Costuming 101: Constructing Waist Armor

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Another edition of how to create wearable Stormtrooper, other, body armor using recycled HDPE plastic chemical barrels.


Costume Armor Protection for the Waist

We learned how to make a basic 'chest-cage' in the first tutorial Fantasy Armor Created from Recycled Plastic Chemical Barrels and the follow-up Creating Wearable Armor / Upper Leg Protection. Methods learned in these lessons included the use of an electric jig saw, a propane torch for heating and bending of the plastic carapaces, and use of the pop-rivet tool. These tools and methods of assembly will be used in this build and it is assumed that the builder understands their use.

In this edition we shall make a locking and removable covering for the waist and groin area. We will also size it to work in conjunction with the Upper Leg Covers created in the previous article.

This Waist Cage as I have named it shall be a hinged 'clam shell' design that is comfortable and easily removed by the wearer to make getting dressed or undressed easier. Making the waist covering is probably the easiest part of creating HDPE armor as it allows for the greatest leniency of design.

To build the armor that will fit around the wearer's waist we begin tracing a pair of the wearer's underwear laid flat onto white poster-board. This undergarment has the approximate what that we require.

We extend and expand the crotch several additional inches to provide excess, as well as extending and flaring the left and right hips slightly both as depicted by the red dotted lines (refer to image.)

Create Waist Cage Template: Cut out two of these in HDPE Plastic

The basic shape of the armor for the hips and waist; traced underwear on poster-board with extensions at the crotch, and at both sides at the hips

Holding the cut-out poster-board pattern to the wearer, we test-fit the template for size. It should cover or at least meet the top of the horizontal belt-line, extend slightly below the top inseam (crotch) and the side 'wings' over the hips should wrap around the waist slightly covering the topmost outer-seam of the wearer's pants. There is excess template (and thus, carapace material) that will be trimmed off later.

It is easier to make an over-sized carapace smaller and it is impossible to make an under-sized carapace larger so it is generally a good approach to always plan the template and cut-out carapaces have overlap regions, excess plastic that can be trimmed to size and symmetry later.

Although the FRONT waist cage and the REVERSE waist cage halves will be cut and worn differently, we use the same pattern to draw and cut-out TWO of these from our 55-gallon HDPE plastic chemical barrel.One of these carapaces shall be lightly trimmed to size while the other shall be more grossly cut-down to size. For what it is worth, I usually saved any 'trimming' that was the size of my palm-&-finger spread or larger for possible future needs. You never know when or for what you will require a 4 or 5-inch square chunk of this HDPE plastic when constructing these types of armor.

Heat and Bend Hip Wings to Form Waist Cage Halves

Using the propane torch and a tub of cold water, heat each of these yellow oval areas one at a time and bend to form a curvature. The two bends should wrap tight around the wearers waist.

In this overly-simplified sketch, with the propane torch and a cold water basin (bath tub, etc.,) heat approximately the yellow oval areas one at a time and bend to form the curvature of the wearer's waist. Immerse in cold water to 'set' the desired bend. Repeat on the opposite side. Repeat this process again on the second carapace half.

Little or no real 'on-body' measuring is require for these while heating-&-bending as ultimately the halves will be torsioned to fit. You want to make each of these two halves be a 'snug fit' when they test-fitted to the wearer's waist. When both halves of the waist cage are hinged to each other in later steps with an adjustable snap strap, they will be a snug and perfect fit.

This may look daunting but making these waist cage halves are some of the easiest carapaces to make in wearable body armor. While HDPE does not readily lend itself to 'cold bending' to form a circle or curvature, a bent-curvature can be 'relaxed' to a large, rounder oval fairly easily. Since these two halves shall be measure to fit together, the main 'adjustment' when wearing is dictated by the position of the snap buckles.

Heat and Bend the Crotch Extensions of your Armor

Heat the yellow oval regions, bend & hold while immersing in cool water to set the plastic in the shape depicted.

Heating the yellow areas with the propane torch until pliable, gently bend the crotch extensions as shown and immerse in cool water. The exact shape and sizes vary, but if the plastic carapace is tall enough the correct height can be compensated for by trimming the top edge of the plastic at the belt-line.

While these two carapace sections are identical, the FRONT shall be larger to cover the groin region and the REVERSE half shall be trimmed somewhat to just reach the base of the spine. This suggests the appearance of protective armor and yet will allow for comfort in both wearing and sitting position.

I continue to stress the importance of 'comfort and easily removable by the wearer' in all my armor constructs.

Attaching a Hinge and Locking Buckle to the Waist Cage

Sizing for fit, attach a small door hinge to one side of the waist cage and a locking plastic belt-buckle to the other side. When worn and clasped, the waist cage should be snug and not slide down off of the hips

By carefully cutting-off length of the 'tails' at the hip level, the two carapaces are roughly paired to form the 'waist cage.' You want the hinged section to meet close at the top outer inseam of the wearer's jeans, and the locking snap belt buckle on the other side should have an overlap or under-lap when drawn one over the other.

The waist cage is now wearable, but additional 'size fitting' may be in order. The top-most edge probably needs to be cut to be horizontally true, and be just above the intended wearer's belt-line. Some sizing around both the crotch and rump area for comfort and modesty are a certainty.

Next we have to make this compliant with the Upper Leg Covers that we made earlier, for likely the Waist Cage will now interfere with the top-edge of the leg covers.

Rock, Paper, Scissors?

What happens now when we try the basic Waist Cage on with the Upper Leg Covers that we made in the previous tutorial? Very likely there will be an overlap as shown in part "B" below.

By trimming the Upper Leg Covers as shown in image part "C", we end up with an arrangement as shown in the last image, "D" so that there is no overlap or impingement.

The upper leg covers that we previously made need to be sized to not interfere with the waist cage unit, as depicted.

When you get the Upper Leg Covers and Waist Cage sized, trimmed and symmetrical, it can be 'decorated' with add-ons to suggest various components. Some of those 'palm-sized' sections of saved HDPE plastic can be riveted to the exterior to suggest thicker armor plating, access port or similar trim effects.

At this stage I shall just try to find actual images to give you ideas and inspiration of what can be done. What you do with your armor and how you decorate it is up to you. The armor can be spray-painted with paint made for plastics. Any visible magic marker lines should be removed first using an ammonia cleanser spray, washed with soap and allowed to thoroughly dry. Chemical in the magic marker will cause any spray paint that comes into contact to warp, bubble-up and peel over time.

the opened waist cage. Note the hinge in the middle and the plastic snap-latch buckle on either end that when worn, closes the waist cage around the wearer

While this inside views of the opened-up Waist Cage does not look like much here, when worn around the waist in conjunction with the rest of the armor it achieves the effect desired.

As you can clearly see from the image of the actual waist covering unit, it really does look much like a pair of personal briefs albeit cast in hard HDPE plastic.

I am still searching for suitable pictures of the actual armor as it looks when worn upon the body.


Rae Morvay
Posted on Sep 2, 2010
Pinar Tarhan
Posted on Aug 27, 2010