Introduction: Laying Your Own Eggs, So to Speak

About: Driven to make crazy ideas real.

Now's your chance to make that decoritive egg you have always wanted to make. All that has held you back has been the mold with which to cast your fake egg wonder.  No longer.

In this Instructable we will build the perfect, and low cost egg mold. Within but a few short hours you will be laying eggs made of any material you choose.  Make the obvious choclate egg, wax candle eggs, soap eggs, or even paster eggs to fill all of your eggcentric decoritive needs.  Anything that goes from a liquid to a solid state can be yours in the shape of an egg.

Are you still with me here? Then let's go...

Step 1: Gathering Materials & Tools

Let's gather a few materials and tools. This is a fairly simple project so you should have everything on hand except perhaps the casting plaster.
  • One empty milk carton - 1quart / litre (plastic can work too)
  • One large egg
  • Casting plaster
  • Water
  • Cardstock or heavy paper
  • Tape

  • Ruler
  • Pen
  • Knife or scissors
  • Bowl for mixing plaster (missing in the photo)
  • Spoon for mixing plaster, or drill mixer
  • Gloves and dust mask for work with plaster

Step 2: The Magical Egg Mold

The mold can be any empty container about the size of a one quart/litre milk carton.  The idea is for it to have a solid and sealed bottom so that wet plaster doesn't seep out when poured.  There should be at least 3/4 of an inch between the egg, standing on end, and the sides of the container. Here I am using a 1 litre milk carton that I have washed out.

First, let's take our ruler and measure 4 inches from the bottom and mark with our pen.  This is where we are going to cut. If you like you can mark a cut line around the container, or if brave you can free cut.

Once cut you may find the container wobbles some.  This can be fixed with some plasticine, play-doh, what-ever, on the corners to stabilize it.

Now, let's draw a line around the widest part of the egg. Your line will look much better than mine.

Next, we need to make a small tube using some cardstock, or other like material.  The easiest way may be to roll the paper around something like a fat pen or AA battery.  Once rolled tape it and set aside for use in Step 5.  See photos.

Step 3: Mixing the Plaster

OK, we are now at the part where you realize this project is too much trouble. Or not.

If you have experience mixing plaster then you can skip this step worth of instructions.  Just mix the way you are comfortable, but do measure the water needed before mixing.  An easy way to figure out water requirements is given below.

To measure the water required take the milk carton, our mold, and place the egg in it.  Now fill with water to approximately one half-inch from the rim.  See first photo. This is the exact amount of water needed.  Take the egg out and put it somewhere safe.

If you are mixing your plaster and water by weight, as described below, then place an empty container on a kitchen scale, zero it, and pour all the water in it. Write down this number.

Plaster is often mixed at a ratio of 65 parts water to 100 parts plaster by weight. So, to figure out required plaster just divide your water weight by 0.65 and write this number down also. See photo showing my math. My example uses metric weights, however imperial weights work just the same, your numbers will just be smaller.

Final math note, then straight to mixing.  You now need to divide your water and plaster evenly in two as we will be pouring twice with time between each.

Now for mixing. Have your water in the container you want to mix in.  Add the plaster to the water ensuring plaster is submerged.  Let it soak for a minute, then mix. With small batches like this using a spoon or paint mixing stick is just fine.  I'm using a small mixing tool because one, I made it, and two because I tend to be lazy  efficient.  

The mixing tool shown in the drill in photo 5 is from my Instructable called Plaster Mixer - Made Easy, Easily Made.

Step 4: Pouring the Mold Bottom

This step is easy.

Pour the entire mix in the mold. Knock the mold against the table a few times to even it out and help release trapped air.  When the plaster starts to get thick, place the egg in the centre.  For candles place with the bottom down. Place the egg top down for all other castings.  Only push as far as the mark we made on the egg.  This will leave a small ridge around the egg, and that's what we want.

Take a half-hour break then move to the next step.

Step 5: Pouring the Mold Top

Next we pour the top of the mold.  This is the easiest part.  Wait, wasn't the last step the easiest?  Well, you be the judge.

Repeat Step 3 where we mixed the plaster.

Get that tube like thing we made in Step 2 and hold it on top of the egg as shown in the photo.  Once you have the tube held comfortably and securely pour the plaster in the mold.  Ensure the liquid plaster flows to all sides as evenly as you can.  It doesn't have to be absolutely perfect.

Now, take another 30 minute break while the plaster sets.

Step 6: Final Step

The plaster may still feel damp, and maybe even warm. That's OK.

Grab the paper tube and twist.  It should come out easily.

Cut the container off.  If the two parts don't easily separate then let your mold dry some more.  Say, another half-hour. If you are as impatient as I then you will at this stage take a flat blade screwdriver and a small hammer.  Place the screwdriver in the crack between halves and lightly tap. Or let it dry some more.

Now, while it is still damp you can clean up edges with your knife.  Furrow out the opening where the tube was to make a small funnel.  This is where you will pour whatever materials you are casting.  See photo.

Step 7: Bonus: Casting Ideas

Cast anything. Seriously. Results may vary but the important thing is having fun.

I cast a wax candle, plaster, and glycerin soap.  The soap didn't turn out so well. I read that you can slowly melt glycerin soap in the microwave. My soap must have had some weird additive because the photo below that looks like cotton candy, well, that was my soap. It blew into this big pink bubble and then fell flat.  Smelled nice at least.

For chocolate just line each side with foil and cast without putting the mold together.  Clean up each side when hardened and fuse together with heat.

For plaster be sure to use a release compound on the sides or the new plaster can fuse to the mold.  Also, I recommend pouring the bottom then right away put the top mold piece on and pour the rest.  This is because it can be hard to get plaster to all parts of the egg, so this just helps you part of the way.  Also, you may have to add plaster as the stuff you poured dries as it tends to leave a void in the centre.

Clay would work well too.  Just mix with water to create a slurry and pour.  This will leave a hollow void just as the plaster does, however this may be a plus.

There.  That's it. You don't even need big bunny ears to do this.

Post in the comments what you have cast, especially if strange.

Now go have fun.