Over the course of this month, Punished Props' Bill Doran is building a 1:1 scale replica of the alien assault rifle from District 9 to unveil with us at Comic-Con. Bill's build logs and videos will walk through his design and fabrication process, and his finished piece will be paired with a surprise at SDCC. Place your questions for Bill in the comments below!
Welcome to the second installment of the District 9 rifle prop build! The project is moving along at a good pace and I've made a lot of progress. While the main body of the gun was made mostly in flat layers, there are a bunch of cylindrical pieces and it would be a pain to build them from flat sheets of material. Instead, I opted to bust out my lathe.
Working with Foam
For these pieces, I used a urethane tooling foam called RenShape. It comes in several densities. I ended up using the most dense foam I had. This stuff is so dense that you would think it's made of rock.
I was also made aware by my pal Harrison Krix that sometimes this kind of foam could cause curing inhibition in platinum cure silicones, so I performed a simple test. I took a small sample of each of the four densities I had on hand and dumped silicone over them all. Sure enough, the two least dense foams caused some inhibition, while the two most dense ones did not. Hence the decision to use the most dense stuff!