Building the M-3 Predator Heavy Pistol from Mass Effect 2 Part Two: Moldmaking

When last I wrote about this particular project it was all sorts of good-looking, like so:

As I mentioned at the time, it looked good but it was cobbled together from a variety of materials and it was a bit on the heavy side.  Plus, it suffered from an unfortunate case of being the only one I had.  Since I needed to send one to someone else and I wanted to keep one for myself (and I would probably make a few to sell to friends to offset costs) I had only two choices.  Either I would have to invent some sort of molecular replicator technology or I'd have to make a mold. 

I went with the mold making option.

The rubber I'm using in this case is AM128 Silicone RTV (Room Temperature Vulcanizing) moldmaking rubber from aeromarineproducts.com.  I buy from them because theirs is the lowest price I've found for silicone anywhere.  Even with the cost of shipping.  

AM128 moldmaking silicone also smells like grape-flavored bubble gum.  Don't eat it.

Silicone is a wonderful thing.  It has the ability to stick to nothing at all.  This is why you see so many cooking utensils made out of different grades of silicone.  In fact, the only thing that can stick to silicone is more silicone.  When you make a mold out of it, that means you can pour resin into the mold, wait for it to cure, and pull the cured part out without using any grease or mold release to prevent it from sticking to the mold.  It also has amazing detail reproduction properties.  There are actually certain grades of silicone that are used to duplicate cellular structures for later study in medical applications. 

There are a lot of different ways to go about making molds and each is great for certain things.  In this case, I opted for making a simple, two-piece box mold.  This means I'll have two chunks of rubber that fit into a box and there will be a hole in between them that's exactly the same shape as the original model.  When you pour resin into that hole and allow it to cure, it will form a copy of the model.  Here's how.

To make a box mold, you start by making a box:

This particular box if made out of Medium Density Fiberboard (aka "MDF") that's 3/4" thick.  There are better options for these applications, but none of them were laying around in oddly sized and shaped scraps all over my workshop.  So MDF it was.

When building the box, the key thing to do is make sure you've got 1/2" of clearance all the way around the original model:

As you can see, I'm making both parts of the pistol in one mold.  This way I don't end up wasting a bunch of time and silicone making a whole 'nother mold.  You also want to make sure that the box won't leak.  For that, I just pushed a bit of oil-based clay into the seams to act as a sort of caulking.  Finally, you'll be taking the box apart a couple of times during the process, so use screws to hold it together.

Once I'd decided I liked the layout, the next step was to lay down a bed of clay to hold the model in place.  Since you'll be making a two-part mold, the shape you're making the clay in now will become the shape of the second half of the mold.

The first priority at this point is making sure that the model is tightly sealed in place.  At this point you're also deciding where the two halves of the mold will separate.  I try to follow along the edges of the model so that the seams will be easy to clean off.

Here's what the clay wall looks like once it's mostly formed:

When designing a mold, you have to give ample consideration to how the resin will flow into the mold as well as how air bubbles will flow out of the mold.  In this case I plan to pour the resin into the back end of the pistol next to where it's labelled "model 85C" above the grip.  Because air bubbles are likely to get trapped at the high points at the back of the grip and the rear sight, I've added vents there.  I've also set up "sprues" which act as pour spouts and vents between the main portion of the pistol and the removable body panel.  Those are the white plastic tubes running between the two pieces.

Finally, you need to set up "registration points," which are little holes that will line up with the little bumps on the other half of the mold to ensure that the two halves are properly aligned.  In this case, I simply pressed the rounded end of one of my sculpting tools into the surface of the clay to make oodles of little dimples:

Satisfied that the clay wall was just right, the next step was to pour the first batch of silicone.  This is often called the "print coat" as it picks up all of the minute details on the surface of the original.  Here's the first pour of about 23 fluid ounces of silicone RTV moldmaking rubber:

A note about silicone: READ THE INSTRUCTIONS.  If the manufacturer says the material must be mixed to a certain ratio by weight, you're going to need a scale in order to do it right.  Do not try to eyeball it or you're going to end up wasting a lot of material in the best case.  Worst case you'll waste a lot of material and ruin your original model in the process.  There are some types of silicone that can by mixed by volume.  They tend to be weaker and softer and wear out faster.  If you've got a mold that has finally failed due to age or overuse, don't throw it away.  You can cut it up into chunks that can be re-used as filler.

Anyhow, after the second or third batch of silicone, it was becoming clear that this mold was going to use up a small fortune in rubber goo.  Fortunately, I've got a few other molds laying around in the shop that have long since given up the ghost.  So I hacked one of them into bits and sunk the bits into the still-liquid silicone to take up space.  They were a different brand of silicone, so you can see them as blue chunks:

Once I'd squeezed as many rubber chunks as I could into the silicone, I poured one more batch on top just to hide the fact that I had recycled rubber inside:

The main challenge at this point is to leave it the hell alone long enough to properly cure.  I actually had to take a whole day off from being in my workshop just to resist the urge to pull the mold apart before it had properly cured.

The next day, I flipped the mold over, unscrewed the bottom of the box, and started pulling the clay off of the underside:

With the box and the clay removed, the first half of the mold looked like so:

Notice that everywhere I put a dimple into the clay, there's now a bump in the rubber.

As I mentioned before, silicone doesn't like to stick to anything except more silicone.  Now we have to pour the other half of the mold, but we don't want to have the two halves stick together and ruin all of the cute little dimples and bumps.  In order to prevent them from touching you'll need some sort of mold release.  There are all sorts of commercial options available, but I've found that a very light coat of Vaseline works just fine.

Once you've coated the first half of the mold with silicone, the next step is to reassemble the sides of the box around the mold:

When you do this, you want to set the sides of the box a bit higher than they originally were.  This way, after you pour everything, the box won't be quite as tall as the rubber mold.  When you reassemble the box, you can clamp it together a bit and help seal the two halves of the mold together.

Once the box is sealed around the first half of the rubber mold, it's time to pour more grape-scented goop:

And more:

And even more:

You may have noticed all of the bubbles in the pictures above.  One benefit of building the box mold like this is that the bubbles rise away from the surface of the original model.  You can do a lot of other things to eliminate the formation of bubbles in the silicone (such as putting the mixed silicone in a vacuum chamber) but with this method you really don't have to worry about it too much.

After allowing proper cure time (in other words, resist the urge to screw with it), the next step is to disassemble the box and pull the two halves of the mold apart:

Now you need to pull the original out of the mold, clean off the Vaseline, and allow the rubber some time to dry out.  Even so, your first pull will likely end up with a bit of Vaseline residue or tiny bits of clay stuck to it.  I usually call the first cast a throw-away.

Once you've let the mold sit for a few hours, reassemble the box with the rubber mold inside.  At this point, you'll leave off the side of the box where your pour spout is.  Make sure to tighten the lid on the box just enough to squeeze the two halves of the rubber together so they won't leak.  If you make it too tight, you'll likely distort the shape of the hole you're about to fill.

Then set the box on end and pour resin into the pour spout until it fills up to where you can see it coming out of the vents.  As you pour, tap the mold or shake it gently to help any trapped air bubbles work their way out.  The resin I'm using is also from aeromarineproducts.com.  They have urethane casting resin in off-white (cheapest) black (a bit more expensive, but more reliable and faster to cure) and clear (most expensive, very temperamental and hard to work with).  In this case, I used their off-white resin with some black pigment added in to make the casting grey and microballoons added in to make it a bit lighter in weight.

Here's the first cast coming out of the mold:

When I mentioned that the silicone picks up details very well, I wasn't kidding.  The lettering and logos you see in these pictures were vinyl decals that were stuck onto the prototype.  They're no thicker than a sheet of paper and you can clearly see them and feel them on the castings.

For those of you keeping track, the mold took up something like 100 fluid ounces of silicone plus some leftover chunks of older molds.  The casting itself used up about 42 fluid ounces of mixed resin.

At this point, all that's left to do is cut off all of the "flashing" where a bit of resin has seeped into the seams of the mold as well as removing the extra plastic formed at the vents and pour spout.  That, and make another cast:

Or lots of casts:

Then all you need to do is find an appropriately attractive model to help show off your creations:

Stay tuned for Part 3: Wiring, Blinky Lights, and Painting.

.

Predator: the Musical

From the same group that brought us Terminator 2: the Opera and Conan: the Musical. Apparently this will be their last Schwarzenegger musical, so enjoy it for all it's worth.

Yard Sale Find of the Year: Stan Winston Predator Statue

Monday morning I got an interesting picture from my father via text message asking me if this thing was something I'd be interested in:



As soon as I saw it, I instantly recognized it for what it was.  It turns out that when they'd finished making the production costumes for the original Predator film, Stan Winston Studios (now known as "Legacy Effects" with the passing of the late great Stan Winston) made four of the foam-filled statues which since found their way into the hands of private collectors.  Then the molds ended up in the hands of Magee FX, who made a few more.  When the molds started to deteriorate, Magee FX resorted to selling partial statues with no backs on them so they'd have to lean against a wall.  The backless statues currently sell for $3799 and if this is one of the few with the full back it'd be worth even more.


I told him that if he could get it, but when he asked it turned out that the seller was claiming it had already been sold.  BLAST!


The next day Dad decided he had to go back for a second look at the rest of the stuff for sale and invited me to join.  When we arrived, we found the same wildly eclectic collection of furniture, tools, golf carts, and statues that were there the day before. 


The same piece was still mixed in with all of the other oddness:



It couldn't help but look out of place:



Closer inspection revealed that all of the key details were intact:



It made me fell pretty good about the paintjob I did on my costume a few years back:



Being taken from the original Stan Winston Studio molds, every aspect of this statue was a perfect reproduction of the screen-used costume.  Unfortunately, to save on reproduction costs, the face was left unfinished and the mandibles were removed:



As I was looking it over, the buyer and his wife turned up and I got to chat with them for a bit before helping them get it out of the pile of random statues and posing for a picture with this great piece:

It was originally designed to fit the late Kevin Peter Hall (who stood 7'2" tall) so it's not small.

This is the worst part: there was a base included with the statue that had a pin to insert into the foot so it would stay upright.  When we were trying to attach it, the Predator kept drooping forward at an unnatural angle.  While we were struggling with it, the seller mentioned "I've got another one of those, let me go grab it"


When he came back, he had another base of the same basic design but with the foot pins in different positions.  When asked where this one came from he said that when he got the Predator statue, there was another one with it that was some kind of big, gray animal skeleton, but it was all in pieces and he threw it away.  Given that Magee FX also sells a few other things with similar bases, I'm pretty sure he threw away one of these.


The head alone would've been worth almost $1400!

Damn.

Past Project: Predator Costume

Since Halloween's coming up, I've decided to do writeups about some of my old costume projects.  First up: the Predator.

For Halloween 2005 I decided to go as the creature from the Predator movies.  I built this costume in my woodshop over about two months worth of nights and weekends.  If you'd like to do the same, follow these simple steps.

To begin, build a body double. You'll need a set of easily cut, disposable clothes and about 5 rolls of duct tape. Have an assistant wrap you in duct tape until it feels like you can't move anymore. Ideally, you'll look something like this:

Then cut off the duct tape and the clothes it's attached to, get dressed, and tape the seams of your duct tape mannequin. Stuff the duct tape skin with newspaper or something similarly lightweight. Then dress it with the bodysuits that will become the foundation of your musclesuit. Now it's time to start sculpting the muscle masses out of upholstery foam:

When you've built your musculature enough for it to be convincing, it's time to coat it with liquid latex. It took me five coats to get a skin like this:

In hindsight, I should have made the arms separate from the torso. This would have allowed for a greater freedom of movement and the armor could've been designed to hide the seams. Oh well.

Once the latex skin has dried thorougly, it's time to paint. First I painted just the lightest and darkest parts (black and a mixture of flesh, white, and yellow colors) and then blended them in with some brown shading:

The next step is where you'll end up with carpal tunnel syndrome. To really bring this character to life I started adding the spots:

And then a clearcoat to make it look wet:

The same process was used to make the legs for the musclesuit.

The feet were made the same way only they were built on top of a pair of cheap high-heel boots that I destroyed for the purpose. These were mounted to a couple of pieces of 3/4" plywood which would become the soles of the creature's feet:

And built up they looked like this:

The claws were made from Sculpey brand polymer clay, and the armor plate was made using Sintra brand PVC sheet. The rest of the armor plates were made the same way.

Essentially, Sintra is cut to shape and bent using a heat gun to soften it. Once the desired shape is made, the edges are sculpted using an epoxy putty. When the putty has cured, the parts are primed, painted, and weathered. Then they look like this:

I also needed hands. These were a custom sculpt over a lifecast of a friend's hands. Once I had finished the sculpt I made a mold and cast them in latex. I would've preferred to have them start in the same pose, but my hand model took direction poorly:

The hands were painted in the same way as the musclesuit and feet.

At this point I was starting to run out of time, so I found another similarly deranged person online and bought a raw latex cast of a head sculpt he had made. When I received the head, it looked like this:

When I had finished adding dreadlocks (pre-caulking foam filler rod), quills, teeth and paint, it looked about like this:

At this point I had also been working on the gauntlets. I stripped the working parts out of an LED belt buckle for the computer readout on the left side. For the right side, I ground some aluminum stock into a pair of blades. You can't see it, but there's a notch in one of them so I can use it as a bottle opener. I also have them mounted on a track so that I can extend them with a flick of the wrist and retract them via a spring mechanism. The gauntlets open in clamshell fashion with a pin that keeps them closed when worn:

The only thing that was left at this point was the fishnets, the leather work and the loincloth. The leather was bought at a local saddle shop. They cut me about four feet worth of 1-inch strap for a very modest price. The loincloth was a piece of faux suede that a friend of mine hemmed to make it look a little more substantial. The fishnets proved to be a bit more difficult than I'd anticipated. It turns out that what I was looking for wasn't fishnet, but "industrial net" with bigger holes. The biggest holes are found in "fence net." Now you know as much as I do about women's hosiery.

For the Predator I managed to order an industrial net catsuit (one size fits all, with "convenience crotch") that only barely fit over the massive biceps and shoulders of the assembled costume. With the addition of a few little bones and teeth, the whole assembled costume looked about like this:

It added at least six inches to my height and managed to impress just about everyone that saw it. The only drawback was that with all of the foam and rubber built into it, it was about as cozy as a two inch thick wetsuit. Suffice it to say that I was a bit warm. The shoes were a bit uncomfortable, so I couldn't walk for very long distances. The only other part that was uncomfortable was the contacts:

If for some sick reason you'd like to do this to yourself, the following websites will be helpful:

The Hunter's Lair: http://www.thehunterslair.com

Monster Makers: http://www.monstermakers.com/

Enjoy.