Intro: How to Lifecast a Hand With Alginate
Lifecasting is making a mold of a living body. In this Instructable I make a wax casting of my hand. The overall result was impressive. The detail captured was better than I expected, with the texture of the skin being realistically captured.
Step 1: Materials and Tools
You will need the following materials and tools:
- Alginate (I used dental grade)
- Cold Water
- Container (I used 2L pop bottle)
- Stir Stick
- Drill and Mixing Auger (optional but recommended)
- Casting Material: wax, plaster, concrete, etc..
Step 2: Alginate
What makes this whole process possible is something called alginate. It is commonly used in the dental industry to make impressions of teeth. Try to get the slowest setting alginate as my first attempt I had a batch that was quick setting and I was not able to mix it with water quick enough and I ended up with a poor cast. I purchased mine from the local dental supply but you can find it online at various places like Amazon.
Step 3: Mix and Set
I did film the whole process so you can view it to see how it was done. I will try to document the written steps as well.
Follow the instructions for the alginate as each type can be different. For the type I am using, it is 1 litre of water per pound. I am using a drill and mixer to quickly mix the alginate. The colder the water the slower the alginate will set. If you are doing a large casting like I am, you want it to set slow. The stuff sets fast once mixed with water! I don't have any pics of the mixing but all I did was pour the alginate powder into the water and mix.
I mixed in a separate bucket and then poured into a 2 litre pop bottle that was a good size for my hand.
Step 4: Making the Impression
I put my hand in the mixed alginate and tried to keep it from the sides of the bottle. The alginate I am using takes about 2 minutes to set so I had to work really fast. Keep your hand still until the alginate sets to a rubbery texture.
You can now remove your hand, it took some wiggling of the fingers but eventually my hand came free. it might seem like it won't come out but take your time and it will. Don't be too rough or you will tear the alginate.
Step 5: Pouring the Mold
Get your casting material ready, I am using wax but you can use liquid stone, plaster, concrete etc...
I melted some tea lights for the wax and poured it into the alginate mold. I poured the wax into the mold then poured it out to establish a coating then filled the mold with wax and left it to cool. It will take a few hours with hot wax.
Step 6: Remove Alginate From Casting
Once your object is set, in my case the wax was hardened. I then started removing the alginate, slowly and carefully, since the fingers of my casting could easily be broken. I used a utility knife to score and then peel the alginate. It took some time but I managed to get it out with out any damage. For the really stuck alginate in the creases of the hand, I used a mixture of baking soda and water (1/4 cup per litre water) and let the hand soak for a few hours. Then I used a toothbrush to scrub at the creases.
Step 7: The Finished Wax Hand
The detailing captured by the alginate and wax of the hand is impressive. This would make a cool decorative object. Eventually I plan on using this positive wax hand and make a mold for lost wax casting.