Charcoal foundries can reach temperatures in excess of 1,000ºC, which is well above the melting point of hobbyists. This project should only be attempted with adequate knowledge and training, proper protective safety gear, and in a fire resistant area with adequate ventilation. The sparks flying from the foundry can ignite fires, and the fumes from burning dross can be toxic. Use caution and common sense. Be safe and have fun, but always remember that any project or experiment is at your own risk.
This project was inspired by 2 videos. If you check them out, please let them know that Grant Thompson sent you. Thanks! :) First was a “lost foam casting” tutorial by “The Art of Weapons” (http://bit.ly/IBRamboneSlingshot) and a Rubber Band gun designed by “RBGuns” (http://bit.ly/IBM9RubberBandGun). I modified the template from RBGuns to make the styrofoam mold.
Project History & More Info:
The gun is solid aluminum, made from melted down soda cans.
I spent over 100 hours of time, and 7 styrofoam prototypes to make this video. About a third of the time was spent filing and sanding the gun. Each time I poured a casting for the gun, the trigger guard wouldn’t complete all the way through, so I kept making new styrofoam guns, modifying the designs slightly until it worked.
Once I got a fairly clean casting, I put 2 days into filing down rough points, and sanding them smooth.
The gun could use a little more work, and it’s not perfect, but this experiment was mainly a proof of concept that nearly anything you can imagine can be made fairly easily with the “lost foam casting” technique. Overall, I really am happy with the gun though! It weighs 556 grams, and is really quite smooth to feel.
For future projects, I plan to work more with green sand casting. I believe it will leave a nicer finish overall and won’t require as many prototypes to get it right :) Instead of foam, wood plugs can be used to make the molds, or even real weapons for that matter.