Introduction: 3D Triceratops Skull Sign

Back in June of 2007 I showed you how to make a 3D sign using the instructables logo.

In this instructable I want to step it up a bit by making every element dimensional and textured

Step 1: Cutting the Parts

I used a high density urethane foam product made by Coastal Enterprises called Precision Board.
This material is 1 inch thick and has a density of 18lbs per cubic foot. They have material ranging from 6 to over 60 lbs pcf and in thicknesses 1/2" to 12" and over. However you could just as easily use the pink or blue insulation foam found at your local hardware or home improvement store.

This photo shows my paper patterns spray glued to the foam and my jig saw ready to rip, if you have a cnc router or maybe a LASER (this probably cant be cut with a laser but this is my submission for the epilog laser), this step could be automated, you work out the details here.
I have a jig saw and a dremel, so thats what I used.

You can draw right on the board or project a pattern or, like I did, set it up in coreldraw and print out on a plotter. You can even use your laserjet or inkjet and print and tape together your patterns, use your imagination.

Step 2: Glue It Up

about an hour and I had the parts cut, glued with gorilla glue, and clamped.

Let it dry over night and your ready to shape it.

Step 3: Ready to Shape

these pictures just show the parts glued up

Step 4: Shaping the Skull

I didn't get too many pictures during this phase as I started shaping and got carried away and it was done before I knew it, but I started out using a makita angle grinder and dremel tool and then some sandpaper.

 I used lots of reference photos of skulls found on the internet to get it somewhat right but still took a little artistic license, I wasn't going for accuracy here, just a cool sign.

Step 5: Epoxy Coating

I coated the skull in epoxy putty called magic sculpt, it's similar to JB plumbers putty but has a working time of over 3 hours depending on temp. It's available in 4, 20, and 100 lb kits, it's a two part system mixed up in equal amounts and kneaded together for a few minutes. it's great for adding in detail and texture and as a rock hard coating.  

Using the urethane foam, this step was not absolutely necessary, but I did carve away a little too much in some areas. If your using the insulation foam you could also use bondo or snow seal roof coating to build up areas and add texture.

Step 6: The Signboard

The next step was making the board that the skull and lettering is mounted to. It was chiseled on the edges and face to look a little like the rock that a fossil would be embedded in. The final thickness was two inches. I made a support for the skull by welding two pieces of 1" square tubing into a T shape and gluing through the background into the skull.

I cut the lettering from some 1/2" material I had leftover but could have used plywood or mdf,
and the layer the lettering is on is 1/4" sintra pvc but could have been plywood or masonite, whatever you have.

Step 7: Prime and Paint

The next step was priming the piece in preparation for paint. I used Coastal Enterprise's  primer filler FSC-88 WB. it is a very thick primer useful for adding extra texture to your piece.

Step 8: Add Paint

the final step is painting, I didn't get any pictures of this step as I was having too much fun, but I picked some colors for base coats and then added some home made glazes to help bring out the texture that I had added in the previous steps.

I routed a 1/2 in. deep hole in the back and fastened a french cleat for hanging

See more of my work at:

and my blog at:

Step 9: Contact

you can see more of my work at the links below and if you have any questions, please do not hesitate, I will help out where ever I can.

contact Coastal Enterprises for samples and information

3rd Epilog Challenge

Participated in the
3rd Epilog Challenge