Hey all! So a local jewelry store has asked me if I could make a wedding cake for them for their display window. Obviously this can't be a real cake because everything would melt and go bad and just get generally icky. I know i've seen completely fake cakes here before with styrofoam and i think it was plaster for icing. Anyone have any tips on making one of these? TIA!

You can purchase styrofoam cake dummies at:
http://www.countrykitchensa.com
http://www.dallas-foam.com/store/cakedummies.html

You can ice them in royal icing and fondant or you can use perma-ice (which is a non-edible icing-like substance made just for dummy cakes and must be colored with special coloring).
You can purchase the perma-ice and the perma-ice coloring at:
http://www.countrykitchensa.com

I just use royal icing and fondant on my dummies - it will last for years using these just fine.

Remember to make the edges around your dummies smooth so the fondant will not break. Also if there are any gaps, scraps, etc. on your dummy, fill them in with royal icing, let dry, sand down and then cover in fondant.

Just spritz the styro dummy with water to make the fondant stick to it.

I just ice my styrofoams in plain 'ole BC. It hardens like concrete and works fine..... no "melting".