How to make a Sphere out of sheet foam? for a puppet head?

Question

All I can find to buy to make my puppet is sheet foam (from wal mart). I couldn't find a block of solid foam from lowes, or hobby lobby or anywhere... not even an online store (does anyone know where to find a big solid block of foam online?)

Anyway, is there a pattern that anybody knows of that I could follow to make a large sphere out of my sheet foam? I tried to cut "wedges" but it's so difficult with nothing to go by...

Answer 1

First, if you want to make a sphere from any shape of polystyrene foam, the best way is to buy one that's too big, then "sand" it down.  You can use various tools to do that, from rasps and sandpapers, to the cut edge of another piece of foam.  (You can start by cutting larger parts off first if you want with a serrated knife, or hot wire tool, etc.)

Secondly, there are two main types of ps foam.



One is "expanded"--that's the kind that you usually see at craft stores and as shaped blocks of packing around computers, etc.  You can probably also buy it in various shapes from packaging stores.   It's made from loads of tiny styrene balls pressed together till they make a solid shape.  Pieces made from that type of ps foam will be crumbly when you try to cut or sand them, but they're possible to use.

The other type is "extruded" ps foam --you'll find that kind at home improvement and hardware stores, usually in several places... they're used for various kinds of insulation.  That kinds of ps foam is much denser, so it's not crumbly when cut or sanded so it can be easier to handle and shape, and more detail can be achieved too.

Since it comes in sheets, to make a shape that's larger than the sheet is thick (like a sphere), you'll want to stack several pieces of the ps foam and glue them together; when dry, the new shape can be cut and shaped in the same ways as the expanded stuff.

You can find more info on doing that on this page of my site, if you're interested:

http://glassattic.com/polymer/covering.h...

(...under the Plastics category, click on the subcategory called "Shaping, Cutting, Gluing PS Foams"...)

EDITED TO ADD:

After rereading your question and the answers, I'm thinking you may be wanting the type of foam sometimes referred to as "foam rubber."  If that's the case, everything I said above wouldn't work.  

That type of foam can be purchased at fabric stores in various sheet thicknesses and sometimes as shapes.  I've also seen it in "foam stores" which sell foam and upholstery fabric for covering it.  You could try looking in your yellow pages for one like that perhaps.

Since that type will be really hard to cut into a satisfactory sphere, you might want to go instead with buying a "Nerf" ball of the appropriate size (that may be a brand name, but there should be others at toy stores and perhaps at sports stores).  

HTH,

Diane B.

Answer 2

I don't know where to get block foam online, but they sell it in upholstery supply shops. It's so expensive, you wouldn't want to buy it. To make a sphere out of sheet foam, use a ball pattern. Here's one:

http://www.thesilverpenny.com/FeltBall.h...

.

Answer 3

You should check out the puppet patterns at Project Puppet.com. They use sheet foam, and include it in the pattern they send you. You can also buy more via their supplier if you need it. Solid foam blocks can usually be found at hardware stores, but I'm not familiar with your area so I can't recommend any place specific. If you want to learn more about making foam puppets, I recommend checking out Puppets and Stuff.com, there are heaps of useful things there, including a tutorial on using a 'wedge' method to make foam heads. (Do a search for 'wedge' and 'Andrew'... Andrew from Puppetvision.blogspot.com wrote the tute.)

Additionally, I highly recommend investing in The Foam Book, which shows you how to make foam puppets - there's also a DVD which is great.

http://www.amazon.com/gp/redirect.html%3...

Using that felt ball pattern won't exactly work, because you'll still have to accommodate the mouth, and access to the mouth.