Geek Out : Making Molds

Since the early 1990s, I’ve been experimenting with mold making. It started back in the days when we had these miniatures from Games Workshop. The supply lines were choppy and the prices were high. We used to stay up until 1AM to phone Games Workshop and order Titans, Gargants, etc.. We thought: hey, couldn’t we make this stuff? Yes, it would be a tremendous violation of copyrights, but I wanted to field two more Gargants, dammit!

Sculpey figure of a Cthulhu embyroI started with this stuff called Rubbertex-- liquid latex that could be built up over. Latexing the mold was a long ordeal-- the molds were stiff and prone to tearing-- not ideal at all. Then we tried this liquid resin stuff that made dense, sticky annoying results. I came across these original molds a few weeks ago and happily tossed them.

After the figure counterfeiting failed, I turned to mask making and costuming for a while. Variants of Borg outfits. I dressed as a giant shelled thing that people quickly dubbed “Shrimp Boy.” I sold off some of my Borg masks and one guy saw it at the mask shop (yes, Victoria had a mask shop under the helm of the late and sadly departed Tony Eng) and he dashed off to get his hair cut to accomodate the mask. I sold off all of my Borg stuff before a move. A friend at a bank said that my outfit had been fit into a display of “The Future”-- it’s good to know that bank has in store us....

My workshop - a shed built in the backyardWithin a couple of moves, my mask making and tinkering space had diminished to the point where it was a stack of rubbermaid bins on the deck subject to the elements and never available for me. We moved to our current house and for the last three years, my stuff has been accessible but buried. A few months ago, I was able to get my workshop ready: a 100 sq. ft. shed where projects can sit in place and not collect cat hair or rain.

The idea that a project can sit is huge for me-- likely for any moldmaker. Whatever you work in-- silicon, latex, water putty-- it needs to set for a little as an hour or as much as two days. So the workshop is a huge win. Over the years I have collected supplies for mask making with the idea I would eventually get to use them.

For a long time, I’ve been building Cthulhu creatures-- I made a man-sized Cthulhu, I made a set of bat wings / Cthulhu wings (4 ft. across each). And I’ve made lots of creatures in specimen jars. With each one, I’ve done them in sculpey. The upside is that they’re sturdy. The downside is that they take a fair amount of effort with each creation. So, I’ve tried to make a mold to cast these creatures. Then, I can turn my attention to making each one distinct.

Exhibit A: The JarI started with a concept. I want these to fit in some great specimen jars I had. I wanted to do Cthulhu embyros. I wanted to have a very sturdy mold and I’m cheap. So, the rules:

  • I want flexible molds to make firm or rigid creations
  • using liquid vinamold as its re-useable.
  • a model that would not melt under the high heat of liquid vinamold
  • I wanted them to fit into those jars.
  • I wanted the creatures in the jars to be inexpensive, well-defined and durable.

I common mold flexible to firm. If the cast (mask or creation) is made to the flexible, it can go in a rigid or firm mold. The model that I make the mold from would need to be flexible. All that said, you can start with a rigid model, a firm mold and use it to create flexible casts. That’s how I did this Cthulhu embyro.

I made the model from sculpey or polymer clay. It’s easy to work with and can be baked to become solid. Polymer clay takes so long to bake based on thickness, so the thinner it is, the faster it bakes. And the thinner it is, the less material it takes to make a creation. A cheap, bulky foundation that I use it tin foil. It can be shaped and worked up, it holds its shape and its hard to burn (as a kid, I’ve done it, but that’s another story).

IMG_7704I formed up a shape that can fit into the jar. Then I rolled out a consistent thickness of sculpey. I applied the sculpey to the tin foil to get a layer of coverage. Then I re-assessed if the figure would fit. It couldn’t so I squeezed the shape a little. I went to work on the details: arms, legs, tentacles, etc.. I folded all of the bits into a compact embryonic shape until it fit into the jar.

IMG_7740I poked some wires into the shape to act as feet to keep the sculpey suspended mid-air during baking. Sculpey softens a bit before it bakes, so if you put a figure onto a flat surface it will pick-up that flatness.

I baked it for the right amount of time (look at your sculpey box for directions), then I let it cool.

On to vinamold. Years ago I heard about this cool stuff called “Vinamold”-- there were two places you could buy it. Surrey, UK and Nanaimo, BC. Cool for me-- Nanaimo is two towns over. I bought some small amounts for experiments. Then I found that the supplier in Nanaimo couldn’t unload the stuff. The price started to drop: at a hobby store I saw a small piece sell for $20 for an 8oz. brick. I was buying 10lb. buckets for $20.

Vinamold is re-usable (reduce, re-use, etc.) so it wins vs. silicon. Set vinamold won’t bond to liquid vinamold, so it beats latex on that front. The downside is that it has a thin window where it’s liquid and not smoking. The window is so thin that one part of the vat of vinamold can be solid while the other part is smoking. Beyond that, it pours at like 300° so whatever it touches it can melt (eg. no plasticine, please).

I tried everything to melt vinamold. People has suggested microwaving it, but I’ve never had any luck with that. So, I stayed in the kitchen and looked around. I tried an electric frying pan: nice control of temperature, but it’s open shape vented too much heat. I moved onto a deep fat fryer. The ideal tool for the job is an industrial melter. I don’t have that kind of money or space. Stirred vinamold I’ve used a deep fat fryer to some success. Because of the islands of cooled vinamold, I have an extra tool: a heat gun. Heat guns are used to belt out a crazy amount of heat, so they have to be used carefully. When the fryer melts the bottom, I can use the heat gun to get it from the top. All the while, stirring is an excellent way to make the vinamold melt as evenly as possible.

Plasticine embedded moldWhen I get the melting casting process underway, I start the melting as soon as practical as it takes a long time. Then I get onto the prep of the model.

I found a vessel that the right size to hold the model. To make a two part mold, you have to fake out the underside, cast the top, remove that underside, flip and cast. Air bubbles rise, so you always want them to rise off of the model and escape. I built the bottom with tin foil, then evened it out with a layer of plasticine. I know-- plasticine melts, but I’m using it to make a consistent layer, so getting it into the nooks and crannies at the last instant is okay.

The Vinanold in its formWhen the vinamold is ready and the model in its vessel is ready, I can pour the vinamold. I pour out as much as I need-- usually filling the mold. Then, the long cool down period begins. Vinamold is solid and will not stick to itself even at a high temperature, but even so, it can be too flexible to be practical. Colder is better.

IMG_7791After the first half has cooled down, removed it from the mold. Then, I popped out the figure to be able to clean it and remove anything undesired: plasticine, tin foil and bits of vinamold that could inconvenient. Then, I popped back in the model, snugging it into its place. I made a corral of tin foil. I set to melting more vinamold. When liquid, I poured it over top of the model and the already set vinamold. Back to the setting and cooling.

IMG_7799Eventually it sets and cools (figure it an hour and you can speed it up by popping it into the fridge). I carefully separated the mold halves and then popped out the model. Hooray! I have a mold.

I have many more photos available in my Flickr account.

Part II is coming soon: Making the figure from the mold.

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