BAMS – Medal project – Casting fingersPosted: November 2, 2014
While I have been prototyping my medal designs by sculpting them in plasticine, the intention has always been for the final medal to be a cast of my own fingers. In order to make a silicone mould of my fingers, I need to go through the process of making an alginate mould, in order to make a plaster positive, which I can then cast using silicone. The reason I can’t cast my hands directly from silicone as I would with any other object, is because silicone takes 24 hours to set and so it isn’t possible to hold my hand still for that amount of time.
Mix the alginate powder with water, for this powder I used 3 parts water to one part powder, but this may be different for different brands of powder so make sure to check on your packaging if you’re mixing alginate.
After 15 minutes the alginate will have set, and it is now ready to pour plaster into. However the main issue with alginate is that it can dry out and shrink, so it is important to try and keep it damp or submerged in water when possible to get as many uses out of it before it deforms.
From this plaster positive, I can then made the silicone mould
To see the wax positives I made once the silicone had set, click here