You will need
- Large bucket or bowl
- Measuring cups
- Wood craft sticks for stirring
- Alginate molding powder
- 2-liter plastic bottle with the top cut off
- Casting plaster
- Craft knife
- Sandpaper (100-grit)
- Acrylic Paint
- Paintbrush
- Fine-tip paint pen
- Chisel
Step 1: Scoop alginate compound into a large bucket or bowl. To cast an adult hand, you’ll need 6 cups.
Step 2: Add an equal amount of room temperature water to the alginate powder.
Step 3: Stir the ingredients together with a wood stick. Then eliminate any remaining lumps with one hand, making sure to keep the other hand clean for casting.
Step 4: Quickly pour the paste into the 2-liter bottle.
Step 5: Insert a clean hand, held in the pose that you want to cast, into the mixture. Keep your hand submerged and in position, remaining as still as possible, for 3 to 5 minutes.
Step 6: Tap the top of the alginate with your free hand to make sure it’s fully set. Once the alginate has hardened, gently wiggle your submerged hand and fingers to get them loose. Carefully remove your hand. Congratulations—you’ve just made a mold!
Step 7: Set your mold to the side and mix up some plaster according to package instructions, stirring thoroughly until smooth.
Step 8: Pour the plaster into the mold you created. Depending on the humidity, it can take 30 minutes or longer for the plaster to set.
Step 9: Once the plaster has set, tap the top to loosen, then begin cutting away the plastic bottle using a craft or utility knife. Continue cutting carefully, now through the alginate, being mindful not to cut into the plaster fingers you’ve made. Keep removing alginate until your plaster hand is revealed. If there are any air bubbles or mistakes, use extra plaster to fill in the holes.
Step 10: Let the hand dry for at least 12 hours before painting, and sand off any rough spots before you begin. You can also sand the bottom of the hand into a flat base so that it can stand upright.
Step 11: Paint the plaster with an opaque acrylic paint and let dry.
Step 12: Using a fine-tip paint pen in a contrasting color, follow a palmistry diagram to draw markings on the painted hand.
Step 13: If you want to make a flat plaster hand into a candle holder, use a small chisel or a flat clay sculpting tool to carve out a hole in the plaster to fit the candle. Work slowly, carving just a little at a time, until you’ve made a shallow well that matches the candle’s diameter.