A couple of months ago, the video card on my 5 year old PC finally gave up the ghost. I reached out on twitter to see if anyone had a spare around that could keep me going for a while longer. The folks at Doghouse Systems contacted me and we ended up formulating a plan that involved them sending me a whole new computer in exchange for me building them Kerrigan’s Ghost rifle to use as a promotional giveaway. What a fantastic plan! I was so excited for the project and I jumped right on it!
I knew that I would need to make more than one copy of this gun, so I planned on building it in a series of parts that would be molded. Since I was on a tight deadline, photo coverage was a bit spotty, so I’ll do my best to paint you some pretty word pictures.
Of course I drew up some really detailed blueprints. Like always, I printed it out full scale to use as templates. In fact, the blueprints are for sale on my store here!
I started with one of the most complicated pieces; the scope. I cut out the side and top profile shapes out of 1/4″ MDF and glued them together. The empty space between them was filled in with rigid insulation foam. This cheap, lightweight material is great for taking up space inside the body of a prop piece.
Then I covered most of it in Apoxie Sculpt. This stuff is amazing. I sculpted it down to a close approximation of the scope shape and was able to sand and refine it after it cured.
I lathed the front element of the scope from a chunk of extra polyurethane plastic. The hood cover was cut from thin styrene and glued into place. Everything was sanded and smoothed down into the final shape.
The barrel was actually one of the more straight forward parts on this project. Of course I did most of it on my lathe, but it was way longer than my lathe, so I did it in two pieces. The lathe blanks were cast from polyurethane resin in cups and tubes that were roughly the right size and shape as the final parts. I also sunk PVC tubes into them to save on space. Check out my quick tip video below for using extra plastic resin!
Both barrel pieces got turned on the lathe and everything got primed/sanded a bunch. The plastic resin ended up with a bunch of tiny bubbles that were a pain to fill in, so it took a couple of tries.
The two barrel pieces were attached into one large piece. The vent holes required a bit of engineering to get right. I ended up modifying a cheap spade bit to perfectly drill the holes and the recessed bits around the outside of them with my drill press.
The more oblong vent hole things were a different story. I ended up making templates out of some thin aluminum sheet, taping them down to the surface of the barrel, and cutting them with a router bit on my Dremel.
The receiver of the gun was where I spent most of my build time. This part, by itself, is bigger than any other gun project that I’ve built. It started it’s life as a couple of sheets of 3/4″ particle board. In hind sight it would have been way better to use MDF, but I didn’t have any on hand at the time and I needed to get started toot-sweet. The two cut out shapes were glued together.
The magazine was made in the same fashion. I started adding slices of detail that were cut out of PCV foam and styrene. It was at this point that I realized that I could get MDF in an 1/8″ thickness and should have been using that instead of the vastly more expensive 1/8″ PVC.
The magazine got some more refinement and beveling. I also added a hex shaped screw. Everything in the future is hexagon shaped, by the way. I also cut out some thicker, sloped pieces out of MDF for the front end of the receiver. If you squint, you can also see where I cut out a hole and added a tube to receive the barrel where it attaches to the main body of the gun.
The front end of the receiver was quite a challenge. I ended up using a combination of Bondo and Apoxie Sculpt to get the shapes just right. The side stripes were cut from styrene.
The weird rib things across the grip were also shaped from Apoxie Sculpt, right over the parts that I had shaped earlier.
I also got a head start on the butt stock. The main form was cut from 3/4″ MDF (yes I went and bought some, screw particle board). The tiny piston thingie was lathed from a dowel and I carved in some detail slots with my Dremel.
All of the detail pieces for the butt stock were cut from 1/4″ MDF, 1/8″ MDF and 1/16″ styrene. This is the “slicing” technique that I use for just about all of my gun builds.
To create a matching surface where the stock and receiver meet, I employed a technique known as the “Bondo Squish”. I put tape on one side and smeared Bondo on the other and then squished them together, holding them in place. When the Bondo was mostly set, I pulled the pieces apart and let the Bondo cure. The extra Bondo was trimmed away and sanded smooth. This way these two separate pieces would have a tight fit when attached for the final build.
The stock was finished, primed and sanded. The large, flat head screws were shaped out of a piece of dowel and cast using a clay push mold. The things that look like Philip’s head screws are actually Philip’s head screws. Here you can see that it resembles some kind of space chicken. It is my new shop mascot.
The receiver also got lots of sanding and priming. I also finished up the detail parts like the trigger, trigger guard, and barrel hood. Most of that was done with layers of MDF and styrene in different thicknesses, just like everything else.
I could have just painted the gun up at this point and called it a day, but I knew that I needed more than one copy of this gun, so I set about making some molds. This was by far the most time consuming, tedious, expensive, and emotional part of the build process.
I started with the barrel. For this one I tried something new. To save on silicone costs and time, I made it a one part mold. I used a wide PVC pipe as my mold jacket, centered the barrel in it, and poured in the liquid silicone from the top. Also, in the master of the barrel, I included a nub inside the barrel that would later be used to hold a threaded rod in the casting.
The PVC tube had been split on both sides, prior to pouring the silicone, with hinges on one side so that the mold jacket was kind of a clam shell. When the silicone cured, I cracked it open and cut a wavy seam in the side of the mold that was 90 degrees off from the slit in the mold jacket. I was able to retrieve the barrel master at this point and start casting barrels!
Again, I added a threaded steel rod into the casting before pouring my resin. This would ensure that the barrel was nice and strong as well as having a great way to attach it to the main gun body. I also added some insulation foam (not pictured) to the rod to take up some space inside the casting.
The scope mold was not so rousing of a success. My first attempt ended in a catastrophic clay blowout, resulting in a failed mold and a lot of wasted silicone. There were a number of factors that led to this failure. First, the walls of the mold box were way too thin. I used 1/8″ MDF and I needed at least 1/4″. Second, I didn’t put in enough clay to keep it stuck to the sloped underside of the scope master. Last, I poured in three batches of uncured silicone into the box all at once, filling the box. This added a lot of liquid weight to the clay. For the second attempt I let the first batch of silicone cure a little bit before adding the remaining goo.
The rest of the molds were pretty straight forward. They were all two part box molds. I did a LOT of claying. The receiver piece was especially time consuming. It was easily the largest mold I’ve ever made.
It took me 4 straight days of work to make the molds. It was a very trying time for me, but I made it through to the other side relatively unscathed! Casting the parts was actually pretty straight forward and extremely satisfying.
I painted the entire gun with Model Master’s buffable metalizer laquer airbrush paint. I went with a two-toned approach to add some contrast. The colors are Stainless Steel (lighter) and Gunmetal (darker). The basic process was basically: airbrush, dry, buff, seal, mask, airbrush, dry, buff, and seal.
For the tube thing on the stock, I bent a piece of 1/4″ aluminum rod and placed it into the eye holes of the space chicken.
Finally I did a lot of weathering on the gun. I wanted it to look like it’s been fighting Zerg for the last decade. I used acrylic black and yellow ochre paints to get a dirty, dusty look.
Then I added a couple of coats of matte clear spray paint and this bad boy was done! *gasp* This is, to date, my most challenging project; both technically and emotionally. Thank you for coming on this journey with me!