Making Hard-Shell Molds with Adam Savage

Making Hard-Shell Molds with Adam Savage

Most folks know Adam Savage as co-host of the show MythBusters, but this multi-talented maker has additionally worked as an animator, graphic designer, carpenter, projectionist, film developer, set designer, toy designer, and gallery owner. One of his passions is modelmaking, and he’s built models for Star Wars Episodes I and II, Space Cowboys, A.I., Terminator 3, Galaxy Quest, Home Alone III, Bicentennial Man, Matrix: Reloaded, and Matrix: Revolution, to name a few.

It’s one thing to know how to make something and an entirely different talent to be able to provide clear instructions so others can share what you know. Adam is talented on both fronts, and his Hard-Shell Mold primer that originally appeared in MAKE Volume 24 is an evergreen gem well worth revisiting.

From his intro:

Silicone block molds are fine for making casts of small objects. But for larger items, like this 3′ prop gun, you’d need hundreds of dollars’ worth of silicone to make a block mold.

An excellent and inexpensive solution is to use a thin layer (or “blanket”) of silicone, that’s keyed to a hard-shell or “mother” mold. It’s a multi-step process, but it yields great results for the cost-conscious mold maker. It also makes much lighter molds, which are easier to move around.

With this type of mold making, you’re basically sculpting the 2 sides of your mold, taking into account the forces involved in the pouring and casting of the part. It takes a while, but if you get good at hard-shell mold making, you can cast just about anything, no matter how big.

Check out the full step-by-step starting on page 108 of Volume 24, or online at Make: Projects. There’s still plenty of time for you to create the awesome prop that will totally make your Halloween costume!

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I'm a word nerd who loves to geek out on how emerging technology affects the lexicon. I was an editor on the first 40 volumes of MAKE, and I love shining light on the incredible makers in our community. In particular, covering art is my passion — after all, art is the first thing most of us ever made. When not fawning over perfect word choices, I can be found on the nearest mountain, looking for untouched powder fields and ideal alpine lakes.

Contact me at or via @snowgoli.

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