EVA Foam Crafting – Part 1
EVA foam is an amazing crafting material which shines in particular for making armour and props on a budget. This guide will cover many ways to work with foam!
(This article was written from a British perspective, therefore products that are available exclusively in America/Europe I won’t be able to cover and prices/locations are for this side of the pond.)
What can you make with foam?
Sakara Costumer and Model – Photo by Magic Bean Studio
Punished Props – No Photographer Credited
My own build made from EVA Foam!
What is EVA foam?
A lot of people have heard of ‘foam’ armour but don’t know what type or where to get hold of it. EVA foam is used to make yoga mats and floor mats, and also comes in thinner varieties sold as ‘craft foam’.
The most common types of EVA foam are tiled floor mats (10-15mm thick), rolled yoga mats (7mm~ thick) and craft foam which is 1-3mm thick. Here’s what the different thicknesses look like:
You can buy it online by searching ‘EVA foam mats’, but also check your local home stores and supermarkets because they may stock it for a lot cheaper, and you won’t have to pay for postage!
At my local home store EVA is priced as follows:
7mm Yoga Mat 4ft by 7ft – £17.
4 interlocking multicoloured mats – £3.
8 black interlocking mats – £8.
You can get thin craft foam from Hobbycraft in A4 and A3 sizes for 50p-£1 a sheet.
Do not get EVA foam confused with any of these types of foam!
Why is EVA foam awesome for making armour?
-It is LIGHT so it won’t weigh you down like metal or fibreglass.
-It is FLEXIBLE and DURABLE.
-It is SANDABLE so it can be carved, polished and made to imitate other materials.
-It is NON-TOXIC unlike materials like fiberglass so it’s totally safe to work with in your own home (or cramped uni accommodation!).
-It is CHEAP. This is the big one. EVA is much cheaper than most other armour making materials.
Patterns and Design
Choose the thickness of foam that’s appropriate for your piece. Thinner foam will bend more easily, but will be flimsier, whereas thicker foam is more durable and holds its shape better, but may not be flattering for more figure-hugging designs.
Decide on your design and get some good references, or find a pattern! If you’re just starting off, try these patterns for Commander Shepard’s armour: http://www.julianbeek.nl/blog/ The gun pattern I am using is from Punished Props. When cosplaying, it’s best to save time where you can, so I used this pattern because it is already perfect for what I need.
A good way to make patterns is to wrap yourself in cling film and then papers tape, then trace the shape directly on to your body. You can then cut out the pattern from the tape! Alternatively you can just make measurements or design the shapes onto a mannequin or duct tape dummy.
If the piece you’re making is a complex shape or it doesn’t conform to your body, try making a mock-up out of newspaper and tape first! To make this shoulderpad, I tried several paper mock-ups until I was happy with the shape. You can then use the paper pieces as your pattern.
Cutting and Sanding
Foam can be worked with basic sandpaper, but the best tools to get if you’re willing to invest are a Dremel and a belt sander. You can get a Dremel for £20-£70 depending on the model that you buy and it comes with various attachments.
A dremel is great for any detail work and also for sculpting the foam. Here I’ve used the basic sanding attachment to shape out the handle for my gun.
To cut, you can use a scalpel, stanley knife, scissors or a hot wire, depending on the thickness of the foam. If you have access to one, a band saw is also good. Whatever you use make sure it is sharp!
Once you’ve cut and sanded your foam into shape, you will probably need to clean up any edges or details. To sand the edges of this gun, I clamp the piece in place and use the dremel sanding attachment. You should use a mask and goggles for this because a lot of foam dust will be generated, and it will also stick to you and your clothing.
To score lines in foam you can also use your dremel, alternatively you can do this with a scalpel, or if it’s thin foam you can just use a biro. This is great for detail work! For this gun I need to sand down the pattern on the underside of the foam, in order to have a flat surface to bond together. You might also need to do this if your foam is too thick, or if both sides of the foam will be visible. You can sand the foam down with a belt sander (for large pieces) or the dremel (for small pieces).
Another method for detail work is to use thin craft foam to make panels or small details, then glue them onto the main form. This is how I created the shapes for the top of my gun:
Heating and Bending
One of the great advantages to foam is that it can be heated to bend into curves. The foam is heated, bent and then retains its shape after cooling. To heat-form foam you will need a heat gun. You can heat-form using the oven but I won’t be covering this technique, as I find it’s much easier to control heating and bending your foam with a heat gun and it’s much harder to accidentally melt the foam (and you won’t ruin your oven if you do).
You can get these in home stores or online for about £20, but you should also ask your friends/family if they have one you can borrow when you get started – they’re used for stripping wallpaper and paint.
If a piece of armour is going to be curved into shape, you will typically need to make the pattern a bit bigger, as the thickness of the foam reduces the circumference of the foam as it bends. The thicker the foam, the more extra length/circumference you will need, and the harder it is to bend, so choose your thickness carefully. I’m using 7mm.
To heat the foam, make sure there are no fire hazards near by (e.g. curtains, carpets, upholstery) and then turn on your heat gun to allow it to heat up. Once the heat gun is hot, heat both sides of the foam until the foam is pliable. The time this takes varies depending on the thickness of the foam and the strength of the heat gun but usually won’t take more than a few minutes. If it’s your first time using the heat gun, test on some scraps first. If the foam discolours or bubbles, you’ve overheated it.
For this breast form, I’m heating the piece of foam repeatedly and punching it into the bowl with my hand (I’m wearing a glove because it needs to be quite hot). I then hold it until it cools.
You can mold around the outside of a form too, or you can simply bend the foam into shape with your hands. Foam is quite safe to mold on a mannequin or yourself as long as it’s over fabric, just use gloves if you need to heat it repeatedly. Hold the foam in shape until it is cooled, and the foam should keep the shape!
For more complex curves, you can separate the form into several pieces and bend them separately, then glue them back together again. This technique is great for helmets but you will need to sand down the joins afterwards to make a smooth curve. This is a technique that works well with pepakura templates.
HELP! My foam isn’t bending/keeping it’s shape!
Solution #1 – your foam isn’t hot enough. Try heating it again. When foam is hot you can usually press it with your finger and the indent will stay there.
Solution #2 – You’re letting go of the pieces before they have cooled. Foam will spring back into shape as it cools unless it’s held in place.
Solution #3 – with thick foam, try over bending the piece – so if you want two edges to meet, bend them past each other. Foam naturally springs back a little from the held position, so if you over bend it it should spring back into the correct shape.
Solution #4 – for more extreme curves, you will usually need to heat the foam, bend it, heat it again, bend it a bit more, etc… until it’s in the shape you want.
To finish your basic foam piece, you will usually need to glue pieces together. With any edge or surface, make sure it is sanded smooth and dust free. If you are joining two pieces together on a curve, you will need to sand the edge down to conform to that curve.
You can use a number of different glues on foam.
Hot Glue – a lot of people love hot glue. Hot glue bonds as it cools and can stick unevenly cut surfaces together. Personally I don’t use hot glue because if you heat the piece, it will fall apart, and it’s not the strongest bond in the world and I like to know pieces of my armour aren’t randomly going to fall off. It’s also very messy (and hot, ow). But it’s great for a bond that you aren’t going to put under pressure and it’s also cheap. Additionally it’s easy to peel pieces off and re-stick them if you do something wrong. You can get glue guns in home/hardware/art stores.
PVA Glue – PVA is very cheap and can be used for sticking layered surfaces together (such as details). PVA however takes a LONG time to dry on foam so you will typically need to leave it overnight. Get it from arts and crafts stores or supermarkets.
All Purpose Glu & Fix – moderate strength glue which is good for non-pressure joins. It can be used as a regular glue or a contact glue, where it is applied to two surfaces then they are brought together for an instant bond. Glu & Fix joins can often be pulled apart if they’re glued wrongly, but may damage the foam. You can get this stuff from hobby/art stores and supermarkets, and it doesn’t stink so it’s safe to use in the house.
IMPACT Instant Contact Adhesive (US Alternative – BARGE) – to say I love this stuff would be an understatement. This is a very high strength contact glue. You can use it to glue pretty much anything to anything and I use it for high-pressure bonds such as straps (and most others things… because it’s awesome). It is however very expensive, and has a very strong smell, so should be used in a well-ventilated area.You can also get a re positionable kind which allows for adjustment as the glue dries. Get it online or from home stores like B&Q and Homebase.
HOW TO USE CONTACT GLUE
Contact glue is very strong, but it can only be used on joins where the two surfaces will meet evenly, so make sure you sand down your edges first. It creates an instant bond so can be used for those awkward joins – no need to wait for it to cure or clamp it.
Once you have two smooth surfaces that will meet evenly, apply a thin layer of glue to each. Wait 3-10 minutes for it to become touch dry or tacky. (Check the instructions on the back of your glue container). Bring the two surfaces together and you should get an instant bond. Leave it for 24 hours to fully cure and you pretty much can’t pull it off (you will rip the foam rather than the glue).
Here’s a gun that I glued together. I used thin foam to create the detail panels – you could use PVA glue to glue them on if you’re patient enough to let it dry (I’m not). You can see that I still need to do more work on sanding down the edges!
So with all of these techniques you can make your basic foam armour set, and if you want, that’s where you can leave it. But if you want a truly polished set, you’re only 50% done – the next article will cover priming, painting, polishing and weathering! If you have any questions, problems or just want to get in touch, drop me a line at Nat Martin – Artist and Cosplayer.