Rhino Gas Mask: Finished Canister

The Rhino canister model with the finished cold cast aluminum one.

The model weighs 392 gm, while the hollow cold cast version weighs a mere 91 gm (3.2 oz)! The wearer won't even notice it's there.

Rhino Gas Mask: Eyepieces

I wanted to do something new with the eyepieces for this mask, different from what I'd done before. In the past I've used camera lenses, and several fabricated eyepieces, but they have all been circular. The rubber German gas mask that I pulled the pattern from also has round eyes, but after taping and making the 2D pattern, then cutting it out of leather and reassembling it as a 3D mask, the eye openings were no longer round. I could have easily inserted round eyes into the leather mask and it would have conformed seamlessly, but I felt that I had already done enough round eyes, and in this mask they even made it look a little goofy.

Thus I decided to go with the organic shape that the mask naturally took (seen in the shape of the clear lens above). Then I thought "Why leave the perimeter smooth?" and opted instead for a mishapen octagon. And one more innovation: Adding brass crossbars to protect the lens from breakage.

Above are the individual pieces: The base part cast in black resin, the clear acrylic lens, the cold cast aluminum cap, and the five brass rods.

And here is the assembled eyepiece for the left eye. The right eyepiece is a mirrored image. I fabricated both the base and the cap out of sheet acrylic. To the cap I added eyelets and machine screws, then molded it and poured it in cold cast aluminum. Now that is a different looking eyepiece!

Rhino Gas Mask: Cold Cast Horn

I've now cast the rhino horn in cold cast aluminum. Below you can compare the model (on the right) with the finished piece (on the left).

Designing a piece of art such as this requires being able to look at the model—here made of an unsightly conglomeration of resin, acrylic sheet, copper wire, metal eyelets, and brads—and see the finished horn, in all its beauty. (You do think it's beautiful, don't you?) That is the wonder of resin casting, and especially cold cast metal casting.

Cold cast is nothing more than mixing a very finely ground metal powder (in this case aluminum) into resin. Once it has hardened, I sand the surface of the casting to reveal the aluminum beginning with 180 grit, and continue with finer grits all the way up to 0000 steel wool.

The final step is polishing the piece with a Dynabrade rotary buffer, using a foam pad and compounding liquid. That final polishing is the key to getting it to shine.