Casting The Limbs

Casting The Limbs
Below I will guide you through the process of casting your hand and forearm.

Start off with some big sheets of heavy duty cardboard and a roll of Duct Tape. (you may also use plywood and woodscrews)

Next, measure off the length of your arm, or hand depending on which type of cast you want. I will be doing the entire forearm,... if you only want or need the hand you can simply make a shorter retainer wall than shown.

Allow a minimum of about 4 inches spacing all the way around and below your hand. Fold and smack a piece of tape on to hold it ...... Now make one for the other arm.

Here I have made the 2 retainer walls, reinforced them with tape and sealed them to the base. (another sheet of cardboard for the base) Be sure to tape up all the seams inside and out, as well as a healthy tape seal around the bottom where it connects to the base. Make sure all seams are well sealed. You may also want to coat all the inner walls of the mold with a layer of Vaseline to help water proof it. I am using heavy duty water resistant board so its not necessary.

This is the Alginate. Basically the same material that a Dentist uses to make casts of your teeth. You can purchase it from Dental supply companies and some art stores. There are different grades of Alginate for different purposes.

Here you can see a test mix I did to check out the Alginate. This batch was in storage for a long time and had started to go bad,.. looks kind of like oatmeal,... and it really should look a bit more like pudding. Since I only need the general form of my hand and arm I decided to use it anyhow. If it doesn't pick up all the details it wont matter.

Now we move to a exterior location. I recommend this part be done outside due to the incredibly high mess potential. Now the Alginate is poured into the retainer wall. You want to get enough mixed up to fill the mold on the first shot as this stuff will set up in just a few minutes. (even less if its old) Mix it just as you would mix the plaster.

Now its time to stick your arm in. The arm should be coated with Vaseline ahead of time. Insert your hand slowly wiggling your fingers and hand as you put it in. (this will help any air bubbles from forming) Once your hand is in place and completely submerged, hold it as stationary as possible. Within a few minutes you should feel it setting up.

Once it has set, slowly and gently begin to move your arm to one side. You will be able to feel the Alginate pulling away from your skin. There will be a vacuum lock on your hand, so slowly begin to move your hand and fingers. Once you allow air to travel down into the alginate and release the vacuum you will be able to slide your hand out.

Here is what it looks like after you remove your arm.

Now carefully trim any excess alginate from around the lip of the cast. Do this very carefully! Do not allow any of the pieces you trim (or anything else) to fall down inside the casting. Once you finish trimming begin to mix up the plaster.

Here I am pouring the plaster into the cast. Note that the surface of the alginate stops about 3 inches from the top of the retainer wall.

As you can see I continue to pour plaster to fill beyond the surface of the alginate. This will create a nice base on the bottom of your cast. Once the plaster is poured, gently tap on the outside of the retainer walls to vibrate the cast. This will help any trapped air bubbles to rise to the surface. Allow the plaster/stone to set to full strength.

Here I have gently turned the casts upside down and removed the retainer walls.

Now carefully cut away the alginate from around the stone.

Here is the finished casting. Since the Alginate was super old I lost much of the fine detail, but it will work just fine for what I'm going to do with it. If you want you can now give it a coat of paint and/or a few layers of spray sealant.

You can follow these same steps (with slight modifications) to cast your feet. Do everything the same just alter the retainer walls so that they are big enough for your foot to fit in.