Introduction: How to Make a Glowing Rainbow Foam Dragon Egg

About: I am a mom, wife and teacher. In my spare time I make props, costumes and set pieces for local schools and theaters. In between shows I make a variety of things from jewelry to dragon eggs. I love trying new m…

This dragon egg makes a nice glowing rainbow night light. It is bright enough to see in the daytime but is more impressive in a darker environment.

I will take you through all of the steps to make your egg glow but you can always stop at the carving step and have a cool dragon egg decoration or prop.

After you have made your first egg you then have a reusable mold to make many more.

Note: This project includes the making of a silicone mold but I will not be going into the finer details of mold making.



Plastic or Foam Egg (slightly smaller than desired dragon egg size)

- Modeling clay (non-drying kind)

- Insulating Foam Sealant- gaps and cracks (a dense spray foam is recommended)

- Acetone for clean up of any foam mess or the straw nozzle. (You will use very little of the foam, so if you can reuse it then all the better.)

- Silicone mold mix

- Disposable plastic cups (regular and mini), - Stir sticks - Nitrile gloves - Mold release is not usually needed between a silicone mold and insulation foam. - Disposable paintbrush for the first layer of silicone.

- Casing for your egg mold (plastic coconut that I cut a pour hole in the top of)

- Utility knife - Spare blades. Cutting foam quickly dulls your blades. - The larger bread knife in the picture below is optional. I used it to cut the stem then I used the utility knife to carve out the hole.

- Submersible LED light (with remote is optional but handy)

- Clay shaped cutters (diamond or oval)

- Wood skewer

Optional materials - Glitter - Paint - UV resin

Step 1: Pick Your Egg

I used a 3" plastic Easter egg as my core.

I added a ring of clay, approximately 1.25" in diameter, on the bottom for a stand. This is also where your pour hole will be.

*Do NOT cut out the bottom of the egg! If you do you will have to fill it in before making the mold. Unfortunately, as you can see, I made this mistake just once.

Your finished dragon egg will be larger than the plastic core due to the clay you will be adding. Other eggs I have used are large, coated foam eggs. Either works just fine.

Step 2: Make & Apply Scales

  1. I used modeling clay. (the kind that doesn't dry out) I first flattened the clay with my acrylic roller, I then ran it through a pasta type clay roller for sheets of an even thickness.
  2. I then used polymer clay diamond cut out forms of three different sizes. The larger the egg the more variety of sizes might be needed.
  3. I first covered the egg in a thin layer of clay. It is not required but I found it helpful when attaching the scales to the egg form.
    1. My first egg, the largest, I did not cover in clay as you can see in the picture, but covering the egg in clay helped a lot in the following eggs.
    2. Beginning from the bottom of the egg, I applied the smallest diamonds in a ring. Then squished the top half of each diamond, so when I applied the next layer they laid down snugly.
    3. I roughly divided the egg into 5ths. A couple of layers of small, a couple of layers of medium, a couple of layers of large, back to medium and finished with small.
    4. Smooth any gaps between the scales with the wooden skewer.

Step 3: Make a Mold

  1. I used a platinum silicone rubber mix. There are a variety of choices but I wanted something that would set quickly. Because of the nooks between scales I wanted to avoid bubbles, so I applied the first small batch with a brush, stippling into the nooks and crannies. I then applied a several thicker coatings until about a half inch thick.
  2. To hold my mold in place I found a plastic coconut at the dollar store and poured about a half inch of mix into the bottom. After the silicone set, I placed the egg on the bottom, top down, and poured the next batch almost halfway. I then duck tapped the coconut closed and poured another batch up to the top through the hole that I had cut out earlier.
  3. After the silicone had cured, I removed the plastic and cut the mold in half with my utility knife, creating a vertical seam. Then I removed the clay egg from the mold.

Step 4: Applying the Foam

  1. I placed the silicone mold back into the plastic coconut and duck taped the seam shut. I went in multiple directions with the tape for extra support.
  2. Shake the can of foam for at least 30-120 seconds. (Follow the manufacturer's suggestions)
  3. Place the straw nozzle far into the mold. Spray in the foam about 3/4 full. I let it slowly push up the straw up out of the mold. Optional: You can put something over the opening for a few minutes to force the foam into the crevices.
  4. Let it sit for a minimum of 24 hours. It will overflow and the outer shell will feel hard, but the inside is still curing. If you have a small egg 24 hours will be long enough of a cure time. Anything larger than 4 inches thick, I would wait 48-72 hours before de-molding it. My larger eggs I demold at 48 hours but don't cut into them until after 72 hours.
  5. If you want to re-use the straw and can of foam, try cleaning them with acetone and let them dry. (This usually works but not always.)

Step 5: Carve the Foam

  1. You can use a sharp utility knife to remove any blemishes or shape/texture the scales.
  2. Carve out a recess in the base of the egg to make room for your light. I carve quite a bit out of the inside leaving about 1/2 to 3/4 of an inch to the outer wall in all directions. I used a clay tool to help scrape out the sides after cutting the foam with a blade. *I tried using a hot knife to carve the hole but it was very slow and not very effective, plus it created fumes. (Wear a respirator when carving foam with a hot knife.)

Step 6: Light the Egg

I used a submersible LED light that I had already. It has a twist on/off feature and can cycle the rainbow of colors. You can also find ones that have their own remote and can stay on one color or cycle through the rainbow of colors. *I prefer the remote so you don't have to keep removing the light to turn it on or off.

Step 7: Decorating the Egg

You have many options.

For my first egg, I chose to use ultra fine white glitter and white glue to give some sparkle and a little durability.

My second egg I went with a clear paint coat and then trimmed the edges with gold enamel model paint.

Painting your egg in anything other than clear will result in a darkened egg when lit. Brush strokes from coats of paint will show up.

If you really want some color on your egg, I suggest that you thin the paint down and apply with a sponge to avoid brush strokes.

You also could apply very thin layers of resin, something that dries quickly, like UV resin, if you wanted it more durable. If there is any pooling of resin though it will result in dark spots on your egg when lit.

*Do Not use an aerosol spray to coat your egg. The propellant will usually dissolve the foam.

Step 8: What to Do When the Foam Egg Has a Major Flaw

***One of my molds shifted and I had a huge depth change in one of the seems, so I enlarged the crack, carved it a little deeper, painted the scales first with black then a metallic color-shift purple, used watered down red alcohol ink on the inside foam, covered that with ultrafine white glitter, then trimmed the edges with gold enamel paint and decorative filler crushed mirror glass.

I wanted only the crack to glow when lit. So a major flaw became one of my favorites.

Step 9: How This Came About

I hope you enjoyed this instructable.

I saw a video of someone making a GOT dragon egg and was bummed that it didn't glow, so I decided to make one. When I posted my first egg to my friends and family (GOT and dragon buffs) they were super excited. So I made three eggs molds of different sizes and have been playing with different ways of decorating them. One friend wants one for her Halloween costume. A couple more of my friends asked me to make an instructable for it so here we are.

I am an Art teacher and in my spare time, I make props, costumes, set pieces for the local schools and theatres.

I look forward to seeing the eggs that others make from this. Please post your questions and finished products.

Have fun!

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