Crafting weapons with foam

New member - first post! I am creating prop weapons and armor using the recommended foam mat / barge process. I have read many of the pdfs available on the topic and watched scores of videos - particularly from Punished Props. When gluing together two halves of a sword, I was met with some surprises. Everything I had seen suggested Barge went on clean like superglue. It was very thick and gloppy - like mucilage. I tried to coat the two halves, wait for them to set up then press them together. It was a sticky ineffective mess. Another issue is that i tried to glue the textured side on the inside so contact was less than good. So - question - must i use the spooth side to clue and is there something I can do to get the effective coat on each side, wait and press that I hoped for? Also - will the bond between the two mated halves be consistent enough to serve as the edge of the weapon?

thanks for whatever guidance you can offer

Hi,
while I find EVA foam to be too flimsy and bendy for my purposes, I nevertheless did some experimentation.
I don't have the same brand, but I'm using contact cement a lot, the quality that shoemakers and leatherworkers around here use, I got it from them.

Concerning your first issue, that sounds like either your barge cement went bad (stored somewhere the sun sines on it directly?), or you didn't wait long enough for it to dry. With EVA foam, I like to do 2 thin layers - the first one gets sucked into the foam a bit, and the 2nd stays more on the surface. However, what is also possible is that it did not get sucked into the foam at all, related to the 2nd issue.

I found gluing the textured sides together a horrible experience. I think that the way they add the texture entirely seals the surface and makes it too smooth for the cement to stick to. Whenever I tried it and did some stability testing, It simply went off of one side. So, if I really need to glue 2 layers of EVA together, I first try to sand away the texture as much as possible, although that's a horrible, horrible process. The dust you create (and you create lots of it) is, afaik, pretty toxic and sticks everywhere. Also, you need either a belt sander or a rotary tool, preferably with a large sanding surface area. Hand sanding won't get you far due to the flexibility of the foam.

Tl;DR: If I ever do an EVA project again, I'll get untextured foam.

Thanks. I'm going to try to sand the joins smooth and two think coats.

As far as Barge goes, it tends to be pretty thick. It does tend to get pretty snot-like, especially then it gets old, but it should still work! Spread it on fairly thin; enough to completely cover the two surfaces, but not to leave big puddles of the stuff. Then let it dry! It should be dry to the touch. Feel free to use a hair dryer to speed it up. (I do!) Then press the two surfaces firmly together, and they should grab instantly. If you leave the stuff to dry too long (maybe a few hours) it might not work, but simply apply another thin coat to reactivate it.

As far as the surfaces go, the texture should matter too much. With a good barge seam, the foam will tear around it long before the barge lets go.

Depending on your intended use of the prop you have a few different options. The previous posts here have said it pretty well, sanding the texture down can help a lot and even just roughing it up may help you out. With Barge like all contact cement a little goes a long way. If you have too much on the surface it can lose some effectiveness.

Now if you are simply making this as a display item and it won't be smashed about everyday may I suggest laminating the two halves together using good quality hot glue. Not a fancy solution but for big jobs like that it is very effective and simple. No respirator needed and the hot glue takes hold of the EVA quite well.
As for the edges if there are any undesirable gaps between layers at the end before you seal the foam in preparation for paint get yourself a tube of DAP Quick Seal. It dries flexible and will seal and paint beautifully.

Hope that helps out.

I only used the textured EVA once. I switched to different material - cross-linked polyethylene, available from foambymail - which is very similar. In addition to being available is a variety of thicknesses and coming smooth on both sides, it can also be cut with a hot wire tool unlike EVA (in my experience).

EDIT: For weapons I also like to do a core of MDF. It makes it heavier, but less flimsy and bendy.