicon mold and never has bubbles sinking down there.

 

The silicon mold was not perfect and a very clear parting line is visible around the talisman. Any blemishes and inperfections will be manually sanded down.

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Hopefully a better casting of the silicon mold would result in a less visible casting line. The silicon used in this mold was past it’s expiry date by 6 months and did not flow as well as fresh silicon.

The quantity of white pigment added to this test was hastily added at the last minute and not measured correctly. The resulting intensity of the whiteness is lower that required and this test therefore looks a lot more milky rather than a quartz like white that has been achieved previously.