Sunday, January 24, 2010
Since 73% of respondents to my poll on horn direction favored up, I have gone with that.
Saturday, January 23, 2010
Thursday, January 21, 2010
Pictured above is my set up, consisting of a vacuum pump and hose connected to a piece of iron pipe. The bottom of the pipe is closed off, so that when the pump is engaged a strong vacuum pulls from the top of the vertical pipe. Into the open pipe I place the form that I am going to use, in this case a life casting of a woman's face poured in plaster, with a smaller diameter iron pipe protruding from the bottom.
Wednesday, January 20, 2010
A very simple and easy-to-use container for making many types of molds is a paper cup. I have a supply of picnic and popcorn cups in various sizes for just this purpose. For most castings, the paper cup will work also as the mother mold, keeping the mold parts tightly together while the liquid resin cures. For the Rhino canister mold however, I need a rigid mother mold, and here's why.
Due to the fact that I need the cast part to be as lightweight as possible (so that the gas mask will be comfortable to wear), I am going to make it hollow, and the most efficient way to do this is in a rotocasting machine (which holds the mold and rotates it in two different axis at the same time).
I need to clamp the mother mold (and silicone daughter mold) into the rotocaster, and to withstand that pressure I need a rigid mother mold, as the paper cup will just squash. These pictures document the procedure for making this.
The top picture shows the blue silicone rubber mold after it has been removed from the popcorn cup. Below that I am pulling on a 3" diameter nylon stockinette.
I cut the stockinette long enough so that I could double it over. Here I have loosely tied a string around the top.
Now I have pulled the top half of the stockinette back over the bottom half, so that I have a two layers.
Here I've mixed up polyester resin with an activator (and violet dye), and brushed it all over the stockinette until it's saturated.
And here is the final result after it has cured, with the rigid mother mold on the right.
Tuesday, January 19, 2010
The pattern below is the one that I used to make my top hat. For a size large, the width of the crown (from side to side) should measure 23.8". You can print it out and enlarge it to get it to lifesize. The crown has four optional darts (butt seamed), which give it the modified hourglass shape.
The crown joins at the back with a butt seam. If you add a seam allowance you can convert it to an overlap seam and sew it on a machine. The wavy bottom gives the brim the nice shape of down in the front and back, and up at the sides. The dotted line on the brim is where I folded the edge in over a wire.
Monday, January 18, 2010
Pictured above is a No. 43 showing the straps, with the buckles attached to the mask surround and the straps made up of four pieces of leather, riveted (or sewn) together. My second gas mask was Pachydermos, which combined elements of No. 43 and the canisters of my first respirator, the Bad Air Transmutator. It kept the same straps as used in No. 43.
For the Rhino gas mask I've decided to make two major changes in regards to the straps. First of all I have streamlined the pattern into just two pieces, seen below.
And secondly, I've reversed the buckles and straps from the previous versions. On the Rhino, the free strap ends will be pointing away from the face.
Sunday, January 17, 2010
I decided that while I could keep the basic bulky shape of the canister, that I would need to build it from scratch (and not simply modify the original one), in a manner similar to the nose horn, and in the same material. Here is the acrylic and resin model, and the engraved bottom part (made of acrylic and Bondo™), which will be attached before molding and casting.
Wednesday, January 13, 2010
Saturday, January 9, 2010
Here you can see a photo of the mask (minus its straps). The large squat tubular form of the attached canister is quite common, and strictly functional. Given that the horn nose has a strong fantasy element to it, I think that the canister balances it nicely by keeping the simpler shape.
Of course I will gussy it up some, giving it a real Victorian look with leather, and decorative reliefs, etc. Beautiful yet functional. That is the plan for now, always subject to change. Above is my sketch that I'll work from.
Wednesday, January 6, 2010
Tuesday, January 5, 2010
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!
Monday, January 4, 2010
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.
Saturday, January 2, 2010
Once the horn is cast hollow in cold cast metal I'll drill through the eyelets to create ventilation holes in order to make breathing easier for the wearer.
Friday, January 1, 2010
Here is my concept drawing. The challenge was to make it look mechanical and man-made, while still reminding the viewer of something organic.