There are a lot of reasons why we wanted to make a zombie hand, not the least of which was because it will be Halloween soon. We also wanted to try our hand at lifecasting and working with plaster and alignate. There were flaws in both the mold and the casting, but it was great for a first go and our little mistake actually made the fingers kind of look like they were severed. We hope you enjoy.
Make sure you watch the video, as it shows a bit more of each of the steps.
Step 1: Making the Box for the Mold
The first thing we did was create a box out of MDF/Hardboard that would leave about a 1" border around Amy's arm. This was assembled using hot glue to fasten it and then hot glue was ran around all of the outside edges to help seal it so it wouldn't leak.
Step 2: Mixing the Alginate
We used alginate to make the mold. This particular alginate is from a company called Skullduggery. We picked this up at Hobby Lobby. It gets mixed 2:1, water to powder. It's fairly simple to use and the main thing is to make sure you get all of the large clumps of material out before you pour it into the box or container. Small clumps are okay... or so it reads on the bag.
Step 3: Molding the Hand
We poured the alginate mixture into the box and then tapped it a few times on the table to bring some of the bubbles to the surface. Then, Amy dipped her hand/arm in a few times to get it wet and then stuck it in and held it. Amazingly, this mold sets up in about 5 minutes.
Once it has hardened, which Amy said you can feel happening, then you can pull your hand out. There was some suction, but wiggling her fingers and firmly pulling allowed her to release her hand.
There really were no instructions on how long to wait before casting in the mold, so we waited 30 minutes.
Step 4: Mixing & Pouring the Plaster
We also used a plaster from the same company for this project. We figured that they would probably play better together that way. Anyway, the plaster gets mixed in 1 lb. to 11 ounce ratio. 1 lb of plaster to 11 ounces of water. It mixes well and pretty fast. Once it is mixed you can pour it into the mold.
NOTE - tipping and turning the mold about half way through the pour may be beneficial. We had some voids on the bottom of the fingers where the plaster must have created air pockets.
Step 5: Unmolding the Casting
We were going to try to pull the hand out and make another casting, but we weren't sure if that would damage the casting, so we just broke apart the mold. It came out well and very detailed, with the exception of the voids on the fingers. We let this dry for 24 hours per the instructions.
Step 6: Bracing the Hand
The hand was hot glued to a piece of scrap wood. Simple enough, though you might have to work at getting it to stick and sealing the edge where the two pieces meet.
Step 7: Painting Aka Zombifying
Painting was, well... painting. We just tried to use some "dirty" and "bloody" colors and give the piece an overall greyish dead look. Perhaps using an airbrush would have yielded better results, but that is something we lack. You can see the painting process a little better in the video.
Step 8: All Done!
That's it. Not necessarily the easiest of projects, but it is definitely doable. After we were done we slapped it in a bowl and buried it with delicious candy.
We did learn a lot from messing with the alginate. The plaster is pretty basic and works just like you would think it would. The alginate definitely begs some use in future projects. That stuff is really cool.
We hope you enjoyed this DIY project and the video that goes along with it. If you have any questions or comments please let us know, we'd be more than happy to help you out. Thanks for checking out this Instructable.