Iron Man Foam build ... sanding advice??

So I decided, thanks mostly to xrobots and stealth, to try my hand at making an Iron Man suit out of foam and casting it in plastic. Last year I built a Master Chief suit in Pepakura and though it looked decent it had some flaws. I hope to do better with this suit. I am currently beginning the casting process and I wanted to know if anyone had any sanding tips? I know it will come down to a lot of time and elbow grease but any pointers would be greatly appreciated!


(attached is a picture of the suit in foam and the helmet during the PVA coating process)

sanding the pva glue on the foam? i use steal wool i found sand paper was too much

I should have been more specific in my post lol sorry. I meant sanding the polyerethane once I cast it. I haven't made the casts yet but when I do I am going to have a lot of details to touch up and wanted to know what the best methods were? Do people use sandpaper by hand, an electronic sanding pad, a dremel etc. How do you make sure the corners are crisp?