View Single Post
Unread 11-26-2012, 01:45 PM   #1
JoyMason
Now Joy Sutton!
 
JoyMason's Avatar
 
Join Date: Apr 2007
Posts: 340
EVA Foam and Stretch Vinyl for Armor - Ligthweight, Flexible and Shiny! [Pic Heavy]

Just posted a new tutorial on my blog, Joy Sutton Props, and I wanted to share it here as well.

Today I want to show off a little technique I've been using for one of my commissions. The client has asked me to create a set of Megaman Starforce armor that is lightweight and flexible. I racked my brain a great deal on this, and had a lot of trial and error in developing this technique, but I feel I now have it to the point I can share the method.

Lots of folks in the costuming community make use of EVA foam (foamies, craft foam, yoga mats, ect. Proper name Ethylene-Vinyl Acetate foam) to make armor, props, jewelry and all sorts of bits for their costumes. I've seen everything from angel wings to N7 armor to LOTR armor made from the stuff. It's economical, easy to cut, heat formable and very lightweight. However, I've found that it's a real pain to paint, and the finish will never really be smooth enough to pass for high gloss plastic or metal (though careful weathering can help trick the eye in the case of metal).

The solution? Build the structures you need in EVA foam, and cover the foam in stretch pvc fabric!
Vinyl fabric is very durable, resists just about anything you throw at it (only second to wig fiber in chemical resistance in the costuming world) and comes in a decent variety of colors nowadays. I get mine from primarily spandex vendors, so the fabric itself is 2 or 4 way stretch spandex with a thin, flexible layer of pvc. There are even passable gold and silver pvc spandex fabrics available; I have used both, silver in Ed's Automail, and Gold for a few recent comic commissions, work fine for non-weathered metallics. I personally get my fabrics from Spandex World (free swatches!) but friends also swear by Spandex House. I should also note that this method will work with any stretch fabric coating on the foam, so don't be afraid to try it with other types of spandex and knits.

So, without further ado, on to how this is done.

You'll Need:
  • Foam! I prefer to use 3mm thickness craft foam in complimentary colors to the finished piece, but under an opaque covering it doesn't matter what color foam you use.
  • Stretch Fabric. Stretch PVC, spandex, ect.
  • Contact Cement. I use Super Glue Brand Contact cement, it comes in a yellow and purple tube, but any contact cement that lists vinyl or rubber as an acceptable surface will work.
  • Cotton Swabs, lots of cotton swabs.
  • Fabric scissors.
  • Hobby blade or scissors for the EVA foam. I prefer using a hobby blade as it doesn't crush the cut edge like scissors, which gives a better bonding edge to work with.

First, you'll need to cut your EVA foam into the shapes you'll need. In this tutorial, I am constructing the backpack for my client's Megaman costume. Once you have your foam pieces cut out, take the time to make sure they fit properly, as this is the last time you'll want to cut the base forms at all. They need to be exactly what you need before applying the fabric. Once you have your foam pieces, lay them out onto the back side of your fabric, with the foam piece's back side facing you. Now, cut out your fabric with some extra to work with on the outside. I usually leave anywhere from 1/4 to 1/2 an inch extra when I work with 3mm foam, for thicker foam, leave more fabric.


Next, cover your workspace with something you don't care too much about. If you are working on a wooden table with varnish, cover it up! The contact cement's fumes will melt varnish (trust me, I now have a bit on our dining table to resurface). Now, you'll want a bit of scrap card or paper to put under your tube of contact cement (this stuff is messy coming out) and your cotton swabs to apply it with.I also recommend keeping a very clean workspace here, this stuff has the potential to get messy.


Now, keeping your EVA foam from moving around on the fabric, start applying the contact cement, via cotton swab, to the cut edge of the EVA foam and on the fabric next to it. With a little practice, you can do the two at the same time. You'll want to make sure the cement doesn't get under the EVA foam and onto what will be the "face" of the piece, as the cement can make the vinyl warp and you'll end up with ripples and wrinkles. I usually use one hand to hold the foam in place and one to apply the cement.

Now, the piece needs to have 3-5 minutes to set up. Contact cement will stick if you just put the two surfaces together immediately, but not very well. You leave the cement exposed to air until it becomes just tacky, then you can press the surfaces together and get a very tough bond. If you have a tight curve or sharp angle, now is the time to cut some slits in the fabric to allow proper give. I find you really only need them on inner curves and angles, but here are a few for demonstration purposes. Cut to within a hair of the foam edge.


Now, once notches are in where necessary, and the cement is tacky, you can fold the edge of the fabric up to touch the cut edge of the foam. The bond will be instant, so be careful as you go. I find the best way to do this is hold the foam down with one hand, and slide your finger underneath the fabric edge, pressing against the foam through the fabric. Try to not stretch the fabric as you do this as well, or the final piece may end up with wrinkles.


Continued in next post!
__________________

Tutorials, showcases and materials reviews!
JoyMason is offline   Reply With Quote