MOLDING AND CASTING!
Molding and casting project explores prototyping an object and brings possibilities of having designed object to a near-production level of prototyping. An object chosen for this experimentation is Minion toy from my little brother's toy box. I thought I could use it to produce more toy figures for him to play with since Minion is one of his favorite character figures. This Minion figure has the general shape of the Minion character even without the colors and I think it generates a unique shape.
INITIAL SKETCH & IMAGE
The dimensions of the object are needed to calculate the volume of the object as well as the volume of the proposed mold. The volume of the Minion object is about 20 cubic inches and initially, the volume of the mold was calculated to be about 58 cubic inches, but after some feedback, it was increased to about 115 cubic inches. The parting line is in the middle of the object.
MOLD MAKING (1ST TRY)
Using clay, the object was placed on top of the foam core and embedded inside it for the bottom half. Four bounding walls were made to create boundary for the silicone mold. For the silicone to not stick to the object, I sprayed hairspray on top.
The mold was successfully made but i made the mistake of not making the registry holes so I cut some out with an exacto knife.
I attached the syringe and two smaller tubes on the object and made the second half of the mold. Here i also made the mistake of not spraying the hairspray so the result of the mold was one big block of silicone. So i had to cut the mold in half to open it up and take the Minion figure out for the second try.
The result was that two halves of the mold were stuck together.
MOLD MAKING (2ND TRY)
Re-do of mold making starting with the object embedded in clay. Ready for silicone to be poured in.
This time I remembered to mark the registry hole before I put the silicone mold in for the first half.
The holes in the back of the object were covered by hot glue. I attached the syringe and two smaller tubes again. I also remembered to put hairspray on before I poured the second half of the silicone mold.
Even when I put hairspray on before the second half the mold, the silicone was stuck together again. I cut the edges of the halfline mark on the block of silicone and started to rip it apart hoping it opens up exactly where I made half and half molds. Fortunately it came very close to that so I went ahead to fill the object void with liquid plastic.
CASTING (1ST TRY)
First try in casting came out only two-thirds of the object. It seems like liquid plastic didn't fill up all the way also because it was curing really fast compared to the amount that was poured in through the syringe. There are also issues with not having a vent hole closer to top of the mold which could be another reason the liquid plastic didn't fill up all the way.
CASTING (2ND TRY)
For the second try for casting, I added one more vent hole to accommodate for the large void that was created in the first try. Second cast came out better than the first, but it still didn't fill up all the way and has two voids as well as bubbles.
CASTING (3RD TRY)
Third try in casting came out the best out of three trys. I added two more vent holes where there were voids for the second cast and it filled up all the way. However, there seemed to be more bubbles as I add more vent holes.