EVA Foam: the First Armor Build

Build guide 🛡️ · Workshop crew · Nov 2026

The foam

EVA foam comes in thicknesses; the build's vocabulary is millimeters: 2 mm for fine detail and straps, 5 mm for the main plates, 10 mm for bulky forms. Yoga-mat "floor foam" works for practice; craft-store "foamies" are thin craft foam, the pro-grade sheets are denser, hold bevels, and take heat without melting into pancakes.

Cutting & bevels

• Sharp blades only, dull blades chew foam; change the blade per session.
• A bevel is a cut at an angle: two pieces whose edges are beveled opposite directions glue flat into a smooth curve, the seam trick of the whole craft.
• Templates printed at true size (the build sheets) trace with a white marker; cut once, not twice.

Heat forming

Heat gun, moving the whole time: the foam softens, you hold the curve, it remembers. Ventilate, wear gloves, and never heat an assembled piece with glue inside before reading the glue's temp rating.

Glue & primer

• Contact cement: coat both faces, wait tacky, join once, do not reposition. Outdoors or ventilated.
• Primer: Plasti Dip or gesso makes the foam paintable and seals pores; 2–3 light coats beat one heavy one.

Paint, briefly

Flexible paints or flexible-primer systems (a rigid paint cracks at every bend). Washes in recesses, dry-brush on edges, masking for hard lines, and photograph before the con: the paint looks different in hall light.

A bracer, worked from the app's numbers

One forearm piece, end to end. Measure the wearer: wrist 19 cm, forearm 26 cm at the widest, plate height 16 cm. The app's tapered bracer tool is built for exactly this piece — feed it the measurements and it lays out the flat template arc, wider at the forearm end, and the taper math is the tool's job, not guesswork. Cut the arc from 5 mm dense foam, bevel both seam edges at 45°: on 5 mm foam the app's bevel setback tool puts the cut line back ≈5 mm, so two beveled edges glue into one flat curve. Two straps of 25 mm elastic, cut about a hand-width over the wrist measure so the velcro has land. Contact cement on both faces — the app's Paint & adhesive coverage tool counts two faces for cement and adds its 20% absorption allowance for foam — join once, tacky, no repositioning.

Three sessions: one for the plate, one for straps and fitting, one for primer and the metal paint chain above. Log the hours and spend per session on the build log sheet; the planner carries the piece as one board tile.

Fixes