The problem with removing the wire core comes if you are bending it very much. Then, the now-hollow insulation tube can crease at the bend. If you leave the wire inside, it won’t crease. I sometimes strip the ends, then drill holes in a size appropriate for the core, to terminate at the end(s) with a strong bond. But I leave the core in.
Have you thought of Piano Wire or Guitar Wire?
STOVK,
Wire for stringed instruments is perfect for lots of projects. Guitar and Piano strings could be excelent for pipes ,cockpit cables, and hydralic lines. Wound Strings don’t do 90 degree bends well but they could curve around an object to simulate a reinforced tube or hose. Also, wound strings look a bit like Steel Cable or like they’re stropped (shrouds or forestay anyone?). Wound strings could be used to simulate heavy rope used as a bumper or fender on a LCVP or tug for instance. Strings stay straight if you’re careful but they also can show a natural sag when suspended (refuling at sea?).
IMHO these strings might not be good for some things. For instance, they might not make good eyebolts as it is very tough to twist them. I think a more malleable metal like copper wire would work better for that.
Note: Guitar and Piano strings can be dangerous. New strings come coiled and they can unwind and wack you. They can pr***/stick you when you are bending/handling them. Cut-off pieces fly off into the distant parts of the room never to be found till they’re found the hard way. Old/used Steel strings may have rust. So get your tetanus shot up to date.
Nino
The website listed below will have what you’re looking for. They carry a very large selection in flexible plastic. Hope this helps