This is a prop replica of the amber cane John Hammond used in the movie Jurassic Park! My portion was the completion of the amber topper! This collaboration between myself and Pocket83 took us 2 years to pull off due to various setbacks and issues! It's great to finally be able to show this to you, as not talking about it for this long has been hard for me!
Step 1: Making the Mold!
I presumed that this process was going to take a bit of trial and error, so I decided to make a reusable silicone mold. I first needed a shape to be molded. This MDF block is 2 1/2" x 2 1/2" x 4 1/2"
One of the many flaws I'd seen in these topper replicas was the placement of the bug. By having a rectangular mold It would be much easier for me to get them in the correct location, or to make adjustments if the bug moved during the curing process.
I used poster board to build up a box that was slightly larger than my MDF shape. That box was assembled with some superglue and packing tape. The MDF block was then glued to the bottom with a couple drops of super glue.
Next is mixing up the silicone. I bought a 1lb package of silicone that just BARELY covered my object. You simply add the two halves in equal amounts and then stir till you get a consistent color.
There is something very satisfying about pouring silicone.
Once poured I had to wait 24 hours before it was ready for use.
Removing the MDF block was not as smooth as I had hoped. I would suggest wrapping the MDF in packing tape first before pouring the silicone. Or not, your choice.
Step 2: The First Pour
To measure the mold volume, simply fill it with water then pour that into a measuring cup. 11oz is what my mold holds.
My plan was to do a two part pour. I was going to use Polyester resin for a couple of reasons. 1. It's inexpensive and I was pretty sure I was going to need to make a couple casts 2. I could pour the second layer within an hour of pouring the first which streamlines the process. 3. Once cured it's much harder than epoxy resin and would shine up well.
The last point was probably the most important.
I started with 5oz of resin, 25 drops of catalyst and 7 drops of amber dye. Mixed thoroughly for 3 minutes.
The main reason for failed cast is poorly mixed resin. Don't rush this step.
I then poured it slowly into the mold trying my best to not create bubbles. With epoxy resin, you can use a flame to pop the bubble. DON'T try then with polyester resin. It's flammable, and you'll just light it on fire...
...Don't ask me how I know that.
Step 3: Bugs &The Second Pour!
This is a Crane Fly. They have a 10-day livespan and are considered pests due to the fact that they attack crops. Still, I don't want anything to suffer. The bugs were put in jars with a cotton ball soaked in lacquer thinner. They died in seconds. I wasn't cruel or vindictive.
After about 20 - 30 minutes polyester resin reaches this odd jelly stage. It's not cured but it can support the weight of another layer poured on top. It is also the best time to pour as it will help to minimize the look of line/layers that you would see in the final casting.
You've got one shot to place your bug. If it lands in the wrong spot (like this one) OH WELL. It's stuck and moving it will just result in it losing bit and pieces.
Another batch of resin was mixed up with the same formula and poured over the top.
I would like to tell you that my first attempt was a success. It was not. Nor was my 5th. In fact, it took quite a while to get this process right. Both with the color of the resin and the bugs. My final formula was 24 drops of dye, 12 in each pour.
What happens when you add a bug to resin that still has some moisture in it? It explodes and ruins the casting. Good news is, I really like the color at this point.
I ended up with close to 10 castings before I got two bugs well place and with the right color resin. Now we can move forward!
Step 4: Turning the Amber/Resin
I chose to turn this on the wood lathe so I could be in charge of the end shape and...
If you happen to follow me on Instructables you'll already know that I really like turning!
Polyester resin is VERY brittle and so I used super sharp carbide tools to work the blanks.
You can see how the resin chips even with sharp tools.Here I'm turning with carbide cutting tools. They work very well for this process, and even they will have some chip out. It's just a normal part of working with polyester resin.
It was just a long process but eventually, I got them down to shape that best mimicked the movie prop and showed off the bugs. As best we can tell this topper is larger by about 25% or so than the movie prop and Hammonds was more spherical than elliptical.
So while it's not a perfect replica I think it shows off it's best bits well!
Step 5: Sanding and Polishing
I think I have this step in 90% of my Instructables posts! Sanding and polishing can make or break a project.
The sanding started at 120 grit and progressed through 120, 150, 180, 220, 280, 320, 400, 600 and 800. It was all wet sanded to keep the plastic cool and help eliminate dust.
There's a shot of what it looks like after 800. Then on to polishing.
My micro mesh polishing pads start at 1500 grit and end at 12000. Again wet sanded.
That last shot is after the last polishing pad! SUCESS!
Step 6: Competed
Here they are completed. I ended sending them off to another YouTuber Pocket83 and he completed the cane build.
Here is the finished cane that was made by Pocket83. Pocket's Video:
Together we made a museum quality piece and I'm super proud of it! Thanks for looking!