Introduction: Crayon Terrazzo: How to Make Better Art With Science!

About: DIY and Making-Wood, Glass and More!

Have you ever had the greatest idea - that just didn't work out? Did you give up after the first try? I have had the idea for "Crayon Terrazzo" for a long time, but it took several attempts before I could get it to work the way I wanted. Follow along with this Instructable and you just might get the itch to melt some crayons differently.

In this Instructable, we'll explore the scientific method and see if it helps us make better Art with a Capital "A". You can skip the science and get right to the Instructable in step 2, but it might not turn out the way you expected! SO! as a primer, the steps in the Scientific method are:

Why?- Why do you want to do this? What do you want to learn/achieve?

Research- Learn as much as you can about what you are attempting.

Hypothesis- Try to predict what will happen when you try "the thing"

Experiment- This is the best part, where you get to try things!

Analysis and Conclusion- Check your data and see if your hypothesis was correct. If not- why? What went wrong? What can you do differently?


For the basic concept behind this project you need Crayons, a mold, and an Oven- that's it!

If you want to re-create what I made- here is what you need:

  • Glass
  • Crayons
  • Strong Line (thin wire used to reinforce stained glass)
  • Pliers (to cut/bend wire)
  • Clear gorilla glue
  • Dremel (to etch the glass)
  • Soldering supplies (To create the frame around the glass and attach the hanging hooks)
  • Medicine dropper (to measure how much water/melted crayon will fit in a given space)
  • Razor blades (to clean dried glue off the glass)
  • Straw (to blow designs into the melted crayon)

Step 1: Let's Talk Science!

Some of the things I had to know/learn about for this experiment were (in no particular order):

  • Temperature/ States of Matter- At what temperature do crayons melt? What materials should I use?
  • Flash Point - At what temperature will certain materials light on fire?
  • Material Safety Data Sheets (MSDS) - Is this material safe to heat up past 150 degrees F?
  • Viscosity - Is this going to leak? Will it be easily manipulated?
  • Volume and Displacement (Eureka!) How much crayon do I need? Will it look better thick or thinner?
  • Buoyancy - Is this material going to float? Will the pigment separate from the wax?
  • Adhesives and Applications (check out this Instructables class on adhesives) Will this glue this to that? Will it break down in the oven? Is this gap filling to seal voids?

In short...this project would not have come together without knowing some good science!

The first experiment I did was to put a crayon in my car to see if it would melt...The weather was changing and it "only" got to 90 degrees F. that day- not enough to melt the crayon in my car windshield. I then moved it next to the BBQ while I cooked dinner 'cause you know...and at 150 degrees F. it started to get shiny and soft and broke apart when I touched it.

That was enough to know to get started...

Step 2: Crayon Melt 1.0

My first experiment was something I like to call a "successful failure". It didn't work perfectly, but that first attempt helped me learn enough to get even closer on subsequent attempts. The idea behind this is to melt crayons on the back side of a cheap dollar store frame.

I had seen many crayon melting projects that used a heat gun or hair dryer to melt the crayon and move it around or fling the droplets. I thought that I could chop the crayon into tiny pieces and that would speed up the melting process and I'd get a more even coating.

Well now! What ended up happening was as soon as I turned on the heat gun the force of the air blew half my shavings right off the glass. Strike one.

To get the pieces to melt I had to use a plumbing torch, that ended up being way too hot for the cheaper/thinner glass. The crayons melted without blowing away...but I cracked the glass. Strike two.

Looked nice in the window though....

Step 3: Crayon Melt 2.0

AHA! With a little bit of experimentations and hypothesizing we moved to attempt #2.

In this attempt I used another frame with glass that was a bit thicker. I put silicone around the edges and bent some strong line wire into a nice shape and used gorilla glue to glue that down onto the glass. My thought was that this would keep the crayon colors separate.

I put this in the oven cold and tuned on the temperature to 250 degrees F. Within a few minutes the crayons were almost completely melted. This heat was so much that it became very viscous and some of it escaped through the edge of the glass out the front. I didn't check to make sure my silicone seal was water tight.

I learned that I needed to test and make sure the frame could hold water. If it could hold water with no leaks, it would be able to hold all the crayon without leaks. The part that worked surprisingly well was the metal wire separating the colors. Just like the metal strip separating floor sections in Terrazzo...we're officially ON TO SOMETHING HERE.

Step 4: Lessons Learned in the First Crayon Melts

Let's sum up some of the lessons learned so far in our experiment.

  1. Crayons start to melt around 150 degrees F. 200 degrees F. seems to be a sweet spot. Any hotter and it's too quick.
  2. Putting them in the oven cold and starting the oven adds too much heat too soon...we need to pre-heat the oven.
  3. Using a plumbing torch is too aggressive and can crack the glass and burn the frame.
  4. If the piece is not LEVEL- crayon will spill out the sides and be uneven.
  5. If the piece is not sealed the melted crayon will leak.
  6. Cheaper crayons have more wax and less pigment. If you want nicer color, you need nicer crayons (any kid could have told me this)
  7. Chopping the crayon into tiny pieces will NOT work with a heat gun or blow dryer. It will- however, work for the oven!
  8. A thin layer of crayon will let light shine through like faux Stained Glass! It's quite translucent.
  9. All materials used so far are safe to put in the oven at 200 degrees F. No noxious chemical reactions or fumes.
  10. All silicones and adhesives used so far will stay put and not be ruined in the oven.

Step 5: Crayon Melt 3.0 - Prepping to Melt

Now that we have the first two experiments done, I feel confident enough to make something exciting. I have 3 kids, and love to see their little hand prints. Every school craft is some variation of their hand traced and turned into a turkey or flower or __insert your favorite thing here___.

The only problem with these crafts is they are made with kid glue and paper. I wanted something more permanent. I had my kids trace their hands and then sign their name. I placed these underneath a piece of glass and traced the outline with sharpie. This will do two things: 1) I can etch their signatures onto the glass following their actual signature and 2) I can wet the glass in just the right spot to glue on the wire hands (something clear Gorilla Glue states you should do with glass)

Next I took strong line (a thin wire used to reinforce stained glass) and bent it into the shape of their hands, using their traced hands as a pattern. This will create a cavity that the crayon can melt inside. I put a bead of clear Gorilla glue on the bottom of the wire and weighed it down with pieces of old cutting board and water bottles. This made sure that the wire was glued to the glass tight. I soldered a frame around the glass and added hooks to both sides to hang it when completed.

I used a razor blade to clean the excess glue around the edges of the wire. I then put water inside the hand to make sure no crayon would escape when I put it in the oven. All three hands had one or two areas that needed a little more glue to ensure they were water tight.

I fill the etched areas with sharpie and wipe away the excess with window cleaner. The resulting line (engraved, filled with sharpie ink) is very crisp and you can get really detailed. You can even choose to fill the engraved areas with colored sharpie instead of black. Just know that after about a year, the colored sharpie ink will fade a little.

Step 6: Crayon Melt 3.0 - the Meltening Masterpiece!

My wife chose the colors for the hands and into the oven they went! We broke them into small pieces and made sure we didn't have too much, we didn't want it to overflow! Adding water to test if the hands were watertight allowed me to calculate just how much crayon we would need- more science! This time I pre-heated the oven to 200 degrees F. and made sure it was level. The crayons took between 15-20 minutes to liquify. Once they were melted, we used a straw to blow spiral patterns into the crayon and mix the colors.

After the crayon was solidified again, I used a razor blade to clean any crayon that spilled out or excess glue around the edges. I then cleaned the glass with glass cleaner and this art was ready to hang!

Step 7: Some Parting Thoughts

Not all the projects I work on turn out just the way I had hoped, sometimes it's worse, sometimes it's better!

I have come to realize that the more you understand the properties and constraints of the materials you are working with, the better Art you can create.

I have had these crayon creations sitting in my window. It's HOT in San Antonio, Texas...and guess what? None of them have melted. After my experiments, I'm confident that even the thin layer I have on the glass will not melt in a typical house window. A thick layer with crayon produces bright, smooth colors. A thin layer is translucent and looks great hung in a window- kind of like Stained Glass.

I hope this project has inspired you to try something that didn't work out the first time, maybe the second or third time you'll get it. Maybe there is something else you need to learn about....or maybe you just need to put some crayons in the oven.

Back to Basics Contest

Runner Up in the
Back to Basics Contest