Introduction: Saran S - Casting Plaster Pencil Holder
In this Instructables, You will learn how to make a pencil holder out of plaster cast.
Step 1: Gather Materials
You will need Sizzors, a pen or pencil, a ruler or set squares, an Exacto knife, a compass, a sheet of Polypropylene, a bucket, a spatula, plaster powder, water, and 2 cups
Step 2: Drawing Out the Mold on the Polypropylene
With a pen or pencil and a set square/ruler, draw 6 rectangles on the Polypropylene. The lengths of the rectangles are 15 cm and the widths are 8 cm.
Step 3: Drawing the Bottom for the Mold
In the mold, you will need a bottom to hold the cast but no top to pour the plaster cast into it. The shape of the bottom is a hexagon. Get the compass and measure the distance between the point and the pencil. Make sure the length between the point and pencil is 8 cm as that is the length of the sides of the hexagon. Starting anywhere on the sheet of Polypropylene, draw a circle. Then starting anywhere from the circle, but the point of the compass on the line and draw an intersecting curve line on the circle. Next, put the point of the compass on the intersection between the curved line and the circle and do the same thing. repeat this going clockwise until you can't put any more lines. Then, turn the compass around and do the same thing but counterclockwise. After that, use the ruler and connect each intersection point and draw a hexagon.
Step 4: Drawing Out the Core
Next, you need to draw the hexagonal prism core. Draw 6 rectangles with a length of 12 cm and a width of 5 cm for all. Then repeat step 3 but instead of the length between the point and the pencil of the compass being 8 cm, you want to change it to 5 cm.
Step 5: Cutting Out All the Pieces
This step is simple. Just take the Exacto knife and cut out all the pieces. Once you've done that, we will be ready to put the pieces together!
Step 6: Taping the Pieces Together
For the mold, tape all the rectangular pieces to each side of the hexagon bottom. Then, fold the rectangles up to create a hexagonal prism. Tape the rectangles together and that's it. repeat the same steps for the core except for this time when you're done taping the rectangle together, tape the top hexagon on top of it. MAKE SURE YOU PUT A LOT OF TAPE SO THE PLASTER DOESN'T LEAK!
Step 7: Making the Plaster Cast
You will need the bucket, spatula, and cups you got before. In order to have enough plaster cast for this mold, you will need to add 9 cups of water, and 6 cups of powder plaster into the bucket. Make sure you add the water first because then it will be easier to mix together. Once you've added the water and powder, mix it for about a minute.
Step 8: Pouring the Plaster Cast Into the Mold
Now, pour the plaster cast into the mold. Make sure that it doesn't fill up all the way because when you add the core in, it causes the plaster cast to rising, overflowing. As soon as you pour the plaster into the mold, put the core in the middle, and hold it there. But, make sure not to put the core all the way down where it's touching the bottom of the mold. Once the mold has gotten a little hard and the core is staying, wait 30 minutes for it to dry before removing the Polypropylene.
Step 9: Removing the Polypropylene
Once the Plaster cast has dried, use the Exacto knife to slowly cut the edges of the rectangle. Make sure to not go too deep as you will cut into the dried plaster cast ruining it. Once you've cut all of the rectangles, you should be able to just peel them off and take the mold out. Now it's time to remove the core. Take the Exacto knife and slowly cut around the outside of the core. After that, you should be able to grab the core and pull it out but it might take some strength. Be careful not to break the mold and damage it.
Step 10: Final Touches
After you have removed the Polypropylene, you should get sandpaper and make sure all the edges are smooth. There you go! Your very own self made Hexagonal Prism pencil holder!