VERY interesting question. First of all it depends upon what kind of foam you're talking about.  In MANY cases, molds are made in silicone from SCULPTED props and then a urethane foam is used - which is a two component mix of foam base with catalyst.  These are SELF-RISING foams which expand (some create their own surface skin) and are available in a variety of DENSITIES. Many - if not most - are EXTREMELY CARCINOGENIC and must be used only with proper ventilation and respirators - BEST used outdoors, upwind, mix, pour and run like hell and let the foam expand on its own releasing the gases to be mixed into the air and dissipated in that fashion.  And again something the size of a fridge or a stove is likely NOT made from a sculpted item with silicone molds - but rather either molded with the white beaded type styrofoam or CARVED out of large blocks of styrofoam or stacked and glued styrofoam slabs.  We used to have an old potbelly stove made from styrofoam that was given to us from an old liquor company who used it for displays and such and we lucked into it. Pick it up with one hand.  Over the years it did get beat up pretty much and repaired MANY times.  We even tried a light inside to illuminate as if a fire were burning inside but got too hot.  NOW with LED lights it could be accomplished safely and get the effect.

 

BUT to your question, it would be a matter of having someone skilled enough to be able to either carve down a huge piece of styrofoam (and yes you CAN get huge blocks from the companies who make, distribute or sell it) and then with either an electric knife OR better yet, a common HEATED WIRE TOOL, you can carve it to whatever size and shape required.  Gives off some stinky fumes, COULD BE toxic with constant inhalation but with proper ventilation not a major issue to tool the shape with a heated wire tool made for this purpose.  You could build a simple light weight luan form(s) and frame, then layer white styrofoam on top of this simple framework.  You can get large sheets of styrofoam several inches thick from the manufacturers, distributors or styrofoam - though the white beaded stuff makes a huge mess when carving it.  You could use the 1" or 2" insulation foam (blue or pink), stack slabs of that glued together (again SPECIFIC glues otherwise it can MELT away with glues using certain solvents as their base) and then when you have enough pieces stacked, carve that back down, paint white and there you are.

 

Intersting idea - though there MAY already BE some company who specializes in "styrofoam props" out there though usually when you find a piece made from that stuff, it's likely to be expensive.  BUT MAN would that be useful to store, to move around, etc.  However it CAN be damaged, punctured, broken, cracked, melted, dented, etc., etc. VERY easily so using it and maintaining it would be paramount if it were to be saved and reused many times.  Got to respect that it's VERY fragile and maybe too much so for SOME prop uses - especially in large appliances and especially if those appliances were to be used at all rather than just BE there for set dressing and such.

 

Good luck - sounds like a good idea and fun to create this stuff.  Seen it done and it CAN work well - just have to be careful of the stuff.  SMALL props can still be sculpted, molded in silicone and have urethane self-rising, self-skinning foam pieces created at a fairly reasonable cost.  Components however have shelf life but can be purchased in a variety of quantities so using it up is best in reasonably short time (6 months or less) is a good idea and buying ONLY what you think you need for making what you have in mind to make.

 

Have fun.

 

 

TonyDi

 

I have made a car with it and a coke machine

I could email pics  but i would need an address?

To glue it together I used a chak Power Grab

you can carve it with a saws all  (wood blade)  and make  it smooth with a

belt sander w/ different couse to fine papers