If you have the weird twisted fantasy of having people sucking on your fingers, this is the perfect instructable for you. I'm making candies in the shape of my own fingers, so people can suck or lick or bite my fingers. And it'll be "finger licking good", in the most literal way!
Step 1: Introduction to Life Casting
Lifecasting is fun and easy. The most important thing to consider is the purpose of your casting, for example, do you want to do a single cast, or multiple casts, and are you casting in special materials, such as food materials.
In our case, we're making finger candies. So whatever mold we make, it needs to be food safe. Also we want to be able to cast multiple times, so we can have tons of fingers in the end. (of course!)
The Equinox® Series from Smooth-on , a food safe silicone putty will be the most ideal in this case. It's super easy to work with: basically wrap the material around your fingers (or anything) and then you have a durable mold that gives you great details.
However in this instructable I'm taking a detour since I want to use materials I already have. There're always many different approaches to cast something, so I'm enjoying the experimenting process. Although it's definitely a bit of an overkill for this application, it might give you inspirations on your other projects since it involves several casting materials.
Step 2: Alginate Mold for Your Fingers
First I used alginate to cast my fingers.
Alginate is a super cheap and easy to use life casting material. The only downside is that it's super fragile thus can only cast once. It sets in 10-15 minutes, so it's not too painful for us to hold our body parts in a still position. Follow the instructions for mixing alginate and water, usually it's about 1~1.5 to 1 by volume for alginate powder and water. Use your hand to mix until it's consistent without lumps.
Prepare your casting containers beforehand. I used paper cups and trimed the lips so that it's easier to stick my fingers in. Once you're done mixing, stick your fingers into the mixture, make sure they don't touch each other or the bottom/wall of the container.
In 10-15minutes the alginate will set and you will feel it. (You can raise the whole container up with your fingers!)
Carefully pull your fingers out of the container. Remember that alginate is super fragile and easy to break so be super careful to keep the alginate intact.
Step 3: Cast Fingers in Epoxy Resin
Now with the alginate mold we can cast our fingers in a more durable material. Why do we need a more durable version of our fingers instead of using our fingers directly? Well it's cause our human flesh won't stand a lot of casting materials (both in terms of contact allergy and curing time) so to have a more durable version of our fingers will just come in handy.
Here I used epoxy resin. It's toxic and can give you very bad allergy, so make sure you're well protected while working with it. Sure epoxy resin is not the only material you can use. You can use any material as long as it doesn't react to the mold itself.
At the end of this step you should have some fake fingers!
Step 4: Prepare for Silicone Mold Casting
Now it's time to make some durable food safe silicone mold for finger candies!
To save material and space I designed a box to hold all the fingers at the same time. The fingers are sanded to have a flat surface on the bottom and then hot-glued onto the bottom of the box. Assemble the box and then spray some mold release.
Step 5: Silicone Mold for Fingers
The silicone material I used is Smooth-on Sorta Clear 40. It's food safe and translucent which helps with casting visibility. Mix A and B according to instructions, and use a vacuum chamber to degas the silicone mixture. The result should be consistent and bubble-free. Pour the silicone mixture into the box slowly and if you get more air bubbles in the process, you can always put the whole box into the vacuum chamber for further degassing.
Sorta Clear 40 takes about 16 hours to cure in room temperature. Once cured, clean the edges and cut the mold open (not all the way) to get the fingers out using a scalpel.
To know more about silicone casting in general, pls go to this instructable.
Step 6: Cast Finger Candies
Now we have the final molds ready and we can finally cast some candies.
I used this candy material for dummies called "Candy Melts". The instructions are very straightforward it melts in minutes with a microwave. I added some coconut oil in it so it flows better.
Pour the candy mixture into the molds. Tap the sides and bottom of the molds to make sure the candy fills all the way inside of the molds. Put the molds with candy mixture into the fridge. The candy will fully harden in 10-15 minutes.
Step 7: Let People Suck Your Fingers!
This is the most important step of this instructable! Have people suck your fingers! But be prepared to become uncomfortable yourself to see people do weird things with your fingers......I warned you!