Seeking Advice on Building Foam Cores...

[GeekNeko]

Hi RPF,

So I'm about to start gathering materials for my first replica (the radio from Portal... yes- another Portal nerd here), and upon looking at a few others that have built this, it seems like the best way to get the form I'm after is to build up a foam core and cut/sand it down to shape.
The specific blog I looked at mentioned using a 1" thick foam sheet to cut from, but for the life of me I can't determine what kind of foam he used or where to find it!

I get the feeling it's been right under my nose the whole time, too :rolleyes

As far as that goes, is building it up and laminating it a better idea than carving out a foam block? Or is that just a matter of preference?

Any advice will be greatly appreciated!

 

[klamathpro]

As I understand and from what I've seen, the green foam used for flowers is a good start. You them build it up with bondo and then sand some more. You can get these 1" thick green or white foam from your local or online Hobby Lobby.

 

[Leigh]

I dont know if its any help but I used a foam core for my Alien project.
The first page has some info on the foam I used & how I used it:

http://www.therpf.com/f9/bob-alien-giger-inspired-alien-121902/

It was my first time using a foam core but I think its worked out ok for my needs.
HTH

 

[sycor]

As I understand and from what I've seen, the green foam used for flowers is a good start. You them build it up with bondo and then sand some more. You can get these 1" thick green or white foam from your local or online Hobby Lobby.

I've heard the opposite. The the green flower foam is too soft and brittle. Most people seem the use the kind of foan you find in sheets at Home Depot or Lowes. They are usually blue or pink. You glue a few sheets together to get the desired thickness and then remove everything that doesn't look like the item you are trying to make.

 

[GeekNeko]

Thank you for your replies, all. My project has been on the back burner for the last couple months - between getting married and all the holiday bustle, there just wasn't a whole lot of down time. I ended up going with Styrofoam... never again. The stuff just falls apart and makes a huge pile of Styro-snow on your work surface (and pants)...

@sycor, the sheets of foam you're talking about are those giant sheets, right? I was considering that, too. I think I'll be using that for my next prop (if I ever finish this one )

Thanks again

 

[clonesix]

my personal preference is 4# polyurethane foam (insulation material)

FR-7100 Last-A-Foam | General Plastics Manufacturing Company

Carving / Sculpting Foam

S7114




Also, don't use Bondo plastic filler. It is too much work to sand. Instead, use glazing puty. It is lacquer with filler. It can only be applied in thin layers, and takes a while to air dry, but it sands very easily.

 

[NormanF]

I use FloraCraft Desert Foam. It is not the very soft foam that will dent if you just look at it, but you do still need do be a little delicate with it. You will definitely want to put a layer or two of resin over it before you use body filler. The guy doing the Green Lantern lantern is using the same thing or something similar.

 

[GeekNeko]

Thanks clonesix, those links were very helpful. The taxidermy one threw me off for a second, but after I clicked on it... everything made sense

Norman, I thought about using the desert foam, I'll probably go with that for smaller scale projects. Thank you!

 

[clonesix]

all my stuff starts off as a foam block, as if shapes quickly, and if you make a mistake, just cat it out and glue in a new piece to start over.

 

[GeekNeko]

Hmmm... I might just start over at this point- I think I've made it much harder on myself than it needs to be