Woah, woah, woah, one word: brass. Flattened brass pipes. oh yeah.
Anyways, I think that a flattened brass/copper pipe would make an amazingly strong core.
A rule of thumb is to NEVER use a metal core. They can be much too heavy and have no 'bend' to them. While my Katana 3.0 also has no bend, it would go back to its original straightness if it did bend in any way.
As for using hollow metal cores, if you flattened brass pipe (which is already a pretty weak core and expensive and only readily available in 1 foot lengths), it would make it stronger in only one direction, and if anyone were to parry your sword, it would be bent crooked, eventually being bent and unbent to the point of metal fatigue, and then your next thrust would contain a ragged metal stick in someone's stomach.
I wouldn't use a metal golf shaft, but I would use a graphite golf shaft, if I could find them cheap at any of the thrift stores I go to. No luck yet.
3 pounds is nothing compared to that stop sign. XD
Chainsaw is an interesting weapon idea, but not on my immediate to-do list.
Glint has asked me to redo the tape in black, so I'll do that tomorrow. Also, I'm making the blades for the Vega claw, I'll put up pictures of how they look so far. Instead of cutting the blade edge like I usually do, I'll try melting the edges to a point with an iron and wax paper. If it isn't nice, I'll just saw off the melted portion. Right now the claws are a single layer of camp mat foam sandwiched between two layers of thin craft foam. I'm keeping these blades as thin as possible, since I need to fit 3 on a hand.