Rhino Gas Mask: The Horn

This gas mask was begging for a nasal projection, and so I am obliging it by constructing an exhaust vent reminiscent of a rhinoceros horn.

Here is my concept drawing. The challenge was to make it look mechanical and man-made, while still reminding the viewer of something organic.

I started with a cast resin horn that I've been making for a satyr mask to sell on my Etsy store. I added several rings that I cut out of acrylic sheet (secured with brads), and four pieces of copper ground wire.

The horn will be made of cold cast metal. Like many of my resin mask pieces, it needs to be lightweight, and so I'll cast it hollow. That process is called rotocasting, and it involves taking a regular rubber mold (which can be closed up) and pouring a small amount of resin into it. While the urethane resin is still liquid, the mold is rotated in all directions so that the inside of it gets coated with the resin.

I will do this twice to build up the resin thick enough to be sturdy. In the photo above I've coated the model with white resin to smooth out the inner corners, nooks and crannies. This will make a better mold for rotocasting and will result in a stronger part.