BYNARS (Star Trek TNG) Making Prosthetics: 1. Life Casting (the complete bum’s way)

For years I’ve put off updating the makeup for my very first cosplay (from over 7 years ago now!) for one simple reason… I didn’t know how to go about getting a life cast made of myself, let alone how to make one for my partner in crime who lives clear across the country. I came across a tutorial by Emmabellish (who does an incredible Asari cosplay that you should check out immediately) that outlined a seemingly simple process for making a life cast that is *good enough* for some basic sculpting. Full disclosure: they look HORRENDOUS. They’re really just the worst. But, as promised, they were good enough to help make some pretty killer Bynar head prosthetics. I’m hoping my process might inspire some of you to give it a try.

I was able to make a decent life cast of Alison’s head while she visited for only a couple of days over Thanksgiving— after all, my Thanksgiving tradition wouldn’t be complete without a good ol’ Alison torture session in the name of cosplay. Again, it’s not perfect, but it worked, and more importantly, IT WAS CHEAP AND FAST. Here’s what you need to make what I will henceforth refer to as a “hobo” lifecast:

  • Plaster strips, cut into various sizes
  • A bowl of water
  • Cling wrap
  • Vaseline
  • ~30 lbs Ultracal 30 (This is a tough one… you can order it online, and the material itself is pretty cheap, but shipping will kill you. I found Ultracal at Reynolds Advanced Materials, which is a chain! Some local hardware or pottery stores around you might also carry it. Do some research before buying online.)
  • Home Depot 5-gallon paint bucket
  • Sand
  • OPTIONAL: Apoxy Sculpt or Free Form Air
  • Clear coat spray paint
  • Face mask (wear while mixing Ultracal to protect your lungs from fine gypsum dust)
  • Latex/vinyl gloves

STEP ONE: Preparing the model

I began by covering her head with the Press & Seal cling wrap, which easily sticks on both itself and the subject’s hair. I then covered everything, especially seams and any exposed hair, with vaseline. This is a super important step, unless you’re looking to skip your next facial hair waxing…

STEP 2: Creating the back half of mold

Plaster is pretty self explanatory… dip strips in water, ring them out a bit, place them on your subject, mold for a close fit. With this particular project, however, keep in mind that you have to make two halves that lock together neatly (otherwise your model cannot escape her plaster prison without destroying the mold).

For Ali’s, because I could actually see what I was doing, I started working from what I judged to be the center point of her head, and worked backwards. I left a small lip and built up layers starting about half and inch back from the edge of the first layer. (So in other words, do and entire layer or two on the whole back of the head, then on your next 2-4 layers, start about half and inch back, leaving a lip along the midpoint of the head that is not as built up as the rest of the mold.)


When I repeated this process on myself, however, I couldn’t see very well (and I had a not-super-artistic friend helping me). I found it was easier to make little bumps on the first half that I just molded the second half over. These were like “registration keys” that allowed my halves to “snap” in place. I didn’t take any pictures of this, unfortunately, but I just cut a small piece of plaster, dipped it in water, mushed it into a small ball, and placed it on the very edge of my back half cast.


Seriously, let it dry. Put on some Star Trek, drink a beer… LET IT DRY. We hung out for about an hour before starting the front half.

STEP 4: Building the front half of the mold

Once the back half is dry, throw another layer of cling wrap and vaseline over the seam where the back half meets your model’s head (and vaseline over your model’s eyebrows if you haven’t already), and repeat the process. Leave the eyes for last, and leave the nose holes open completely. Make sure the edge of your front mold piece butts up against the ridge in your back mold (with the thinner lip underneath the top layer). OR, build your plaster up over the registration keys you made. Both of these methods worked for me.


STEP 5: More waiting… let it dry… again…

This is a great time to get some killer blackmail photos. Be warned, untrustworthy friends in your presence while YOU are covered with plaster can also take advantage… Thanks, Phil.



STEP 6: Remove the dry plaster mold and prepare for casting

  • Fill in the nose holes with plaster. I like to ball up some plaster strips and shove them in the holes a little bit, just so that the edge of the nose is clear on my cast (the balled up plaster will amount to negative space on your final cast).
  • Allow your two halves to completely dry before messing with them. I let mine sit outside in the sun for a day. You can also fix cracks and major flaws with something like ApoxySculpt or FreeForm Air, but it’s not essential. After all, this is a ROUGH product in the end… it may not be worth the extra time to fix flaws.
  • Glue your halves together, carefully making sure they are locking in place in the exact same way they did on your model’s head. I actually completely failed the first time I tried making my own cast… I didn’t accept help, and my two halves didn’t lock together cleanly. When I glued them together they looked fine, but the cast came out clearly crooked.
  • Fix center seam on inside of the mold by applying a couple strips of plastic along the center line where the two halves meet on the INSIDE of your mold. Then apply a few layers of plaster on the outside for structural support.
  • Spray the inside of your mold with a couple coats of clear coat to help protect the plaster from the Ultracal that you are about to pour in.

STEP 7: Casting with Ultracal

Another disclaimer: I AM NOT AN TRAINED EXPERT. This method could be totally bogus, but I’m here to tell you that it worked… TWICE. Here’s what I did:

I filled a 5-gallon bucket about 1/4 full with sand, then balanced my plaster mold on top, pressing it into the sand enough that it would stay in place on it’s own.

I covered the opening to my mold with a damp paper towel, then filled the sides of the bucket (on the outside of the plaster mold) with sand to hold everything in place. Plaster is pretty week… supporting the sides of your mold with sand helps reduce the likelihood of the ultracal busting through and leaking everywhere. It also absorbs some of the moisture that is excreted as the Ultracal cures.


I mixed up some Ultracal. I wish I knew what to tell you about measuring; I ended up waisting a LOT of Ultracal because I just mixed what I thought might be enough. Ultimately, I would guess about 1/3 of a 50lb bag will do for your cast.

I bought some cheap plastic containers from IKEA, knowing I would just dump them at the end of this process. I estimated how full I wanted the container to be, then filled it with water to the half way point of that estimation. Then, I used the “dry river bed” method of measuring Ultracal, meaning I sifted in the Ultracal until it reached the surface of the water enough to crack a bit like a dry river bed (middle photo below).

Then mix. I personally like to just put gloves on and mix by hand (hence the long flat IKEA container… the ultracal wasn’t too deep for a gloved hand to mix), but you can also use an electric mixer or drill with mixing attachment. It is critical to break up as many clumps as possible!


Last but not least, I poured the Ultracal into my plaster mold, allowed it to cure for an hour or two, and ripped the wet plaster off to reveal my HIDEOUS, but effective life cast!




So here’s the problem. I have many wonderful friends with incredible talents… none of whom I trusted to entomb my face with plaster and algaenate. I was, however, able to find a willing assistant to at least cover the back of my head, knowing full well that the most important parts to get perfect were around the neck where a prosthetic would attach and the face, both of which I could easily do in a mirror. This process is hardly professional, and it certainly isn’t perfect, BUT IT CAN BE DONE ALONE.

Stay tuned for upcoming posts about sculpting, casting, and painting prosthetics!

2 thoughts on “BYNARS (Star Trek TNG) Making Prosthetics: 1. Life Casting (the complete bum’s way)

  1. Michael D Rough says:

    Well done! Ultimately if it isn’t toxic or harmful and it works then who cares about conventional. I have done lifecasting with alginate, silk, and long ago plaster bandages. The key to working with any of these materials is thinking your project through, having a plan, and patience.

    Liked by 1 person

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