Ronin: Respirator Gas Mask Tutorial

This tutorial is adapted from a workshop I lead at the Nova Albion Steampunk Exhibition last March in northern California. I am attempting to make this easy to follow and doable even for the novice leatherworker. The pattern pieces are all to scale, and include holes for rivets, slits for thread, holes and slits for buckles and a button stud, plus decorative openings for ventilation.

Materials and Tools needed:

2 square feet of vegetable tanned cowhide, 3-4 or 4-5 oz weight.

Awl or lacing fork

1 stitching needle (Tandy 1195)

4 pieces of 32” long waxed thread

22 medium rivets (Tandy 1373)

4 rectangle rings ¾" wide (Tandy 1137)

2 buckles ¾"

1 button stud

Hammer for setting rivets

Anvil or steel plate

Heavy shears for cutting leather

Scissors for trimming thread

Screwdriver for setting button stud

Leather dye or wood stain or shoe polish to color leather

Contact cement to glue leather

Enlarge the pattern so that the ruler marks are one inch long.

Assembly

Wet these four leather pieces: Front, two cheeks and surround.

Stitch cheeks to the front with needle and waxed thread using a running stitch. Front goes on top of cheeks. Match up colors as shown on diagram, ie. green to green, pink to pink. Begin at one end from the flesh side of the leather (inside of mask). Stitch to the other end going through every hole, then turn around and come back to beginning. Tie two thread ends in a square knot on inside. Trim thread to less than ¼’. Sew the other cheek on in the same manner. After both cheeks are stitched onto front, place damp surround over mask with pointy end facing up. Take two sets of rivets (male and female) and attach the surround to the mask through the center holes, one on each side. Press rivets together with your fingers till they snap into place. Don’t hammer flat until later. The rivets will keep the parts aligned while you stitch them together. Stitch the bottom part of the surround to the mask using the same running stitch as before. Tie a square knot, then stitch top half of surround to mask. Tie off, then hammer two rivets flat. Attach two rectangle ring straps to sides of mask with two rivets each. Pointy part of strap goes up. Place four rectangle rings onto straps (one per strap) and fold straps back, aligning the rivet holes. Hand place the rivets and hammer flat.

Attach two head straps to each other using four rivets. The free ends go to outside (grain side). Take two buckle straps and attach to ends of head straps. Round end of buckle straps goes to inner holes of head straps. Hand place rivets. Place two buckles over free ends of buckle straps. Fatter end of buckle goes to outside. Place rivets through two buckle strap holes and then head strap holes. Hammer all four rivets flat. Shape mask to face and allow leather to dry.

Attach button stud with screw to left lower side strap. Mark where button stud cover goes behind button stud and attach with contact cement. Fold upper and lower side straps over rectangle rings and rivet.

The two resin canisters as shown can be purchased at my Etsy shop, or you can create your own. Mine attach to the mask using a bolt and washer. Attach two canister bolt covers to inside of mask with contact cement.

Buckle upper side straps and adjust to your head. Attach lower side strap to button stud behind your neck.

Participants at the Nova Albion workshop received a kit of most of the parts. I still have a few kits available which I am selling for $49 and include everything except dyes and contact cement.

If any part of this tutorial needs clarification please make a comment, and I will attempt make it clear.

The kits are all sold, but you can buy the resin canisters at my Etsy store.

©Tom Banwell Designs 2011

Ichabod: The Pattern

Now I'll make the patterns for the leather pieces (which will support the three cold cast parts).

I begin by marking where the seams will go on the plasticene with a Sharpie™ felt tip pen.

After sealing the clay with a coating of pink urethane resin, I cover it all with strips of masking tape. The resin is necessary as masking tape won't adhere to the clay.

Once I am satisfied with the pattern pieces I use an Xacto™ knife to cut off the individual masking tape patterns.

Now I test my pattern by cutting them in a thin cardboard, stapling and taping the different parts together. All looks fine, so I will proceed to the next step.

And finally I cut the pieces out of leather and stitch them together. The eyepieces fit nicely, however the beak opening is too large. I will have to adjust the pattern and try again.

Ichabod: The Beak

I have built the beak with the same sort of relief decoration as the eyepieces.

This is the beak in progress with the lasered relief applique in the background.


Here is the final cast beak, showing both the side and bottom view, in cold cast aluminum.


And here is the beak on the plasticene sculpt, giving an approximatation of the final mask.

Ichabod: Eyepiece Cap

I've made the eyepiece cap (the ring that keeps the lens in place) with a decorative design similar to the eyepiece itself.



Here—left to right—are the model, the unfinished casting, and the polished cold cast aluminum cap.

And this is the eyepiece with cap in place on top. I am quite pleased with how it is looking.

Ichabod: The First Sculpt

With the eyepieces done I move on to sculpting the mask in clay.

I place the two eyepieces onto the face form and start adding plasticene, which I've warmed in the microwave oven to soften it.

I build the beak up to where I think it should be. I'm not concerned about getting it smooth at this stage. I just want to get the proper proportions.

I use my clay tool to remove a layer of plasticene at the bottom of the beak, where the leather will lie over the resin.

And I cut off what will become the resin beak, and prepare to make an RTV silicone rubber mold of it.

Once the mold is cured I cast it in urethane resin and proceed to refine it. Sanding down the resin is easier to do then smoothing out the clay, and achieve a nice clean surface.

Ichabod: The Finished Eyepiece

After staring at the eyepiece prototype for a few hours I have decided that the foam relief is too pronounced, so I've replaced it with a much thinner material.

The new prototype is on the left, the cold cast aluminum part just out of the mold is in the middle, and the polished eyepiece is on the right. The cold cast is a dull gray until it is sanded to reveal the metal powder and polished. Next I will move on to the sculpting of the mask in clay.

Ichabod: Molding the Eyepiece

Continuing with the Ichabod eyepiece, I seal the outside with Bondo™ auto body putty so that the mold material won't leak in between the individual pieces of acrylic.

I hot glue the model to a small piece of Formica. Here I am hot gluing a paper popcorn cup down around the model to contain the rubber.

This is the model, cup and wooden dowel (to make it easier to demold and to save on rubber) ready for the silicone rubber.

The silicone rubber RTV (room temperature vulcanization) is ladled out with a spatula.

First I weigh out the white rubber base......

.....then I weigh out the dark blue activator, which is 10% of the base weight.

After mixing it completely with the spatula, the silicone mix is placed into a vacuum chamber to boil out any excess air. This picture shows the rubber mix boiling away (at room temperature).

Once it is vacuumed (deaired) the silicone rubber is poured over the model.

The next morning I demold the eyepiece, and cast it in a charcoal colored urethane resin. I sand smooth both the interior and the exterior of the casting.

Now for the decoration. Rather than add screws or bolts as I have with earlier steampunk eyepieces I have decided to add a design in bas relief. First I draw out the design with a black Sharpie™ on white paper, then scan it. Bringing it into CorelDraw™ I vectorize it and clean up the lines, then laser cut it out of green card stock to check the fit onto the eyepiece.

All looks well so I proceed to laser cut a thin piece of foam with mirror images of my design. The pressure sensitive tape on the back allows them to be attached and ready to mold.

Ichabod: A New Plague Dr Mask

I have decided to create a third version of the plague doctor mask, in addition to the classic historical style, and the steampunked Dr. Beulenpest, shown below.

I have had several requests for an extended beak, and that will be one of the modifications in the new mask. In my initial sketches (shown below) the mask reminds me of a crane, and so I am calling the new piece Ichabod, in a nod to the 19th century author Washington Irving and his Legend of Sleepy Hollow.

Before I can sculpt the new mask in clay I'm going need to build new eyepieces for it. Here I have lasered out several rings in acrylic sheet, which will be aligned and assembled using the brass rod. I slide each piece in the proper order over the three rods and use epoxy cement to hold them together. A stationary belt sander is used to turn the stepped bottom into a smooth angle. And here I've cemented a flange on the bottom to keep the eyepiece in place on the mask. Next step is molding it in silicone rubber.