EVA Foam Armor - Helm




Introduction: EVA Foam Armor - Helm

About: I'm an aerospace design engineer with a degree in plastics engineering, and interested in doing cool stuff. I love building things and problem solving, and I hope you benefit-from and enjoy what I have to offe…

First off, thanks for checking out my tutorial! I'm always open to suggestions and discussion about my process, so please feel free to comment below. Also feel free to comment if you have questions regarding the process, since it's likely my explanations won't make sense to everybody. I make a lot of references to different parts of the helm in the tutorial, so look for captions in the pictures to help understand what I'm referencing.

This tutorial will be one of several I plan to post on making foam armor. This will focus specifically on the helm, and the rest will come as I am able to complete those projects.

Let's begin with some basic information about the materials and processes we're going to use in this tutorial. The primary material I used was EVA foam (Ethylene Vinyl Acetate). This is a polyethylene and vinyl acetate copolymer that is commonly found as anti-fatigue floor padding in hardware stores, and also craft foam in craft stores. Great things about this material are that it is relatively easy to mold and shape, and it's pretty forgiving if you make mistakes. You can use an oven or a heat gun to efficiently mold the stuff into whatever shapes you want. Cutting it requires a very sharp blade, like a new hobby knife, box cutter or, better yet, a hot knife. It's easy to leave cutting marks on the edges of the foam, but those can be either incorporated into the design or even sanded off with a Dremel tool.

To make something like this, you need a simple mold that will give you all of the curvatures you need. Throughout the project, I used a large, thick cardboard tube that was close to the major diameter of my head. Either way, the cardboard tube served as a mold for just about all of the thick foam components I thermoformed, and I would highly recommend it for getting geometrically attractive results. This technique produced a rather circular helm, but the helm can be squished into more of an oval-shape later on if you want. In the following step, I will cover all of the materials you will need to build a helm similar to mine.

Step 1: Materials and Tools


- 1 4-pack of 2' x 2' EVA foam floor padding. By far the cheapest I've found is at Harbor Freight, about $15 per pack when not on sale. Should be around .5" thick, with a textured side and a non-textured side (we just need the non-textured side)

- 2 11 x 17 sheets of black 3mm craft foam. I found these as "Foamies" brand at Joann Fabrics

- Silver Leaf, Antique Gold and Spanish Copper Rub'n Buff. It's a metallic wax that give the metal look to the final part. (I used patina underneath the silver to brighten the final look, but that may not be necessary)

- Acrylic floor polish. I used Pledge Floor Care Tile and Vinyl Floor finish. This stuff helps to improve the look of the finish and helps protect it.

- Acrylic paint. I used Palmer acrylic, but I imagine any acrylic paint will do. You will need Black, and a mixture of red, orange and brown.

-Mod Podge gloss waterbase sealer and Delta Ceramcoat All-Purpose Sealer. I found both of these at Michael's, and only needed small 2 to 4-ounce bottles. Any water-based sealer should work, even Elmer's glue, but that will need to be thinned out with a little water to hide brush strokes.

- Several sheets of printer paper

- Pair of sheep horns (I found mine for around $10 on amazon, but unfortunately they didn't match very well)

- Some small pieces of leather or fake leather



- Hot glue gun and a lot of glue sticks

- Sharp knife (hobby knife, hot knife (basically soldering iron with hobby knife attachment), or box cutter)

- Oven or heat gun (oven recommended, nicer to have both)

- Thick, rigid cardboard tube, and hacksaw for cutting it

- Scotch tape

- Measuring tape, ruler

- Cutting board

- Permanent Marker and Pencil

- Paint brushes

- Mixing containers (just for water-based paints)

Nice to have:

- Rotary cutting tool (like a pizza cutter, but really really sharp and designed to cut fabric. This would have made my life much easier if I had it earlier during the project)

- Clear acrylic ruler

- Dremel

- "L" bracket (metal or rigid plastic) used to assist with drawing line around cardboard tube to cut off circular piece of even thickness

- Miter saw (negates the "L" bracket and hacksaw entirely, and cuts cardboard tube like nobody's business)

- Microfiber cloth

Step 2: Make Your Frame/mold

Having a thick cardboard tube is really important for making a stable frame. Even when hot, the foam will require some pressure to form correctly over the frame, so it must be sturdy enough to handle you pressing down on it. I found my cardboard tube in my school's recycling bin, so unfortunately I can't provide much info on where they can regularly be found, but you could try fabric stores or boating stores (rolls of fabric or fiberglass) to see if they have something similar hanging around.

You want the tube to be roughly the major diameter of your head (the length front to back) or slightly smaller so that it fits properly. If it's a little bit shy, that's okay because you'll end up with enough extra on the sides to slightly deform the helm to fit better.

For this to work properly, you'll want to start cutting from the end that is most cleanly cut and even (if you put a level on it, it should be perpindicular to the tube).

If you have access to a miter saw, this process is far easier. Simply line up your tube under the saw, and cut your tube an inch from the end, to get a one-inch diameter ring. Do this a total of two times. If no miter saw, follow the next step.

Draw a line around the tube about an inch from the end. This is where an "L" bracket comes in handy; you can rest the corner of the bracket on the end of the tube, and use the end as a guide to draw a straight line around your tube. Then cut on the line with a hacksaw to get a cardboard ring of about 1 inch thick. Cut a second ring by repeating the same steps mentioned above.

Next, you will need to cut both rings in half as accurately as possible. One way to do this is by using a piece of printer paper, tracing the outline of the ring and folding the paper in half next to a light so that you can line up the two halves of the circle during the fold. Unfold it and use a straight edge to draw a line splitting the circle in half. Then, line your ring up with the circle and make pencil marks on the ring where they were on your sketched and folded circle. Cut the cardboard at those lines. Repeat this with the second ring. You should end up with four semi-circular rings.

Next, take one of the four ring halves and line it up on top of the cardboard tube, so that it is centered on the tube. Trying to keep this position, hot glue the ring in place. The next ring halves will need to be cut into even smaller sections to line up nicely to resemble a half-sphere. The second ring should be placed perpindicular to the first. Without cutting it, line up the second ring on top of the first and try to place it so that the distance between the ends of each side of the ring is equal. Then mark the lines on the second ring where it intersects with the first. Cut the second pieces at those lines, and glue the sections on with hot glue (throw out the extra middle piece).

The same idea can be now used to create the diagonal supports, but they will need to be cut with a pointed tip to fit as shown in the image above.

Step 3: Making the Skull Cap

The most challenging part of the whole process was thermoforming and gluing the half-spherical skull-cap part of the helm. This doesn't mean it is particularly hard to accomplish, it just took the most revisions to get right out of all the other steps. Don't be afraid to cut pieces of foam larger than they need to be. This may be common sense for some, but it can be easy to overlook. Remember that I am also simply restating what I did to produce the helm pictured in the first step, and there are probably plenty of alternative methods to producing similar results, so don't be afraid to experiment.

First, I made a foam band with consistent 1" thickness. It's easiest to simply cut a strip off the edge of one of the thick EVA floor pads (and carefully removing the puzzle pieces at the edge). The more accurate, the better. Wrap the strip around the circumference of the cardboard tube, mark the intersection of the foam, and cut the excess off. Then wrap the foam back around and hot glue the edges together so the band fits snugly onto the tube. Tip: Add hot glue to both sides quickly, then press together. Gluing both sides of the foam makes the bond much stronger.

The top of the band will be glued to other pieces of foam, so it's best to leave the worse-looking side up and leave the cleaner edge down where it may improve the helm's final appearance. The band I made has two glue seams, as can be seen below. This isn't ideal, but I made it work by evenly spacing them out in reference to the glue seams on the rest of the skull cap. This is important because you will need to cover the seams with other pieces of foam, and by evenly spacing these out they can be strategically covered by thin foam that looks like trim rather than a randomly placed piece of foam.

Secondly, I cut pieces of the dome out into quarters. I had bad luck attempting to thermoform pieces any bigger than this, so this is the largest I will recommend if you're using my method. Using a measuring tape, measure a quarter of the circumference of your cardboard tube. This distance should be roughly the same as the arc length from the top edge of the tube to the center of the half-spherical frame. Add at least 2-3 inches to your measurement, and cut out a foam square with that dimension. The more you add to it, the easier it is to form.

Thermoforming the foam is pretty straight forward, but you must take caution to avoid injuring yourself and burning the foam. I was able to thermoform my foam by preheating my oven to 350, putting the foam piece on the center rack, and allowing it to sit for around 10 - 15 seconds. The foam should be very pliable, but not smoking heavily. I wasn't able to avoid producing a little white smoke, so make sure you have a ventilation fan going above the oven if it happens and avoid breathing any smoke.

Quickly remove the foam from the oven ( I was able to touch it with bare hands, but it would be smart to have an oven mitt handy) and drape it over three of the semi-circular cardboard frame pieces, textured-side down . Press down on the foam at the top firmly, and press against the bottom edge to try to form a consistent circular part. Hold the foam stable for around a minute, and blow on it to help cool it off. This may take a couple of tries, but if you get one wrong, you can usually re-heat it and form it again or do touch-ups with a heat gun.

Using the cardboard imprints on the underside of the foam piece, draw an outline as shown in the image above, and carefully cut it out with a hot knife or sharp hobby knife.

Repeat three more times to make four quarters of your half-sphere. Place them all over the frame with the band to check the alignment and see if any additional trimming or forming needs to happen before gluing. When satisfied, glue them together with hot glue, while keeping them on the frame but avoid gluing the foam to the cardboard frame itself. Start by gluing your first piece to the top of the foam band, and glue small sections at a time until you glue the entire piece down. Using this method of slowly gluing small portions of the foam together, continue the process with the rest of the pieces until you end up with a finished skull cap as pictured.

Step 4: The Face Plate and Back

So you've got a skull cap now, but not much else. This is where it starts to get interesting.

You've got to pick a design for how you want to face plate to look. I used a straight edge to make mine, but I only started by drawing half the face.

Get a standard 8.5" x 11" sheet of printer paper and fold it in half (the fold should be parallel with the short edge). Fold it as accurately as possible by matching the corners and slowly creasing it. Unfold it, and use the crease as a center line for your outline of the face plate. Draw half of it with a straight edge, and use all of the space out to the far edge of the page. Fold the paper, scribble along the rough path where your design is to transfer some graphite to the other side of the folded page. Then unfold again and go over the light transfered lines with a straight edge to make them solid.

Cut the bottom edge of your paper off, and tape the stencil down against the foam using as many tape pieces as possible (so that it doesn't go loose when you start cutting).

Slowly and carefully cut through the paper into the foam with your hot knife or hobby knife. It's important to cut firmly, but don't try to cut all the way through if there's a lot of resistance. You only need to cut enough to transfer the pattern to the foam, where you can finish the job later without the paper stencil. TIP: A nice effect is to cut out the eye holes at an angle so that the shallowest part of the opening is facing the outside. This reduces the visibility of imperfections from cutting the foam.

Preheat oven to 350, leave the foam in the oven for 10-15 seconds (or as long as it took when thermoforming the other pieces of foam) and carefully press it over the tube. Be sure to keep the top edge aligned with the rim of the tube. Hold it for roughly a minute to allow it to cool properly.

After thermoforming, the face plate can be glued to the bottom rim of the skull cap. Make sure to line up the center of the face plate with a glue line on the skull cap to make it easier to conceal the glue lines with trim pieces (if you're going with a design like the one I did). My particular design ended up looking weird with the 1-inch band in place, so I had to cut off the section where the face plate would fit (which would make the face plate rest higher on the helm). I then simply glued the face plate back onto the skull cap where I removed the foam band from. If you do this, remember to figure this in when measuring the thickness of the rectangle in the next part.

The back plate I made was simply a rectangle. Using a thin, rectangular piece of scrap foam, I held one end at an edge of the face plate, curled it around the base of the skull cap and made a mark on it where it intersected with the other side of the face plate. This was just to get an accurate length for my rectangle.

I cut the width of my rectangle to be equal to the distance from the top to bottom tip of my face plate, and thermoformed the rectangle in exactly the same way I did the face plate.

The rectangle (back plate) can now be glued onto the skull cap and to the outer edges of the face plate.

Step 5: Add the Trim

This is where your own creativity comes into play. Besides looking good, the thing your trim is best at is covering up glue lines. When adding the trim, try to glue the edges, but use a small bead of hot glue to reduce glue seepage from the edges (a little can be okay though, and could be incorporated into the weathering effect later).

The first thing I did was cut out 7/8-inch thick strips of black 3mm craft foam. I carefully measured around the helm, and added roughly an inch to each length to account for error. Cutting these is easiest with a rotary cutting tool, cutting board and straight edge, but it can be done with a hobby knife rather than rotary cutting tool. A big paper cutter would probably be even better.

You will find times when you need to decide whether to cut the segment to fit or to overlap. From my experience so far, I would recommend taking the extra time to cut the strip that would overlap another, because in my opinion I think it looks a bit better. I recommend gluing the strips where you need them first, then carefully cutting them on the helm itself to fit. The heat from the hot glue tends to warm up the foam to a point where it stretches easily, and your dimensions will not be as accurate as they were on the cutting board.

 Using the stencil from step 4, I cut a second face plate (black, pictured above) out of 3mm craft foam. This piece may not be necessary, but I liked the way it looked at the time. Be sure to use a lot of tape, and follow the same procedure as with the thick face plate. I cut the eyes out slightly larger so that they showed some of the material behind it. Glue the black face plate on with hot glue being careful to line everything up properly.

Step 6: Add the Horns (optional)

This step is entirely optional if you like the look of your helm with no horns or simply can't find a set that fits your tastes. I don't have any pictures of the process unfortunately, but adding them to the helm is relatively simple. Since all horns will be different, I have included a few pictures to demonstrate the concept of the process with a flashlight I had laying around. I will continue assuming you will be using two horns.

First, find some scrap foam with enough space to fit the base of your horn, plus at least a half-inch worth of edge space surrounding it.

Press the horn firmly into the foam leaving a clear indentation in the foam where the horn used to be. The pictures above demonstrate this with the flashlight. Mark the outermost line with a permanent marker to ensure that the foam doesn't rebound and loose the indentation.

Cut the foam just inside the permanent marker line to give your horn a snug fit into the piece of foam.

Now draw around the horn in the foam where you want the outer edge of the foam to be. Remember that the larger it is, the more surface area you'll have to glue to the helm. This is really important for making them stay permanently attached to your helm.

Cut out the piece of foam on the line you drew. If you're satisfied, you're now ready to wrap it in a piece of leather or fake leather. The leather trim can also wait until after you glue the horns on if you prefer (this helps if you're concerned about getting paint from later steps on the leather as I did.. I had to clean them a few times).  I wasn't too picky with how mine covered the foam, but it would undoubtedly look better if I put more work into it. I basically cut a strip of fake leather to fit around the outer edge of the foam piece and hot glued it in place so that it wrapped over the outer edge. If your leather is too thick to bend easily, you want to consider leaving it on the outside only so that it doesn't offset the horn from the helm and keep the glue from sticking on the inside (or, of course, get some thinner leather).

Next, put some glue on the inside hole of the foam, and press in your horn to fit snugly. be sure that your horn is slightly below the bottom edge of the hole so that you, again, don't offset the foam piece from the helm when it comes time to glue it to the helm.

Repeat the previous steps with your second horn, don't glue it to the helm yet. It's better to have two when you want to place them so that you can mark your locations easily.

Choose a suitable location for the horn that will be easy to mirror on the other side with your second horn. Place both horns on the helm and try to eyeball them as best you can and line them up with landmarks on the helm (corner of the eye holes, etc). When satisfied, have someone else mark the circumference of the horn attachment with a fine tipped marker while you're holding them in place (assuming you're painting over it later).

With the locations marked, use your hot glue gun to quickly put glue on the helm and on the underside of the horn. This can be hard to do quickly, so focus on only the main points of contact but try to get as much area covered as possible. Hold the horn on the helm for at least a minute or two.

Step 7: Seal the Foam

I can't stress enough how important sealing the foam is to the final appearance. Skipping out on this step may be okay if you're not too concerned with the appearance and would rather complete it faster, but this step greatly improves the finish of it and makes it resemble metal a whole lot more than it would with only a coat of metallic wax.

The main purpose of this is to seal up all of the open foam cells that sit at the surface and fill in roughness to make it smooth. While it may look like there aren't any there, this is what makes the foam have a dull finish, and you'll quickly see how different it looks after a few coats of sealant.

Ideally, you'll start with a sealant with relatively low viscosity so that you can fill in small pores and not leave brush strokes. This is a good way to apply a first few coats of sealant. If you decide to, you can then apply more viscous sealant to make the process go faster, but you must be aware of your brush strokes and be sure to brush in a single direction. This can give your "metal" the appearance of grain, but only if your brush strokes are very fine.

For the first sealant, I used elmer's glue mixed with water. About 2/3 Elmer's glue and 1/3 water. You can refine the mixture if you want. I put around 5 coats of this stuff on there, but it was pretty quick considering brush strokes didn't show through really well. Even so, I still brushed in a single direction (it's easiest just to brush along the length of long, skinny strips). Make sure to seal all of the foam.

For the second and final sealant, I used a mixture of Delta Ceramcoat All Purpose Sealer and Mod Podge Gloss. It was a 1:1 mixture. If your brush strokes are becoming too easily spotted, you can either add some water or add a bit more all purpose sealer (less viscous than the mod podge). Be sure to cover all areas, and again be sure to brush it on in a single direction. Repeat at least 3 times. If you brushing direction and coat thickness are consistent, the more coats the better.

Step 8: Paint the Helm

Remember when I said thermoforming the helm was the hardest part? Whether or not I'm correct depends on how much of a perfectionist you are. Painting was the most fun in my opinion, but it can also be aggravating if your results don't look good quickly. Remember that it's really easy to cover stuff up if you make a mistake, and if you've made some mistakes that have gouged the foam or made other aesthetic defects, remember that painting is your way of making them look intentional. I integrated a lot of my defects into the appearance by making them look like corrosion, battle scars, etc. Also remember that you have your nifty frame which just happens to be a perfect place to place your helm while you paint.

I started by deciding what types of metal I wanted my helm to have. I decided to make the primary thick part of the helm appear to be like steel, and the trim to look like bronze.

This may no be necessary, but I started by applying Patina Rub'n Buff to the steel-like parts. This is a bright blue metallic finish, but it was intended to help the silver appear brighter. I think it helped, but adding an extra layer of silver might make the patina unnecessary. You can apply the rubnbuff with your fingers (I used gloves because it can be a pain to wash off) or a brush, but make sure you wait to paint the trim until after the main part of the helm is done so you can cover up paint smeared on the trim later on. When applying the rub n buff, don't apply too much at a time. Go easy, and smear little bits at a time until you can't smear it any further. A little goes a long way. Also remember to smear it in the direction of your brush strokes. Use a microfiber towel to buff the excess flakes and wax bits off after a half-hour or so, this also helps it shine up. Be sure to buff between each coat.

If you applied a patina to the steel parts, apply a couple layers of silver leaf to the helm allowing a couple hours of drying time in between. Thin layers will dry quickly and won't leave bumps and other imperfections.

Next, apply the Spanish Copper Rub n Buff to the trim. This will appear dark and almost wood-like (especially with the mild brush strokes). Two to three thin coats of this will be needed.

When that is complete, dry brush (don't try to cover the whole thing) antique gold along the center of each trim piece and randomly fan the brush out to create the streaking effect you see in the trim. I made sure to do this on a piece of paper first to get rid of gobs of paint, then I put the brush on the helm to make sure I wasn't smearing on too much paint. This takes a while, but only one coat is needed (unless you want to add more in other areas). If you don't like the way part of it looks, try to incorporate the mistake or paint over it and do it again.

As a final touch to the painting, I painted some of the exposed foam edges with flat black acrylic paint. This was more for me as opposed to the appearance, because I intended to wear this outside in the sun and didn't want silver eye holes reflecting sunlight back into my eyes. This can also be done on the foam pieces connected to the horns if there's exposed foam there too. This is, of course, optional and can be replaced with whatever colors you think will fit with your style of helm.

The last step before weathering is to apply a final coat of polish to seal the wax. For this I used a really low viscosity acrylic floor polish (Pledge, pictured above), and applied several coats. I ended up using the cloth to apply it, and this worked since I made sure the cloth was pretty well soaked with polish (enough so that I wasn't wiping any off). Let it dry between coats. Doing this several times will improve the appearance and will keep the Rub n Buff from easily wiping off when touched.

Step 9: Weathering and Finishing Touches

The best advice I can give is to research the metal you want your helm to appear like, and look at how it typically corrodes. Observe the colors it produces and try to mimic that in your paints. If you have a corroded piece of steel or bronze for reference, even better.

After my helm was painted with Rub n Buff, I decided to add weathering to the steel since it looked a bit too bright. The bronze appeared weathered enough from the antique gold wax, so I left that alone.

The way I did it was with a microfiber cloth, a paint brush, acrylic paints and some water.

First, I mixed some red, brown and orange acrylic paints until I I came up with a good rust color. This was completely improvised, so unfortunately I don't have mixing ratios for you. You'll have to mix small amounts until you get the color you're looking for. Also be prepared to weather the whole thing at once so that you don't have to recreate the same color over again.

First, I liberally painted some of the rust color into the corners and a a little onto the main part of the helm. If you take your time, do this to half the helm, then come back with a  damp cloth and wipe up the paint beginning where you started with the brush. The idea here is to paint excessively in areas that are hard to reach, then wipe up the excess paint with a damp cloth before it dries completely. If you think about it, it kind of makes sense for the real world because you want corrosion to appear to build up in areas where it's not easily brushed off during use.

Secondly, I carefully dabbed a small amount of paint onto my cloth and dabbed (stippled) the paint onto the fake steel parts. Be careful not to smear the paint, you want the paint to appear as tiny, random dots. Vary the way you dab the cloth against the paint and against the helm to introduce randomness so you don't inadvertently end up with patterns. If it looks too bright, wipe it up and try again.

If you're satisfied with the appearance, let it dry. You're done!

Step 10: Upcoming - Armor

I am currently at work on my next project which is to add pauldrons and a breastplate to the helm. Stay tuned to see what comes up!

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7 years ago

Can you send a link or photo of the heat gun? What about a hair dryer? I have a heat gun for heat embossing, will that work?


7 years ago

So what is the shape of the quarter panel that you used for the dome? I've been trying to figure it out all day and I've use so many sheets of paper trying to get it right before using my craft foam/eva foam... :/


9 years ago

My project was a success because of your post and I wanted to let you know that. :) Keep posting, I would like to see what you can come up with. I recommend a wagon and horse prop or maybe a building prop so we can learn how to make scenes. The more reusable, the better. I spray painted mine and let the fumes wear off on a nice day then I sealed it. It was dry within the next 2 hours (roughly) and then I put a clear sealant on top of my metallic paint to make it resemble the looks of metal even more.


Reply 9 years ago

Awesome! I'm really happy to hear that. I dropped the ball on getting a lot of these projects done when I moved from college to a full-time job, but hopefully I'll be able to get some more instructables posted some time in the near future. Thanks for taking the time to let me know; it's encouraging to hear that my work has inspired others.


9 years ago on Introduction

I wanted to say thank you for posting this-- I've made my own armor with it! <3


10 years ago on Introduction

Sweet job. I have made a pretty nice papier mache helm, but I think I am going to try an EVA foam one to see how those results go. I am hoping the foam will create a little smoother to work with initially.


10 years ago on Introduction

Where did you get the horns? I was planning to make a sinister viking type helmet with similar horns but have no idea where to find them.


11 years ago on Introduction

i used to wear a helmet like that, but then i took an arrow to the knee!


11 years ago on Introduction

Did anyone figure out where to get the card board peice he found in the trash?


Reply 10 years ago on Introduction

It is a sonotube. You can get one at any home improvement place. It is used as a form for concrete poured-in-place pillars.


11 years ago on Introduction

Dude, this is sweet. I am totally going to make one or two of these.