How I cast one of these suckers

Well, since I wanted something sturdy, cheap, and hollow I decided to go with polyester resin and fiberglass mat.  I started out by mixing up some resin with some talc and pigment, a nice thick consistency like cold honey.  I brushed this into the mold trying to get an even thickness on all faces while keeping the lip of the mold free from resin.  This was allowed to gel and was backed with two layers of fiberglass mat.  At this point the mold was closed, with some mat left "dry" sticking from one half of the mold into the other to bond the two halves together when a resin/bondoglass mixture was poured into the casting.  This mixture was slushed around onto all areas of the seam until it set.  Another coat of this was slushed in trying to get it onto the entire inside surface.

At this point the mold was allowed to set for maybe an hour, then opened.  The casting was carefully removed from the mold.  Some sections didn't have full coverage, so further mat application was done, as well as bondo on the outside of the casting.  This was all allowed to set fully, then sanded and blended into the contours of the battery.  The bottom required further attention to seal the pour hole.  Fiberglass tape was used to cover it, then bondo was smoothed onto the bottom in two thin passes completely sealing the hole and leveling the bottom out nicely.

Further sanding, spot putty application and finishing was done followed by a coat of primer.  Paint was a mix of several acrylic colors airbrushed on, then several coats of clear acrylic spray finished the paint as well as the entire green lantern power battery.  

Just a note, I may work on the illuminated version and add some detail on that in the future, but no time for that right now, sorry.

Proceed to the casting gallery