Prop Making 101, with Sarah Kaiser – Part 2

In Part 2 of Sarah Kaiser’s guide to building a bolt rifle and plasma incinerator for the Community team, she explores building realistic looking plasma coils, painting props and the fun bit – showing them off at Warhammer Fest! You can catch up on Part 1 here.

Part 5: Fabricating

The hard part done, I jumped into the most familiar part of the process for me: actually making the thing look like the thing. With only two weeks remaining, how I’d make the plasma coils was still the most mysterious part, so I tackled them first to allow time to fail and try new approaches.

No matter what method I ended up using to create the transparent shell, I knew I’d need to prepare a sculpt of the coils in a sturdy material to mould or cast from. I chose MDF because it’s cheap and easy to cut and sand, but is more durable than foam.

So I went to work with some scrap I had lying around and cut and routed them into the ‘coil’ shape I’d need with the help of template and bandsaw. Time allowing, I would have used a CNC instead.

I experimented with edge radius and found a smooth bevel to be the preference to merely a rounded edge.

A couple hours later and:

That part was easy enough, but the creating a shell from my ‘mdf loaf’ as it came to be affectionately known would be much harder. Normally, one would seek out a vacuforming table (which heats up a plastic sheet and then sucks it down around a part to make a hard, clear shell) but for all the things my workshop does have, this is not amongst its repertoire.

So the first attempt was spirited. Three friends, four heat guns and some PETG (a clear, heat-reactive plastic) gave us a hot mess that was close enough for me to test out some diffusing sprays I wanted to use but wouldn’t be close to a final product.

Fortunately, I had a friend with access to a very nice vacuformer. And said friend likes beer. Beer is a common currency/bribe around these parts.

Foiled again, this time by the height of the part. No matter what we did, the plastic would pull loose as soon as it was pulled down over the buck. It’s not you, Formech, it’s me.

Now, with a week to go and fewer options left to me, I was looking at two different avenues. Custom rubber mold and slush cast a brittle resin part (an expensive, messy, and time-consuming process for a part I would only need one of) or try out something I’d never worked with before: transparent worbla. Fortunately, I’d ordered some just in case.

Time to try some new things.

A test produced some promising results.

So it was time to take some risks with an expensive sheet of Transpart, as it’s called. Doesn’t exactly roll off the tongue.

But it sure as heck works. Not as transparent as one might like, but perfect for my purposes. To their credit, most of the murkiness is due to the MDF not being properly cleaned off and my own inexperience with the material.

And with the tough stuff out of the way, it was time to start properly putting it together.

I like to use EVA foam for exteriors. Durable, cheap, available in a variety of thicknesses, easy to cut, shape and glue, and used in everything from Space Marine cosplay armour to interior padding, EVA is a cosplayer’s best friend. Here, my small modicum of sewing experience comes in handy when creating custom ‘patterns’ for pieces that will easily wrap around the pink foam interior.

Each piece is quickly and carefully measured, proportioned, and occasionally made victim of some quick division to provide even spacing.

A steady hand, a ruler, and a fistful of fresh craft knives can create some really nice mechanical shapes with some time and patience.

Eventually it came time for the handles to start looking like their design spec. As I was coming up on the final days and needed something quick drying, strong, and easy to sand, this would require some special sauce. There’s a saying that goes: the more warning labels something has, the more effective it generally is. This saying is not wrong.


The handles were both caked in body filler sometime after 1:00 am on a Sunday, three days before I had to pack up to leave. By the end of the ‘night’ I had two sanded, custom shaped handles, two primed and drying props, some scuffed up hands, and a Monday in the office that would require extra coffee.

Part 6: Priming and Painting

With three evenings to go before they would need to be transported to a convention full of painting enthusiasts, I knew exhaustion and limited time would not be a valid excuse for flubbing a paint job, so there was no choice but to get smart about how they were painted and do it right the first time. EVA requires careful priming to paint well, and spray plastidip is the ticket to getting a smooth finish that hides its giveaway porous texture. But to do that, every square of pink foam would need to be covered by foam or acrylic or else the aerosol would melt it. Many have experienced this property of insulation foam first hand, myself included.

Both guns received two to three layers of plastidip, and could have done with a couple more. The places where they got the most attention look deceptively smooth and metal like on the surface. The places that received little priming look foamy and porous in comparison, but fortunately, they’re tucked away in harder to see spots.

Color took some experimenting. Macragge Blue works great on plastic miniatures… less so on rubber casing.


Some automotive paint later, and we’re getting closer to a final result.

As for metal, some research and asking around delivered me at a solution with my narrow-pattern airbrush. Rub-n-buff is a furniture restoration wax that can essentially be dry-brushed on with a rag to create a very convincing metal surface, assuming you start from black.

Some detailing later, and you have yourself a nearly finished gun, complete with a suitably gothic base.

Part 7: Programming

The constituent parts of the props were all tested and operational, and with the physical demands mostly out of the way, it was time to start programming some behaviour into the plasma incinerator. This was something that could have taken a week, and even now there’s so much more that could be done with it. In a day, with Andrew leading the charge, we managed to add in machine states that included idle, recharging, discharging, and even a ‘party mode,’ which few have witnessed or know how to access.

Had I lacked his help, I no doubt would still be ironing out the bugs and would have had to stop at idle, discharge and battery sensing, for having all of a day to work on it.

Part 8: Packing and Delivery

The ‘hard’ part was done. Now all that was left was to fly with two props which, together with their boxes and accoutrements, weighed more than me! All to a city I’d never been to, in a country I was only loosely familiar with. Easy!

Made easier, again, by a hand from friends. Props again to Science Bob for coming through with perhaps the most clutch and befuddling case the TSA has ever had to probe, and Jason for throwing together a second in an hour.

Love notes to the TSA were drafted and affixed at every possible angle, explaining their contents and begging mercy in defence of a box packed with a month’s worth of sleepless nights, trial and error, and every ounce of effort I’d had to give. It was going to be a butt-clenching plane ride to be sure.

And mercy was granted as both boxes arrived in perfect condition, without even a dent or a scratch. The TSA had even left me love notes in return, of the official inspection variety.

Save some convention security related hiccups, soon the destination was in sight.

All in all, it was a whirlwind of a month, full of new and familiar challenges, a lot of hard work, and more than a few helping hands. For the curious, my own time investment in this project was just north of 160 hours in the off-hours of one month. I’d estimate another 20 hours of my friends’ time could be tacked onto that. Material cost was somewhere south of $250 in electronics, and about $200 more in raw materials. (Mostly in terms of paint, piping and EVA – the pink foam is negligible.) This was in addition to working 45 hours a week on average at my day job as a product designer at a software consultancy.

The Community Team made it well worth it at the end of the day, and I had a hell of an adventure. Months later, I’ve finally recovered, dusted off my social life and caught up on some sleep, but I certainly checked off some bucket list items at Warhammer Fest this year.

I hope you all enjoyed my props, and with any luck, you’re feeling slightly more informed and ready to tackle your own projects. I hope to see you and any of your creations at another event someday, perhaps at AdeptiCon where I’ll have something new to show off!

Cadia Stands!
– Kaiser

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