Expanding foam?

**Guest** Guest

So whats the dealio with expanding foam? Who has used it before. It comes in a can, right? How much foam would you get out of a can, how does it work, how heavy is it, how easy is it to work with and how much is it? I'm going to be working on two 'props' for next year that are going to be quite big (for a character who my friend really likes and I'd like to give it a go for him, and it looks mega awesome) and I will have to have them light enough to be on my arms and still move.

Spoiler:

^Essentially it's the same as the the giant arm thingies, it's for:

Spoiler:

Not sure whether to use cardboard or Expanding foam. I guess cardboard would be easier but I've been told expanding foam is really good. So yeah, I kinda wanna know what I'm getting myself into ^^'' Thanks in advance guys c;!

**Guest** Guest

I've been using it a lot lately.
It's kinda steep - about $20 for a can.
You squirt it out, (you can empty a full can in about 3 minutes squirting) and then the stuff expands and sets. About 20 minutes until it's not sticky on the surface, and then another hour or so until it's solid.
Then you carve it back into shape. It's really smooth the cut and a standard craft knife goes right through.
It's got a quite variable texture - the second squirt is usually smoother than the first because the pipe is clogged. Lots of air bubbles you'll need to refill if you carve into them.
Very light - a to-scale version of that arm would be a couple of KG's at most.
Have not yet painted, but Luke has, and it needs lots of coats to mak it smooth.

**Guest** Guest

Hmm okay, maybe just using cardboard would be best for this project..

By RainbowMoonDust. 11/05/11, 09:59 am

Hijacking this thread for a moment because I want to make the image in the picture below sometime far in the future, looking at next year maybe.

Spoiler:

See that armour he's wearing? That is what I'm thinking of using the expanding craft foam for as it's one of the few things that I think might work. :think:

So basically I want know where I can buy this stuff from and how many cans would I probably need? Any info and much of it as possible would be helpful as that armour is going to be a beautiful and wonderful person to make. Smile

By **jpwise**. 11/05/11, 12:04 pm

Just for both of you - don't forget you can use craft foam aswell. If you build it over a frame of some kind, stick the craft foam to it, seal, and paint, it should be fine.

Casey - on yours you could probably build most of the frame using cardboard and then just finish with craft foam over the top for finish and texture. Perhaps something a bit stronger in the middle to hold onto since the cardboard may bend.

RMD - I'd go with a wire or light plastic piping frame - moreso for the bit that goes up and around his head. Wire you may just be able to push through the foam, or otherwise glue two pieces either side of the whatever wire/pipe you use.

PS: I'm totally not advocating the versatility of EVA/Craft Foam after having looked at the thicker stuff you can buy from foam distributors in 2meter sizes instead of the tiny A4 ones. Totally Not. Razz

PS2: Erm yeah - slightly off topic here, but hopefully still helpful in terms of construction ideas.

By RainbowMoonDust. 11/05/11, 12:17 pm

Quote :: Just for both of you - don't forget you can use craft foam as well. If you build it over a frame of some kind, stick the craft foam to it, seal, and paint, it should be fine.

Quote :: RMD - I'd go with a wire or light plastic piping frame - moreso for the bit that goes up and around his head. Wire you may just be able to push through the foam, or otherwise glue two pieces either side of the whatever wire/pipe you use.

I was going to construct a frame out of some sort of light wire or plastic piping, I'm well aware that I need to build a frame for it or it won't hold up, lol. Do you know what type of wire (Ie: Name) and where I could find it? I'm guessing a hardware store. Craft foam? I didn't think of that, ruled it out because I thought it would be too soft. (If that makes any sense). :think:

The other option I was thinking of was Paper Mache or paper Magic Clay or something similar but am worried that might be too heavy. :think:

I'm going to experiment with different materials and see what works, I'll try Craft Foam as I need this to be as light as possible, thank you. Smile

Quote :: PS: I'm totally not advocating the versatility of EVA/Craft Foam after having looked at the thicker stuff you can buy from foam distributors in 2meter sizes instead of the tiny A4 ones. Totally Not.

If you can point me in the direction of such distributors then that would be helpful and I'd be grateful, thank you. Smile

By **jpwise**. 11/05/11, 12:38 pm

Any mid-weight wire should be fine. Just avoid high tensile stuff since it tends to be REALLY hard and springy, you want softer stuff you can shape. Old school #8 wire style.

Another thought is depending on how much strength you need to support it would be look at irrigation bits - they quite often have plastic mid-weight pipe, angle bends, and all sorts, all in sub 10mm thickness. Thats just an idea tho - you'd have to go see if what they've gots actually suitable or not.

Para rubber does the sheets, but since they're not in Wellington, I found the other ones online - just search eva foam distributor wellington and half the matches were on Yellowpages. Razz

By RainbowMoonDust. 11/05/11, 12:43 pm

Alright thanks JP, that info about different wire types is useful, I'll keep it in mind when I finally get around to sourcing materials for this sucker. Smile

**Guest** Guest

The Expanding foam I've been using is sturdy, and with a bit of lateral thinking, would go into the big swooping shapes of that armour. I'm not sure if it would be too brittle or not.

By RainbowMoonDust. 12/05/11, 08:11 am

Quote :: The Expanding foam I've been using is sturdy, and with a bit of lateral thinking, would go into the big swooping shapes of that armour. I'm not sure if it would be too brittle or not.

I have been wondering if it would be too brittle or not. :think:

I'll try it out at some point, thanks. Smile

By Mischa. 12/05/11, 11:17 am

How to do it Very Happy

https://www.youtube.com/watch?v=O23TM-z0OXk

Expanding foam seems to be really good for organic shapes

I would use cardboard for the arms- since they are all boxy shapes. I feel it would be difficult to get the sharp corners + joins with craftfoam :/

By RainbowMoonDust. 12/05/11, 11:49 am

Thanks Mischa, I'll check that out too. Smile

Down below is a link for a Expanding Foam tutorial if anyone else needs it. nodnod

http://kamuicosplay.blogspot.com/2010/10/about-my-love-to-expanding-foam.html

By Rikki-Leigh. 12/05/11, 12:36 pm

... I think I might use this stuff for Braig's crossbows. A lot lighter!

Question as well. I'm making A-Ts for Spitfire (sorta based off this tutorial https://www.youtube.com/watch?v=Pv9jVO4YlqU&feature=related). Do you think I'd be able to use expanding foam in place of the clay?

By azeria. 12/05/11, 02:33 pm

RainbowMoonDust wrote:: Craft foam? I didn't think of that, ruled it out because I thought it would be too soft. (If that makes any sense).

As long as you add some sort of backing (Fabric + glue or whatever) then you can get it quite stiff. I used craft foam for all of Meiko's armour.

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