Amanda’s Monthly Cosplay Tip: Choosing Adhesives

Nothing is worse than having your hard work fall apart on you, especially right in the middle of the convention!  Choosing the right way to attach your creation together, right from the start, is crucial to make sure accidents don’t happen.

First off, decide whether or not you should be physically connecting the two pieces in question together.  Consider if you should be sewing or otherwise using a physical binder (like nails, screws, staples, etc) to keep your pieces together, or if an adhesive is would be appropriate.  If you are connecting two pieces of fabric, sewing is going to always be a better option as you have more stress you can put on the joining area, but two pieces of plastic should be connected using adhesives. Adhesives are also preferable, if you are connecting two things that aren’t made of the same material, like plastic onto fabric.

Secondly, make sure you select the correct adhesive for the job.  A polyurethane glue may be amazing at connecting two hard, non porous materials, it won’t work so good with foams or fabrics.  Make sure you read the labels of the adhesives, so you can make sure it’s the right stuff for the job at hand. There are many many different adhesives out there, so I’m sure you will find something that fits what you need it for perfectly.

Third, read the instructions!!!  Some glues are toxic, some require additional time and conditions such as heat to fully bind together, and others may damage the materials you are working with and require a test usage first. You wouldn’t want a small avoidable mistake to ruin dozens of hours of work just because you didn’t read the instructions first.  This is where the scraps and bits left over from crafting your costume and prop pieces, can come in handy. Grab a small piece of what you are adhering and try it out first before putting it on the final cosplay. Some adhesives work really well ONLY if you follow the instructions very carefully (such as contact cement), so as tempting as it is to jump right in, glue in hand, testers are really important.

Finally, if the worst does happen and your costume or prop does come apart at Otafest, make sure to come by the Cosplay Repair Station.  We make sure that we have all sorts of adhesives and other materials on hand for you to use to help save your cosplay!

Cosplay 101: The Art of EVA Foam

By: Kendra K.

Hello everyone, I am here to talk about a now-common material that many cosplayers use: EVA Foam!

EVA foam is a light-weight, durable, and cheap foam material, which can serve as a great alternative to other materials, such as Worbla (a thermoplastic used often for props and armor). Foam can be used for armor pieces, props, and more: the possibilities are as endless as your creativity! If you make sure to work carefully during the building process and cast a careful eye to painting, you can achieve really clean finishes, mimicking the look of metal or other interesting textures. EVA foam comes in a variety of sizes and styles, so make sure you do a bit of research before you dive in!

There are three main different types of EVA Foam:

  • High Density
  • Floor Mats (diamond or cross pattern)
  • Craft foam

A variety of thicknesses in high-density foam.

For the following build, I am using a high-density foam which comes in a variety of thicknesses. Floor mat style foam and craft foam, generally are available in limited sizes, but can serve their own purposes. Just keep in mind that floor mat foam is thicker and sturdy, while craft foam is thin and great for detailing.

I find the best way to tackle a new project is by drafting up patterns. Paper patterns can help you come up with a shape, and when you cut it and lay it flat, you will find that foam is flexible to creative a huge variety of different shapes to suit your needs.

An example of my paper patterns.

I just mocked up two patterns where you can see the use of darts and odd shapes. Another advantage of  using patterns is that it allows you to map out where you want to cut in order to save material for future use.

Tracing the pattern in an optimized fashion.

The easiest way to go about cutting the foam is using a sharp X-Acto blade. The foam is relatively easy to cut through by hand, but the blade can dull quickly. Regularly switching to a new blade may be needed to make your life easily and ensure your foam has a clean cut.

Use an X-Acto knife! Make sure it’s a new blade!

Alternatively, if you have access to power tools,  you will find foam is very quick and easy to slice through. I personally use a band-saw when I need multiple pieces to be identical, as I pin several layers together. Just remember to get supervision if you are new to power tools!

Pinning together layers of foam for cutting identical shapes.

See below for the different results of different tools and blades:

The edge on the left is an example of using a dull blade, creating a “sawing” motion.

The results of the bandsaw.

For further shaping, you can cut the edges on an angle in order for pieces to lay fatter against each surface. This can also help you achieve a desired shape and appearance.

Shaping the edges of the foam.

For the next step: glue. While many cosplayers would consider the hot-glue gun to be the best friend of the craft (and it is), you’ll get the best results with EVA foam by using contact cement. Contact cement helps create a permanent bond that is still flexible and is relatively fast drying. You can pick this glue up at most hardware stores.

Something like this would work great. Notice the applicator!

When working with contact cement, you will need to make sure you are protecting yourself properly. Make sure you are using a quality respirator and working in a space with good air flow, as the fumes from contact cement are toxic.

I’d recommend a respirator like this!

To apply the glue, you will want to brush on a thin & even layer that covers the surfaces you wish to attach and wait 5-10 minutes for it to dry (read the instructions on your bottle of contact cement!). When the surface is no longer tacky, that is the ideal time to press the glued edges together. If you don’t wait long enough, the glue will still tacky and that can prevent the edges from sticking.

Make sure you use a thin even layer on ALL edges, as contact cement needs to adhere to contact cement.

Keep in mind that contact cement is not forgiving, so there is little room for error once both surfaces have dried sufficiently and are touching. You will need to be extra careful at this step.

I’ve attached all 3 pieces together carefully.

To finish off, the last important tip I can give, is to remind you to carve the foam to smooth out your desired shape. This can take some practice to get the hang of it, so feel free to practice on scrap pieces. The simplest way to carve your piece is going back to your trusty X-Acto blade and cut the foam in small pieces, building towards the end result.

You can really clean up your shape!

The foam can be sanded as well, which will reduce any bumps or rough areas that need to be fixed. You can sand by hand or by using a dremel (I highly recommend a dremel, as it saves a lot of time, protects you from pesky hand cramps and gives a great result).

Sanded and smooth!

Once you have your desired look, you will finish off this part of the project by heat sealing the foam. To do so, you will need a heat gun or another high temperature source. This closes the cells in the foam that you may have created through the cutting and sanding process. Heat-sealing foam is important as it adds the final step of smoothing the surface, which is key if you continue to seal and paint the foam.

Notice how it becomes shinier?

Many cosplayers prefer this material over other types, as it is lightweight and relatively inexpensive, but each technique has their own advantages. I hope you feel you better understand EVA foam and feel equip with a few techniques to help you get started, armed with this bit of insight on EVA foam.

Good Luck and Happy Cosplaying!

An example of a prop dagger I made from EVA foam.